Nanotechnology has remained relevant as a multifacet discipline, which cuts across different areas of science and technology. Several successful attempts had been documented regarding the involvement of biological materials in the green synthesis of various metal nanoparticles (MeNPs) because of their eco-friendliness, cost-effectiveness, safe handling, and ultimately less toxicity as opposed to the physical and chemical methods with their concomitant problems. Biological agents, including bacteria, fungi, algae, enzymes, plants, and their extracts, have been implicated in most cases by several authors. Moreover, nanotechnology in recent times has also made an inroad for animal species, specifically arthropods and metabolites thereof to be used as excellent candidates for the green synthesis of MeNPs. The increasing literature on the use of metabolites of arthropods for the green synthesis of nanoparticles has necessitated the need to document a review on their relevance in nanobiotechnology. The review, which represents the first of its kind, seeks to underscore the importance of arthropods in the multidisciplinary subject of nanoscience and nanotechnology.
Arthropods belong to the phylum Arthropoda, and this consists of the insects, arachnids, myriapods, and crustaceans. Arthropods possess distinct features, which include jointed limbs and cuticle composed of calcium carbonate and/or α-chitin . There are several millions of arthropod species varying between 1,170,000 and 5–10 million, and for this reason, they account for more than 80% of all known species of living animals and approximately two thirds of currently existing species . There are four major groups of arthropods: Chelicerata (horseshoe, spiders, and scorpions), Crustacea (shrimps, lobsters, and crabs), Tracheata (insects and myriapods), and the extinct trilobites, which were the first animals whose eyes were reportedly capable of high-degree resolution, with several other species that are well known . It has been established that insects and other arthropods provide condiments that have been highly essential and of utmost importance in traditional medicine for many years, particularly in some parts of Africa, East Asia, and South America .
Natural products, which are usually secondary metabolites, and their derivatives constitute more than 50% of the drugs used clinically for the treatment of diverse ailments world over. Many of these products are produced from plants, fungi, and bacteria . However, it has been reported that arthropods, being ubiquitous globally, have also played a vital role in the provision of inexpensive and abundant healing agents, most especially in countries where there are economic challenges . Some of the arthropods’ natural agents include bee venom containing varieties of peptides, including adolapin, mast-cell degrading peptide, melittin, phospholipase, and nonpeptide compounds, which all have useful applications in the treatment of cancer , , , control of diabetes , treatment of neurodegenerative disease , treatment of free radical-mediated disease , and treatment against HIV infection .
It was also reported that enzymes such as chymotrypsin, serine proteases, metalloproteinase, and aspartyl proteinase produced by maggots (larvae of Lucilia sericata, Lucilia cuprina, Calliphora vicina, and Phormia regina) play important roles in the healing of diabetic foot wound, postoperative infections, leg ulcers, and bed sores , , , . Furthermore, defensin, an enzyme produced by house flies alongside other factors, played an important role as an antibacterial agent against the methicillin-resistant Staphylococcus aureus (MRSA) and the vancomycin-resistant enterococci , . Cantharidin, a toxin produced from the bodies of several species of blister beetles, has also been found as a useful therapeutic agent. It has also been used for the removal of warts , treatment of cancer , , , , , , , and prevention of apoptosis and DNA damage . Polybia MPI, a novel antimicrobial peptide present in the venom of social wasp (Polybia paulista), was reported to be capable of cell membrane disruption and has also played a vital role in cancer therapy , .
Nanotechnology has continued to receive great attractions because of its widespread applications in different aspects of life endeavors. It is a subject that cuts across different fields of science and technology. The quest for nanomaterials that are environmentally benign, cost-effective, and nature-friendly has led to the green (biological) synthesis of metal nanoparticles (MeNPs) with the size range of 1–100 nm, and it is an attractive alternative to physical and chemical protocols. Several biological agents including bacteria, fungi, plants, enzymes, and extracts have been used for the biological synthesis of MeNPs , , , , , , , , , , , , , . However, there are few reports on the biological synthesis of MeNPs using metabolites of the arthropods. This article therefore seeks to review the involvement of several arthropods in the green synthesis of MeNPs as well as their various practical applications.
2 Honey bee
In this modern age, Apis mellifera, which is commonly called western honey bee, remains one of the few species having a considerable social impact . As one of the “eusocial” colonies of insects, honey bees are distinguished into two castes, the queen and the worker. The queen (usually one per colony) has the ability to procreate, whereas the workers amass food, take care of the young ones, construct the nest, and also secure the colony. Social evolution has provided the honey bee with unique characteristics , . The queen is capable of laying up to 2000 eggs in a day and store sperm for a long period without losing its viability. Its life span is estimated to be 10 times more than that of the workers (i.e. 1–2 years) .
There are a million neurons found in the honey bee (four times as much as that of Drosophila but five orders of magnitude less than that of humans) according to Witthöft et al. . Honey bees have the ability to learn abstract concept, which may be “same” or “different” . They are holometabolous organisms belonging to the same insect order (Hymenoptera) as species of ants, sawflies, and wasps. The male bees arise from unfertilized haploid eggs, whereas the females arise from fertilized diploid eggs; hence, they exhibit haplodiploid sex determination , . The suggested geographical regions where A. mellifera originated are Africa , Middle East , and Asia , and these creatures were reportedly carried by humans to all other parts of the world because of their ability to make honey .
3 Bee honey
For many centuries, honey as a natural product of honey bee, is renowned as a sweetening agent of mankind and is also considered as one of the healthiest foods ever known. Honey is composed of fructose and glucose as well as amino acids that help nourish the body and has been a subject of extensive study all over the world in terms of their physicochemical properties, mineral content, vitamins, and quality control , , , , . According to Philip , it was reported that the high energy, chemical constituent, vitamins, enzymes, and important minerals such as potassium and magnesium found in the honey help to elongate the life span of man. Honey plays an important role in the repair and regeneration of tissues. For instance, the 5.8-kDa of honey component isolated by Tonks et al.  was reported to induce the production of tumor necrosis factor-α cytokines via TLR4 in human monocyte cultures, which enhanced the repair and regeneration of damaged tissue.
There are also several reports on the use of honey in the treatment of wound infections, bedsores, and burns . In addition, the boundaries of knowledge of bees and their honey have been further extended as a result of their contributions to the advancement of nanotechnology. Following the necessity for safe, ecologically benign, and cost-effective natural agents in the synthesis of MeNPs, bees and bee honey have been used to mediate the biosynthesis of various MeNPs such as silver (Ag), gold (Au), cerium oxide (CeO), palladium (Pd), and copper oxide (Cu2O) nanoparticles (Table 1).
|Metabolites||Reaction conditions||Type of nanoparticles||Size (nm)||Shape||Applications||References|
|Bee honey||1 ml of the honey solution (1 g/100 ml distilled water)+ammonium solution/1 mm AgNO3 (1:2); 37°C (200 rpm); 24–72 h||Silver (Ag)||–||–||Antibacterial|||
|Bee honey||15 ml of honey solution+1 mm AgNO3; pH 8.5||Silver (Ag)||4||Spherical||–|||
|Bee honey||10 ml honey solution+30 ml HAuCl4; stirred; 3 h||Gold (Au)||15||Spherical||–|||
|Honey bee||Phosphate buffer treated ground bee (pH 7, 25 mm)+1 mm AgNO3+glucose; incubation (room temperature), 220 rpm||Silver (Ag)||12–18||Spherical||Treatment of colon cancer|||
|Bee honey||3 ml of honey+CuCl2.H2O+NaOH (2 g)+50 ml of distilled H2O; pH 12; stirred (room temperature, 30 min)||Copper oxide (Cu2O)||–||Spherical, pyramidal, and cuboidal||Antibacterial|||
|Bee honey||1–5 ml of honey solution+1 ml of 1 mm HAuCl4 (added up to 10 ml with distilled H2O); room temperature; 2 h||Gold (Au)||9.9||Spherical||Antibacterial and antifungal|||
|Bee honey||5 ml of honey+95 ml of 0.1 m AgNO3; stirred (under bright sunlight, 10 min)||Silver (Ag)||–||–||Prevention of mild steel corrosion in acidic environment|||
|Bee honey||50 ml of honey solution+cerium nitrate (Ce(NO3)3. 6H2O); stirred at 60°C (in oil bath); 6 h||Cerium (Ce)||23||–||–|||
|Bee honey||15 ml of honey solution+20 ml of AgNO3 (1 mm); pH 6.5–8.58||Palladium (Pd)||5–40||–||Cross-coupling for the synthesis of biaryls and hydrogenation of conjugated olefins|||
|Honey and Camellia sinensis fortified with lemon||5 ml of honey+50 ml of Camellia sinensis+5 ml of lemon juice||Silver (Ag)||34.5||Spherical||–|||
|Bee honey||15 ml of honey solution+20 ml of 0.1 mm AgNO3; pH 6.5–8.5; 1 min||Silver (Ag)||11.16–14.52||–||–|||
|Cobweb extract||1 ml of NaOH (0.1 m) hydrolyzed cobweb+40 ml of 1 mm AgNO3: room temperature; 8 min||Silver (Ag)||3–50||Spherical||Antibacterial, antifungal, additive in paint, and antibiotic improvement|||
|Paper Wasp-nest extract||1 ml of NaOH (0.1 m) hydrolyzed nest+40 ml of 1 mm AgNO3: room temperature; 8 min||Silver (Ag)||12.5–95.5||Anisotropic; sphere, 3D triangle, rhombus, rod, hexagon||Antibacterial, antifungal, dye degradation, anticoagulant, and thrombolytic activities|||
|Silk fiber||PAA modified silk+AgNO3 solution (0.02 mol/L)+UV light (365 nm); 2 h||AgNPs||–||–||Antibacterial activity|||
|SF||Aqueous SF solution+AgNO3 at pH 9–10||AgNPs||10||Cluster with core-shell structure||–|||
|SF||Aqueous SF solution+HAuCl4; pH 9–10||AuNPs||29||Core-shell structure||–|||
|RSF||Graphene oxide solution+10 ml RSF solution+HAuCl4 (25 mm); pH 7; 45°C; 5 min||AuNP/RGO composite||10||Flowerlike/monodisperse||Oxygen reduction reaction catalytic activity|||
|Silk films||Silk films+1 mm HAuCl4 in 0.1 m borate buffer at pH 10.5 or H2O at pH 3 for 10 h||AuNPs||6||Spherical/homogeneously disperse||–|||
|SF||SF solution+CdCl2 solution+Na2S solution+ternary solution (CaCl2: H2O: C2H5OH) at 45°C for approximately 1.5 h||QD-CDs/SF nanocomposite||5||Nearly round||–|||
|SF||SF irradiated with electron accelerator in air (1, 5, 10, 20, and 30 kGy)||WSSF-NPs||40||Spherical||Antioxidant, ferric reducing antioxidant power assay, and synthesis of AuNPs (WSSF-NPs+HAuCl4)|||
|SF||SF (0.04 wt.%)+Selenious acid solution (1 mm)+Ascorbic acid (4 mm)||SeNPs||–||Spherical/monodisperse||–|||
|SF||10 ml SF solution+10 mg AgNO3 powder+gamma radiation (10–80 kGy)||AgNPs||20–40||Roughly spherical with smooth edges/well dispersed||–|||
|SF||2 ml SF-cysteine solution at pH 10+2 mm HAuCl4 at room temperature||AuNPs||13±2.5||Monodisperse||Heterogeneous catalysis of p-nitrophenol reduction|||
|SF||2 ml SF-cysteine solution at pH 10+2 mm AgNO3 at room temperature||AgNPs||5±1.0||Monodisperse||Antibacterial activity|||
|SF||2 ml SF-cysteine solution at pH 10+2 mm Na2PdCl4 at room temperature||PdNPs||3±1.0||–|||
|SF||2 ml SF-cysteine solution at pH 10+2 mm H2PtCl6 at 85°C||PtNPs||2±0.2||–|||
|SF||AgNO3 powder (5–80 mg)+5 ml regenerated SF solution (1 wt.%) under light with an incandescent bulb for 2 h||AgNPs||12±2.1||Antibacterial and biofilm inhibition activity|||
|Sericin||SS (5–20 mg/ml)+AgNO3 solution (1, 5, and 10 mm) at pH 9 and 11 at room temperature; constant stirring.||AgNPs||46–117||Round||Antibacterial activity|||
|Sericin||0.5 ml NaBH4 solution+100 ml AgNO3 solution (0.29 mm)+SS solution||AgNPs||15||Spherical/fairly monodisperse||Antibacterial activities on fabric|||
4 Bee and bee honey-mediated MeNPs
4.1 Silver nanoparticles (AgNPs)
Silver is a nontoxic inorganic material recognized for possessing an inhibitory effect toward 650 types of microbes , and also displays the highest electrical and thermal conductivities among all the metals . AgNPs have a wide range of applications and the uppermost level of commercialization among the nanomaterials . For instance, among different nanoparticles that have been investigated, AgNPs are the most promising particles that are used in the field of nanomedicine for their antimicrobial activity against several microbes . Yezhelyev et al.  reported that AgNPs in the size range 1–100 nm is very advantageous for the diagnosis and treatment of cancers, which led to the new discipline of nano-oncology. AgNPs (not silver nanoclusters) became a member of antimicrobial silver family because of their elevated specific surface area and prominent fraction of surface atoms than bulk silver. It has also been proposed that AgNPs interact with the bacterial membranes to cause structural alteration and degradation of cells. AgNPs destroy permeability of outer membrane, hinder respiration and growth of cells, and obliterate the structure of membrane, leading to cell decomposition and death eventually , and may cause apoptosis through the arrest of G0/G1 cycle . It has become increasingly clear that nanoparticles play prominent roles in the treatment of cancer, including the use in targeted drug delivery .
Singh et al.  demonstrated the biosynthesis of AgNPs using bee honey. Honey was boiled in deionized water and added to 1 mm concentration of silver nitrate and ammonium solution. The change in the color of the solution from bright yellow to dark brown (after 72 h of reaction) indicated the formation of nanoparticles. The biosynthesized AgNPs maximally absorbed at 420 nm when subjected to UV-Vis spectroscopy. Observation of this peak showed the extracellular reduction of Ag+ ions. The Fourier transform infrared (FTIR) spectroscopy of the AgNP solution also revealed proteins as the biomolecules responsible for the stabilization of the biosynthesized AgNPs. The AgNPs were reported to have excellent antimicrobial activity against MRSA. Moreover, following the bioreduction of the silver ions in the solution using bee honey, Philip  reported the synthesis of AgNPs visually characterized by the formation of golden yellow color. The biosynthesized AgNPs were characterized using analytical techniques such as UV-Vis spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Maximum absorption at 413 nm and monodispersed spherical-shaped nanoparticles with an average size of 4 nm (as revealed by TEM) were observed. XRD revealed the biosynthesized nanoparticles as nanocrystallites, which were 6 nm in size. Although glucose in honey was suspected for the reduction process, proteins present in the honey were reportedly responsible for the stabilization of AgNPs.
El-Deeb et al.  investigated the involvement extract of dried bee in the synthesis of AgNPs. The extract of the honey bee was reacted with 1-mm silver nitrate as a substrate for the synthesis of the nanoparticles. There was noticeable change in color of the solution (indicating the formation of AgNPs) with maximum absorption at 450 nm. The nanoparticles were spherical with carbon, oxygen, and silver being the most prevalent elements according to TEM and energy-dispersive spectroscopic (EDX) analysis. The biosynthesized AgNPs were proposed as a promising agent in drug delivery and colon cancer therapy because of their anticolon cancer activities at both the cellular and the molecular level. In another study, Obot et al.  reported the formation of stable AgNPs with characteristic yellow brown color when 5 ml of bee honey was reacted with 95 ml of 0.1 m silver nitrate after exposing honey-AgNO3 solution to sunlight. The absorbance peak was found at 450 nm. The suggested reducing agent in the honey was fructose, whereas proteins were found to be responsible for the stabilization of the resulting AgNPs. The nanoparticles displayed a high level of corrosion inhibition of mild steel in 0.5 m HCl, producing an inhibition efficiency of 91.5%, with a treatment of 6% v/v of AgNPs.
Different levels of local honey from Malaysia used for the synthesis of AgNPs were reported by Haiza et al. . By modulating the pH of AgNO3 and local honey as well as their concentrations, AgNPs of different morphologies were synthesized. The color of the AgNPs formed was golden yellow. As the concentration of the honey increased, the size of the nanoparticles decreased and vice versa in the range of 15.63–26.05 nm. The biosynthesized AgNPs were characterized using UV-Vis spectroscopy, FTIR, SEM, and field emission scanning electron microscope. The absorbance peaks of AgNPs at pH of 6.67, 7.00, 7.51, and 8.01 were 490, 482, 430, and 424 nm, respectively. The biosynthesized nanoparticles were anisotropic with polydispersed distribution. The reducing and stabilizing agents in the honey-AgNO3 solution were glucose and protein, respectively.
The involvement of extract of plant fortified with honey also mediated the synthesis AgNPs under sonication according to Kothai and Jayanthi . The extract of Camellia sinensis fortified with lemon and honey was reacted with 0.001 m AgNO3. As the reaction proceeded, the color of the solution changed from pale yellow to reddish brown, indicating the formation of AgNPs. The analytical techniques used included UV-Vis, FTIR, EDX, and SEM. The absorbance peak was observed at 425 nm. Water-soluble alkaloids, flavonoids, and phenols were reported as the capping and stabilizing agents with elemental silver being the most prevalent in the solution. The nanoparticles formed were spherical in shape and polydispersed in distribution with the size range of 30.2–75.4 nm.
4.2 Gold nanoparticles (AuNPs)
MeNPs, particularly AuNPs, have remarkable biocompatibility and nontoxicity. Moreover, it is less oxidizable substance than silver and, thus, can be used for long-term applications. Antibodies and proteins can be conjugated to AuNPs through definite thiol functionality, which makes them significant for biochemical detection and therapeutic functions . AuNPs are extensively studied because of their explicit optical, catalytic, electric, and delivery properties . Uniform nanostructures with a range of morphologies have been produced, such as wires , spheres , plates , cubes , dendrites , and flowers . It has been described that thiol moiety (–SH) can capably advance the stability and dispersity of colloidal noble MeNPs, particularly to AuNPs in solution, compared with other functional groups (–NH2, –COOH, etc.), and this is mainly because thiol (–SH) groups bind covalently to the surface of AuNPs . Several reports also support the interface of thiol moiety with Ag, Pd, and Pt nanoparticles .
Philip  demonstrated the use of honey in the biosynthesis of AuNPs. Natural honey was dissolved in deionized water, and the mixture was reacted with gold chloride (HAuCl4) solution. The AuNPs formed after the bioreduction of AuCl4− were light purple in color, and the maximum absorbance of the particles was obtained at 541 nm. The sizes of the nanoparticles reduced as the quantity of the honey increased. The nanoparticles produced were anisotropic structures of sphere, rod, and triangle as revealed by TEM. Other analytical techniques used were XRD (which confirmed the crystalline nature of the biosynthesized AuNPs with an average size of ~ 15 nm) and FTIR, revealing protein as the capping and stabilization biomolecule. The nanoparticles were also suggested for therapeutic use because of their photoluminescence potentials. The AuNPs produced photoluminescence at 447 nm because of functionalization with honey.
Sreelakshmi et al.  reacted different volumes of honey solution (water/honey) with HAuCl4 separately, with the color of the reaction mixtures turned pale yellow at the end of the experiment, indicating the synthesis of AuNPs. Absorbance peak was observed at 550 nm. The AuNPs (diameter 9.9 nm) were spherical in shape and crystalline in nature as revealed by TEM and XRD. They also showed an excellent growth inhibition of test Gram-positive and Gram-negative bacteria, including antibiotic-resistant strains as well as Candida albicans. The MIC of 31.25 μg/ml was obtained against S. aureus MTCC 1144, whereas 62.5 μg/ml was obtained against Escherichia coli MTCC 739, Salmonella typi MTCC 733, Streptococcus mutans MTCC 890, and C. albicans MTCC 183.
4.3 Cerium oxide nanoparticles
Darroudi et al.  established the involvement of honey bee in the synthesis of cerium oxide nanoparticles (CeO2NPs) – a rare-earth material. The solution of honey was made by dissolving honey in distilled water. The solution was well stirred under room temperature. Cerium oxide was reacted with a clear solution in a reaction vessel placed in an oil bath at 60°C, and a light yellow color resin was obtained after stirring and was also divided into parts. Exposure to different calcinating temperatures (200–800°C) and subsequent maintenance of the product at specific temperatures in air led to the formation of CeO2NPs. The sol-gel derived CeO2NPs with aqueous honey solution as a greener capping and stabilizing agent changed from black color to lemon and finally white as a result of an increase in calcinating temperature. Absorption peak was observed at 314 nm. Other analytical techniques used included field emission electron microscope, powder XRD, energy-dispersive spectrum, FTIR, and thermogravimetric analysis. The biosynthesized CeO2NPs were approximately 23 nm and isotropic with CeO2 as the most prevalent compound in the sample. By using the neuro2A cells, the nontoxicity of the synthesized CeO2NPs at concentrations lower than 25 μg/ml was demonstrated. The study concluded that the green method could be used for the synthesis of CeO2NPs, avoiding hazardous materials/steps.
4.4 Palladium, copper oxide, and platinum nanoparticles
Reddy et al.  synthesized palladium nanoparticles (PdNPs) by reacting bee honey solution (water/honey) with palladium chloride (PdCl2) in acidic medium. The absorption bands of biosynthesized PdNPs at 223 and 280 nm confirmed the total reduction of Pd ions. XRD pattern showed the biosynthesized nanoparticles as crystalline solid with face-centered cubic structure. EDX result revealed strong Pd spectra with carbon and oxygen as functional entities. The nanoparticles were within the range of 5 and 40 nm according to SEM analysis. The biosynthesized PdNPs were used in Suzuki cross coupling for the synthesis of biaryls and also for the hydrogenation of conjugated olefin because of their catalytic property.
Polycrystalline copper oxide (Cu2O) is a semiconducting material used as one of the constituents of paints and as antitumor agent , . Ali et al.  investigated the use of honey to mediate the synthesis of their nanoparticles. Solutions of edible honey, copper chloride dehydrate, and NaOH in distilled water were reacted together and stirred at room temperature with pH 12. However, different solvents were used to obtain the final product for comparison. The resultant Cu2O nanoparticles (Cu2ONPs) were observed to have brick red color. The nanoparticles were spherical in shape and crystalline in nature with Cu (I)-O stretching according to SEM, FTIR, and XRD analysis. The nanoparticles produced inhibited the growth of S. aureus and E. coli within 13–14 mm.
Venu et al.  have demonstrated the synthesis of platinum nanoparticles (PtNPs) and nanowires using honey. The reaction conducted at 100°C for 2 h led to the formation of PtNPs, having the size of ~2.2 nm, whereas at longer heating of 4–20 h, nanowires of 5–15 nm in length were obtained through the self-assemblage of PtNPs. The particles absorbed maximally at 533 nm, indicating the formation of PtNPs. The FTIR showed that particles were formed as a result of reduction by proteins through binding with carboxylate ion, whereas the XRD showed the formation of highly crystalline particles with face-centered cubic structure. The catalytic application of synthesized PtNPs was demonstrated through the synthesis of an organic dye, antipyrilquinoneimine, with the potential for detection and removal of anilines from water and soil.
Spiders are creatures with four pairs of legs. They have chitinous coverings and two body regions, which are divided into cephalothorax and abdomen. The cephalothorax consists of head and thorax combined together as one external unit . Of approximately 1.7 million species of bacteria, plants, animals, fungi, and protists described according to DMNS , the proximate figure of species of spiders in the World is 40,000 . Many species of spiders construct webs, specifically the orb webs . Many times, the production of silk evolved in arthropods ; however, spiders are recognized as notable and excellent silk craftsmen. They use different types of silk threads to form an array of structures, which range from simple lifelines to shelters for moulting, from egg sacs to webs, and also for ballooning (dynamic kitting) .
6 Cobweb (spider silk)
Silk can be loosely defined as fibrous proteins that are extended outside an organism body and are composed of semicrystalline molecular structures . Spider silk is spun by spigots found on the spinnerets (which are three pairs of appendage-like organs) on the abdomen of the spiders. Spider silk has been reported to have unique chemical, molecular structure, and molecular properties . Silk fibers produced ranked among the strongest, stretchiest, and toughest biomaterials known and are therefore common subjects of behavioral and ecological research .
Spiders invest physiologically important compounds in the construction of their webs. Most spider silks consist of proteins that are composed of highly repetitive amino acids “motifs”, that is, short amino acid sequence mainly consisting of highly repetitive glycine and alanine blocks , which is why silks are often called block copolymers. Pyrrolidine, a nonprotein compound that has hygroscopic properties, helps to keep the silk moist and also wards off ants invasion. Potassium hydrogen phosphate found in spiders produces a photon that reduces the pH to 4, thus making the silk acidic. This protects the silk from bacteria and fungi, which could otherwise digest the protein . Potassium nitrate and phospholipids found in the silk are believed to prevent the protein from denaturation in the acidic milieu (surrounding) and also to prevent the growth of fungi and bacteria on it , , . Other components include phosphorylated glycoprotein, pigments, and lipids, which enhance good adhesive property of the silk fiber. They are nutritionally important, and they act as a protection layer in the fiber , .
Carpathian mountain dwellers used the tubes of silk produced by a spider species, Atypus, to cover their wounds, and the silk reportedly facilitated the healing of the wounds because of its antiseptic properties . Also, because the silk is rich in vitamin K, it is considered to be effective in blood clotting . It was reported that the web of Nephila was used by the fishermen in the Indo-Pacific ocean to catch small fish . The silk of Nephila clavipes was also used to help in mammalian neuronal regeneration . At one time, spider silk was commonly used as a thread in optical devices such as telescopes, microscopes, and telescopic riffle sights. Several studies have also shown that some of bisphosphonate peptides that have antibacterial activity could be found in the spider silk . Roozbahani et al.  evaluated the antimicrobial activity of the silk of the spider Pholcus phalangioides against food-borne bacterial pathogens. Spider cobwebs have also been used for the monitoring of pollution in industrial and residential areas , , and spiders have been used as biocontrol agents in reducing populations of insect pests on farmlands . In addition, venoms of spiders have been evaluated for the treatment of cardiac arrhythmia , Alzheimer’s disease , and erectile dysfunction .
On the account of the combination of excellent mechanical properties, biocompatibility, and slow biodegradability, spider silk has found tremendous applications in biomedical field, such as tissue engineering , and also as additives in cosmetic products, such as shampoos, soaps, creams, and nail varnish, enhancing the brightness, softness, and or toughness of the products . Furthermore, spider silk fibers could be applied in technical textiles (used, for example, in parachutes and bulletproof vests), which demand high toughness in combination with thinness . The quest for biological material that could be used in the area of nanotechnology for the synthesis of safe, eco-friendly, and cost-effective MeNPs has further led to the exploration of spiders for the synthesis of nanoparticles.
7 Cobweb-mediated synthesis of AgNPs
In our laboratory, we have further extended the limits of knowledge on biotechnological applications of biosynthesized AgNPs through the first report of the use of spider cobweb as a novel biomaterial to synthesize AgNPs . The cobweb extract obtained by alkaline hydrolysis of cobweb using NaOH under appropriate conditions was reacted with 1 mm AgNO3 solution. As the reaction (extract/AgNO3 solution) proceeded under static condition (at room temperature), a dark brown color resulting from AgNPs synthesis was formed. The biosynthesized nanoparticles were characterized using analytical techniques, including UV-Vis spectroscopy, FTIR, TEM, EDX, and selected area electron diffraction (SAED) analysis. The AgNPs produced showed a maximum absorbance at wavelength of 436 nm. The nanoparticles were crystalline in nature and spherical in shape with polydispersed distribution, and their sizes ranged between 3 and 50 nm (Figure 1). The biosynthesized nanoparticles inhibited the growth of test clinical bacterial isolates and also potentiated the activities of cefixime, augmentin, and ofloxacin to the tune of 3.9%–100%, 6.3%–100%, and 3.1–20%, respectively, against multiple drug-resistant organisms, including S. aureus, Klebsiella granulomatis, Pseudomonas aeruginosa, and E. coli (Figure 2). The AgNPs were therefore suggested as an antibacterial agent for clinical applications. The nanoparticles were also reportedly useful as an additive in emulsion paint for quality improvement and for the prevention of microbial attack, through the complete obliteration of deteriorating bacterial and fungal species that were inoculated in to the emulsion paint (Figure 3).
8 Paper wasps
Paper wasps belonging to the genus Polistes have been studied in details among the eusocial wasps (Hymenoptera, Vespidae, and Polistinae), with the report of existence of approximately 200 cosmopolitan species , , . Polistes live in groups of approximately 100 individuals per colony in nonenveloped nests. The nests are constructed on surfaces, such as twigs, leaves, dense shrubs and grass, hollow trees, and elevated natural cavities and man-made structures , . These nests, which are paperlike, are derivatives of the eating habits of wasps on plant resources  and are used by female wasps as sites to lay eggs. The nests are rich in cellulose and proteins, with the reported occurrence of more than 20 amino acids obtained in field and laboratory nests; the most frequently occurring amino acids are glycine, serine, alanine, valine, and proline , , . Antimicrobial metabolites, such as Dominulin A and B, have been reported from the cuticle and venom of Polistes dominulus, producing MIC of 2 and 8 μg/ml against Bacillus subtilis and E. coli . However, the metabolites of paper wasps have not been adequately exploited for the green synthesis of nanoparticles.
9 Synthesis of AgNPs using hydrolyzed nest of paper wasp
We have recently reported the first study on the green synthesis of AgNPs in our laboratory using the hydrolyzed nest extract of Polistes sp. . The nest was hydrolyzed with 0.1 m NaOH at a temperature of 90°C for 1 h, and the supernatant was used for the green synthesis of AgNPs without further purification (Figure 4). The crystalline AgNPs (12.5–95.55 nm) had surface plasmon resonance attained at 428 nm, with the formation of anisotropic structures of sphere, 3-D triangle, rhombus, hexagon, and rod (Figure 5). FTIR data suggest that proteins and phenolic compounds were involved in the synthesis of AgNPs. The nest extract-mediated AgNPs depicted good antimicrobial activities against K. granulomatis and P. aeruginosa in the range of 12–35 mm. Similarly, at 100 μg/ml, the AgNPs produced 100% against Aspergillus niger and Aspergillus flavus, whereas 75.61% was obtained against Aspergillus fumigatus. Furthermore, the AgNPs degraded malachite green by 64.3%–93.1% within 24 h. The biomedical application of AgNPs in the management of blood coagulation disorders was demonstrated, with the particles showing very good blood anticoagulation and clot dissolution (thrombolysis) activities in vitro (Figure 6).
10 Silkworm and silk waste
The silkworm is the larva of the domestic silk moth Bombyx mori. It is an economically essential insect, being a principal producer of silk. Silk waste is a major part of the cocoons of silkworms (B. mori) . Although it is inapt for silk textile production, the composition of such silk waste is comparable with that of good silk . It is made up of fibroin core polymer (75%–83%) and sericin gluelike protein as a covering (17%–25%). The primary structure of silk fibroin (SF) polymers largely consists of the amino acid sequence of (Gly-Ala-Gly-Ala-Gly-Ser)n, existing in glycine (Gly, 43%), alanine (Ala, 30%), and serine (Ser, 12%) components , . Fibroin and sericin are the two proteins in unprocessed silk spun from the silk glands of adult caterpillars belonging to the species B. mori. Fibroin is enclosed by the gumlike substance sericin, which composes of approximately 25% of raw silk, whereas sericin is typically removed as waste in the process of silk enhancement . Both raw silk proteins have been used in the green synthesis of various MeNPs (Table 1).
11 Silk fibroin
Silk fibroin fiber (SFF) is a natural protein or biomaterial generally obtained from silkworm B. mori cocoons. It has been found that SF has unique properties for being used as healthy foods, enzyme immobilizing materials, cosmetics, cell culture medium, biosensor, artificial skin and muscle, permeable membrane, and drug release substances. It has attracted wide interest in many fields, including polymer technology, biology, materials science, medicine, sericulture, and chemical engineering, leading to the increase in studies on silk protein , , . Because of its notable biocompatibility with human tissue, biodegradability, flexible morphology, drug permeability, nontoxicity, and good mechanical property , SF is of great significance in the field of biomedicine and applications in health care materials, such as food and cosmetic additive, tissue engineering , and drug delivery method , . SF protein from B. mori silkworm is FDA permitted, and it has been used in biomedical applications, developed as scaffold materials and effectively used in healing of wounds and in tissue engineering of bone, tendon, cartilage, and ligament tissues , . Also, it exhibits inflammatory response although less than collagen .
In recent times, it has been reported that SF produced from B. mori harbors antioxidant and hypolipidemic properties , . It is of great importance as a natural antioxidant for applications in food, pharmaceutical, cosmetic, and biomedicine . In investigating the interaction between silk protein and noble metal ions, the silk protein has the exceptional property to prepare nanocolloidal metal particles . Water-soluble fibroin protein has 18 species of amino acid residues such as alanine, glycine, serine, and tyrosine, and it is prepared by destroying hydrogen bonds in SF and dissolving them in water , making them more effective in nanocolloid synthesis. This gives SFF potential to provide various reactive sites for bioinspired processes, as well as to become possible biomaterials for the synthesis of functional nanocomposites under mild conditions. SF has been used in micro- and nanoparticles for drug delivery applications . The SF nanoparticles have been produced using emulsion-solvent evaporation/extraction, self-assembly, solvent displacement, phase separation, rapid expansion of supercritical solution, and spray-drying techniques . Different inorganic materials such as silica, magnetite, apatite, titania, silver chloride, zirconia, and MeNPs have been deposited onto or within silk matrices to increase mechanical and optical properties .
SF for the synthesis of nanoparticles can be acquired by removing the outer sericin of silk fibers with anhydrous sodium carbonate solution at an appropriate temperature. SF may adapt the interface of nanoparticles, manage the growth of nanoparticles, and stabilize the nanoparticles solution . Many potential applications of SF-noble metal nanocolloids, especially in biotechnology such as immunoassay, DNA identification, biosensor, and inspection, gene therapy, will gain prominence in research .
12 Synthesis of nanoparticles with SF
12.1 Silver nanoclusters and nanoparticles
Silk templates have been used as a matrix for the incorporation of preformed AgNPs and also for binding metal ions from solutions and their consequent chemical reduction . Wang et al.  demonstrated the in situ growth of Ag nanoclusters on silk fibers, which resulted in a novel composite silk fiber with luminescence and strong antibacterial activities against E. coli and S. aureus. The synthesis involved soaking polyacrylic acid-modified silk into an aqueous silver nitrate solution (0.02 mol/l) and then irradiating it using 365 nm ultraviolet (UV) light lamp. Under the UV light, silk fibers transformed color from white to pink, signifying the formation of Ag nanoclusters. The characterization of the Ag nanocluster using the UV-Vis absorption spectra indicated an absorption peak of approximately 490 nm, which is associated with Agn nanoclusters (n=4–9) . The fluorescence emission spectra showed strong emission band traversing from 500 to 700 nm under the excitation of 450 nm. Also, the images from confocal microscope proved that the Ag nanoclusters displayed the luminescence emission properties. The X-ray photoelectron spectroscopy (XPS) measurements showed the characteristic energy values of metallic Ag (0), signifying Ag (I) ions were reduced to Ag atoms.
Chen et al.  reported the synthesis of metal nanocolloid by SF solution in situ reduction in which SF acted as both reducing agent and protector. This kind of noble metal nanocolloid has a novel core-shell structure with a stable and highly dispersed nature. Aqueous SF solution was reacted with AgNO3 solution at room temperature. Ag nanocolloid synthesis was signified by the gradual change of the silver solution from a chromic into yellow after a period. The UV-Vis spectra indicated a symmetric absorption band appearing at 420 nm; the colloids were monodisperse, around spherical, and size distribution was reportedly narrow. FT-IR measurement showed peaks at 1622, 1512, and 1262 cm−1 relating to amide I, amide II, and amide III bands, respectively. Also, amide IV band was obtained at 694 and 642 cm−1. The morphology of the nanocolloid was observed using TEM, which indicated that the silver nanocolloid was formed as a cluster that has more than 10 core-shell structured silver-SF particles. The average size of the silver cores was reported as approximately 10 nm.
Recently, a gamma radiation-assisted biosynthesis of AgNPs using SF was reported by Kumar et al. . Silver nitrate (AgNO3) powders were added to SF solution, and the mixture was then exposed to gamma radiation of different doses from 10 to 80 kGy. Color change from colorless to yellowish then to dark brown was observed, and the formation of the Ag NPs was established by its typical surface plasmon resonance band at approximately 424 nm in UV-Vis spectra. The FTIR spectra revealed peaks indexed as belonging to amide I, amide II, and amide III bands. The XRD analysis confirmed the nanocrystalline phase of silver with fcc crystal structure. The TEM images showed that the nanoparticles were roughly spherical in shape. Also, the results from the dynamic light scattering (DLS) study showed that the average size nanoparticles formed in SF ranged from 20 (at 60 kGy) to 40 nm (at 20 kGy), indicating that increasing the radiation dose increases the rate of reduction and decreases the particle size. Thus, the size of the AgNPs can be tuned by controlling the dose of radiation.
SF was also used as a biotemplate for the synthesis of AgNPs in situ under both incandescent light and sunlight at room temperature in a study reported by Fei et al. . The AgNPs showed effective antibacterial activity against the MRSA and consequently inhibited the biofilm formation caused by the same bacterium. Moreover, it was confirmed that a matured biofilm created by the MRSA can be destroyed by the SF-AgNP composite. Silver nitrate powder was added to approximately 1 wt% regenerated SF solution, which was then exposed under the light with an incandescent bulb and incubated at room temperature for 24 h for reduction and synthesis. It was believed that SF was capable of reducing Ag+ to Ag by the redox-active nature of tyrosine residues in its chemical structure. Color change from colorless to yellow was observed, and UV-Vis spectra showed absorption peak at 440 nm with small shoulder found at 347 nm, suggesting the possible existence of different sizes and morphology of AgNPs . The TEM micrograph showed that the average size of AgNPs was approximately 12 nm, and the high-resolution transmission electron microscopy image of an individual nanoparticle indicated that the d-spacing of the crystallographic plane was 0.23 nm, which agrees well with the distance of (111) lattice plane of Ag . Also, EDX confirmed that the local elemental composition of the product was Ag, and SAED confirmed the single crystal nature of the synthesized AgNPs.
12.2 Gold nanoparticles
Silk was also found to condense metal ions from aqueous solution without additional reducing agents, leading to the one-step in situ synthesis of MeNPs at ambient conditions. This method was applied to SF solutions at alkaline conditions to attain colloidal core-shell gold-silk nanoparticles with high monodispersity. Silk microfibers having diameters of 2–5 μm have also been used as solid templates for the reduction of gold and silver nano- and microparticles . Chen et al.  synthesized gold nanocolloid by reacting aqueous SF solution with HAuCl4 solution at room temperature. The synthesis of nanocolloid was indicated by the gradual change in color of gold solution from yellow to purple. The UV-Vis absorption spectra showed an absorption peak at approximately 520 nm, and pH 9–10 was observed as the best condition for reduction. Characteristic amide bands in FTIR spectra of the gold nanocolloid were reported with peaks at 1621, 1515, 1262, 1232, 697, and 615 cm−1. The TEM showed the morphology of the nanocolloid as gold colloid-SF bioconjugate of sizes ranging between 40 and 60 nm. The nanocolloid was a novel core-shell structure with gold cores (approximately 29 nm) covered by SF. The gold colloid was very stable and dispersed in nature.
Flowerlike AuNP/reduced graphene oxide (RGO) composites were produced by Shengjie et al.  in a simple, one-pot, environmentally friendly method with regenerated silk fibroin (RSF) as the reducing agent and adhesive for binding AuNPs and RGO. This was based on the fact that RSF can be simply and firmly absorbed onto RGO surfaces by π–π stacking and H-bonding, whereas the –NH2 and –COOH groups on RSF chains can function as nucleation sites for MeNPs. The effects of reaction time, temperature, and HAuCl4: RGO ratio on the morphology of AuNPs overloaded on RGO sheets were examined. Also, the flowerlike AuNP/RGO composite showed good catalytic performance for oxygen reduction reaction. AuNP/RGO composite was prepared by reacting 25 mm HAuCl4 solution with RGO solution at 45°C for 5 min. The UV-Vis spectra indicated various peaks depending on the temperature of synthesis. The AuNP/RGO composite prepared at room temperature exhibited peak at 528 nm, 37°C at 538 nm, and 45°C at 645 nm. The SEM image revealed that the AuNPs were nearly monodispersed in a size of 200–300 nm with rough surfaces. Enlarged image illustrated that AuNPs were flowerlike and composed of some 10-nm nanoparticles. The image from the TEM showed that the AuNPs were not arranged very compactly, resulting in possible relevance in catalysis. SAED showed diverse diffraction pattern, including (111), (200), and (220) faces, signifying the existence of defects and multiple crystal domains in the Au crystals . It was ascertained that by changing reaction parameters such as reaction time, temperature, and pH, the size, shape, and crystal aggregation of the AuNPs loaded on RGO could be regulated.
A study has also established a simple and adaptable strategy to generate ultrathin nanocomposite silk films with evenly dispersed AuNPs at ambient conditions . It was also established that both silk I and silk II forms were capable of metal reduction, and the reduction did not alter the initial secondary structures of silk surface layers for both silk I and silk II types. For synthesis, the silk films were immersed into 1 mm HAuCl4 solution at room temperature in 0.1 m borate buffer at pH 10.5 or into water at pH 3 for 10 h. Characterization by UV-Vis spectra showed peak at 547 nm, and FTIR spectra showed a typical amide I band (1600–1700 cm−1), which is related with C=O stretching in the protein backbone joined to the N-H bending and C=N stretching modes . The major peak centered at 1644 cm−1 relates with silk I spectra. There was no difference in the spectra of both silk I and silk II before and after mineralization, signifying that gold formation did not bring about any conformational transformation in silk structures. The TEM images showed that the AuNPs were evenly distributed over the surface with diameters of approximately 6.7 nm, and the sizes of nanoparticles were approximately 7.0 nm.
Recently, Wongkrongsak et al.  described the synthesis of water-soluble silk fibroin nanoparticles (WSSF-NPs) using electron beam irradiation. The electron beam irradiation reduced the molecular weight of SF from 250 to 37 kDa. The synthesized WSSF-NPs irradiated with electron beam doses ranging from 1 to 30 kGy showed effective antioxidant activities with EC50 for scavenging DPPH ranging from 0.27 to 0.98 mg/ml. Also, the ferric reducing antioxidant power assay indicated that relative reducing power increased along with the increase in concentration of the WSSF-NPs. Moreover, the WSSF-NPs displayed potent reducing agent for the green synthesis of gold nanocolloid. WSSF-NPs were synthesized by irradiating the aqueous solution of SF with an electron accelerator in air at different doses of 1, 5, 10, 20, and 30 kGy. FTIR spectrum showed three major peaks at 1630 cm−1, 1520 cm−1, and 1260 cm−1 belonging to C=O (amide I), N-H (amide II), and C-N and N-H (amide III), respectively. The FTIR spectrum also showed the peaks at 3280 cm−1 interpreted as N-H stretching and the peaks at 2930 and 2960 cm−1 belonging to C-H stretching of the amino acid. SEM and TEM micrographs indicated that the WSSF-NPs were loosely packed spherical particles and they have an average diameter of approximately 40 nm. The WSSF-NPs also mediated the synthesis of gold nanocolloid by reacting 10-kGy irradiated WSSF-NPs with 0.1 mm HAuCl4 for 24 h. Color change from pale yellow to dark violet color was observed, and UV-Vis spectrum indicated various peaks for the gold nanocolloid at 545, 550, 555, and 560 nm depending on the concentration of WSSF-NPs added.
12.3 Cadmium and selenium nanoparticles
A suitable room temperature bioinspired system was developed by Su et al.  to synthesize hybrid quantum dot (QD)-cadmium sulphate (CdS)/SF colloid, in which SF functioned as both natural biocompatibilizer and capable passivator of trap sites on the QD-CdS surface, which could be of use in photocatalysts, novel luminescence, and photoelectron transfer devices and also for some possible usage in the biological fields. QD-CdS/SF nanocolloids consist of well-diffused QD and the substrate SFF. QD-CdS as typical II–VI semiconductor nanoparticles are studied widely because of their range of properties, including unique optical properties, photocatalytic and tunable photoluminescence with high quantum yield, and broad excitation wavelength scope .
For the synthesis of QD-CdS/SF nanocolloids, a certain amount of SF were dipped into CdCl2 solution, rinsed, and immersed into Na2S solution for some hours. Then it was observed that the SF changed to a yellowish color. The yellowish fibers were washed and dried in vacuum at room temperature. The yellowish solid sample gotten was immersed in the ternary solution (CaCl2:H2O:C2H5OH=1:8:2 [molar ratio]) at 45°C to dissolve the SF and to obtain a clear yellowish QD-CdS/SF colloid, which was steady at room temperature. The UV-Vis spectra characterization of the nanocolloid showed peak at 482 nm, and results of FTIR showed peaks at approximately 1645 and 1702 cm−1 (amide I bands) due to C=O stretching, at approximately 1515 cm−1 (amide II bands) due to N-H bending, and at approximately 1230 and 1261 cm−1 (amide III bands) due to vibrations involving O-C-N and N-H. Also, the peak in the region of 1645 cm−1 of the C=O stretching band shifted to 1657 cm−1, revealing the chelation between Cd2+ and C=O from peptide bonds of SFF. The photoluminescence spectra showed a smooth broad peak that centered at approximately 450 nm, which indicated the formation of energy bands that may be because of the chelation of Cd2+ with the C=O from the peptide bonds of SFF. SAED revealed that CdS has hexagonal (greenockite) structure with significant planes indexed to (101), (102), (110), and (103) of greenockite CdS. The TEM image showed that the QD-CDS/SF nanocolloids were nearly round spheres with an average diameter of approximately 5 nm.
A solution-phase approach to the synthesis of selenium nanoparticles by mixing appropriate amount of SF with selenious acid solution, with the addition of ascorbic acid solution to initiate reaction, was reported by Xia . Color change from colorless to red was observed. The nanoparticles were characterized by atomic force microscopy (AFM) and X-ray techniques, and the effects of temperature and ultrasonication on the morphology of selenium nanoparticles were also discussed. AFM indicated that the nanoparticles were monodispersed uniform spherical selenium colloid particles that were enveloped by SF. Also, results from XRD indicated that the nanoparticles were amorphous. The selenium nanoparticles were also reported to be stable.
12.4 Silver, gold, platinum, and palladium nanoparticles
Furthermore, Das and Dhar  demonstrated the use of cysteine-modified SF as a reducing agent, stabilizing agent, and material matrix in the synthesis of noble MeNPs (Au, Ag, Pd, and Pt), which was done by a facile one-pot procedure using silk fibroin-cysteine solution (SF-SH). The integration of thiols (–SH) into SF led to the formation of almost monodispersed MeNPs. In the synthesis, the aqueous solution of SF-SH at pH 10 was added to an aqueous solution of 2 mm of metal precursor (HAuCl4, AgNO3, and Na2PdCl4) at room temperature. The same method was followed at 85°C in the case of platinum. Color changes were observed as follows: AuNPs, yellow to light purple to purple to wine red; AgNPs, colorless to blackish brown; and PdNPs, yellow to colorless. However, PtNPs were not formed at room temperature by using the same reaction procedure. The UV-Vis spectra of the synthesized Au and Ag-SF-SH conjugates showed a strong absorption band at 524 and 410 nm, respectively, which were measured to be intact after a month. For Pd and PtNPs, the absorption band of the salt vanished, and there was no peak generation that may validate the formation of zero valent MeNPs. The XRD analyses show the formation of nanoparticles with strong peaks corresponding to (111), (200), and (220) based on the face-centered cubic (fcc) structure of Au and AgNPs. For PdNPs, only peak at 200 was the major peak, and PtNPs showed 111 and 200 peaks. Also, the TEM micrograph showed that the Au and Ag, Pd, and PtNPs had narrow distribution particle size of approximately 13.0, 5.0, 3.0, and 2.0 nm, respectively. The accessibility of catalytic site of nanoparticles in these biohybrid materials was demonstrated by 4-nitrophenol reduction by using NaBH4. Moreover, the 3D porous scaffold of high mechanical strength from the Au-SF-SH and Pd-SF-SH conjugate materials was also obtained, which facilitated heterogeneous catalysis. The AgNPs composite film showed very fine antibacterial activity against E. coli. Therefore, these NP-SF conjugate materials have potential for applications in catalysis and biomedicine.
Silk sericin (SS) is a water-soluble protein obtained through silk refinement. Presently, SS is regarded as a waste product from the textile industry. It is extremely hydrophilic with strong polar side chains such as hydroxyl, carboxyl, and amino groups. In recent times, SS has been widely used in biomaterial applications because of its biocompatibility, biodegradability, and antioxidative and bioactive activities . It is well known that sericin proteins, as the biopolymer and biocompatible materials, have attracted a lot of research interests in fields, such as cosmetics, health care food, and biomaterials . SS can be extracted from silkworm cocoons by easy process such as boiling , also by using high-temperature and high-pressure degumming technique  followed by filtration to remove fibroin fibers . Sericin is gaining wide applications in recent years for the synthesis of MeNPs (Table 1).
14 Synthesis of nanoparticles using sericin
14.1 Silver nanoparticles
Yue et al.  also used sericin as both reducing agent and dispersing agent in the synthesis of AgNPs-sericin (AgNPS-sericin) hybrid colloid, which endowed excellent antibacterial activities, good moisture absorption ability, smooth handle, and wrinkle-resistant properties to improve wearability when embedded on a cotton fabric. The synthesis involved addition of silver nitrate solution to sericin solution (50 g/l), the pH was adjusted to 9.5, and the mixture was placed on the heating magnetic stirrer at 80°C. Color change from pale yellow to brown yellow was observed, and the UV-Vis spectra showed absorption peak at 420 nm. The dynamic light scattering (DLS) showed that the hydrodynamic diameter of AgNPs in the hybrid colloid was approximately 18 nm. Also, the TEM micrograph showed good dispersion of the spherical AgNPs, which had no apparent agglomeration after 1 month, and the XRD indicated four obvious strong peaks in the whole spectrum, which are in accordance with 111, 200, 220, and 311 crystal faces of silver microcrystal . The structure and morphology of the finished cotton fabric with hybrid colloid of AgNPs-sericin was studied. The FTIR spectrum showed peak at 1556 cm−1, which was attributed to the presence of C=N stretching vibration of the imine group in the finished cotton. The XPS measurements revealed binding energy peaks at 368.2 and 374.2 eV, which are in accordance with characteristic of metallic silver. Also, EDX showed strong carbon, oxygen, and gold, silver, and nitrogen peaks as expected. For the antibacterial activities of the finished cotton, initial bacterial reductions of finished cotton fabric by hybrid colloid of Ag NPS-sericin were 99.28% and 99.06% against S. aureus and E. coli, respectively. After approximately 20 washing cycles, it displayed excellent laundering strength at levels higher than 95% for S. aureus and E. coli.
SS was also used as both reducing and stabilizing agent in the synthesis of AgNPs, as reported by Aramwit et al. . Prepared sericin solution was added to the AgNO3 solution (1, 5, and 10 mm) under constant stirring at room temperature overnight. Color change from transparent to yellow was observed, and UV-Vis spectra showed maximum absorption peak at 420 nm. The FTIR spectra of the SS-capped AgNPs showed new functional groups different from the original SS, which included carboxylate (1451, 1404, and 1353 cm−1) and amine salt (830 cm−1). The new absorptions signified the hydrolysis of amide linkage into its basic structural units . The carboxylate groups also acted as a weak reducing agent for the synthesis of AgNPs , , . The TEM micrograph showed that the SS-capped AgNPs were round shaped, with sizes ranging from 46 to 117 nm depending on the concentration of AgNO3. The SS-capped AgNPs showed potent antibacterial activity against various Gram-positive bacteria (B. subtilis, S. aureus, and MRSA) and Gram-negative bacteria (E. coli, P. aeruginosa, and Acinetobacter baumannii).
Bhat et al.  used sericin for the stabilization of AgNPs synthesized by the reduction of silver nitrate with sodium borohydride in an aqueous solution, and color change from transparent to yellow was observed. The UV-Vis spectra revealed an absorption peak of 389 nm (after the synthesis) and 399 nm (after stabilization with sericin). The TEM micrograph showed that the AgNPs were spherical particles with an average diameter of 15 nm. SEM revealed that the AgNPs have fairly uniform size distribution and were fairly monodispersed. The stability of the colloidal nanoparticles was confirmed by zeta potential measurement. The nanoparticles when applied to fabric did not considerably change the color of the fabric and conferred antibacterial activities on the fabric against both Gram-positive and Gram-negative bacteria, namely, S. aureus (ATCC 6538) and Klebsiella pneumoniae (ATCC 4352).
This review has documented the relevance of arthropods in the green synthesis of MeNPs, which traverses the use of metabolites from bees, spider, silk worm, and paper wasps, among others. It is evident that arthropods possess potent biomolecules that are useful for the bioreduction of metal ions to their metallic states. The numerous bioactive molecules shown to be present in arthropods and their metabolites can serve as sources of novel materials for the green synthesis of nanoparticles, for potential applications in nanomedicine. The emerging relevance of arthropods in the green synthesis of nanoparticles is stressed in this review.
Prof. A. Lateef is grateful to the authority of LAUTECH, Ogbomoso, Nigeria, for the provision of some of the facilities used in some works cited in this review.
 Ruppert EE, Fox RS, Barnes RD. Invertebrate Zoology, Seventh ed., Brooks/Cole: Thomson, Belmont, CA, 2004. ISBN: 0-03-025982-7.Search in Google Scholar
 Roy S, Saha S, Pal P. Insect natural product as potential source for alternative medicines – a Review. World Sci. News 2015, 19, 80–94.Search in Google Scholar
 Singh N, Chaudhary A, Abraham J. Susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA) and biological role of silver nanoparticles of honey against MRSA. J. Biol. Active Prod. Nature 2014, 4, 332–342.10.1080/22311866.2014.957097Search in Google Scholar
 Nam KW, Je KH, Lee JH, Han HJ, Lee HJ, Kang SK, Mar W. Inhibition of COX-2 activity and proinflammatory cytokines (TNF-α and IL-1β) production by water soluble sub-fractionated parts from bee (Apis mellifera) venom. Arch. Pharm. Res. 2003, 26, 383–388.10.1007/BF02976695Search in Google Scholar PubMed
 Moon DO, Park SY, Heo MS, Kim KC, Park C, Ko WS. Key regulators in bee venom induced apoptosis are Bcl-2 and caspase-3 in human leukemic U937 cells through down regulation of ERK and Akt. Int. Immunopharmacol. 2006, 6, 1796–1807.10.1016/j.intimp.2006.07.027Search in Google Scholar PubMed
 Liu S, Yu M, He Y, Xiao L, Wang F, Song C, Sun S, Ling C, Xu Z. Melittin prevents liver cancer cells metastasis through inhibition of the Rac-1-dependent pathway. Hepatology 2008, 47, 1964–1973.10.1002/hep.22240Search in Google Scholar PubMed
 Behroozi J, Divsalar A, Saboury AA. Honey bee venom decreases the complications of diabetes by preventing hemoglobin glycation. J. Mol. Liquids 2014, 199, 371–375.10.1016/j.molliq.2014.09.034Search in Google Scholar
 Moon DO, Park SY, Lee KJ, Heo MS, Kim KC, Kim MO, Lee JD, Choi YH, Kim GY. Bee venom and melittin reduce proinflammatory mediators in lipopolysaccharide-stimulated BV2 microglia. Int. Immunopharmacol. 2007, 7, 1092–1101.10.1016/j.intimp.2007.04.005Search in Google Scholar PubMed
 Carpes ST, Begnini R, De Alencar SM. Study of preparations of bee pollen extracts, antioxidant and antibacterial activity. Ciênc. Agrotec. Lavras 2007, 31, 1818–1825.10.1590/S1413-70542007000600032Search in Google Scholar
 Sherman RA, Hall MJR, Thomas S. Medicinal maggots: an ancient remedy for some contemporary afflictions. Ann. Rev. Entomol. 2000, 45, 55–81.10.1146/annurev.ento.45.1.55Search in Google Scholar PubMed
 Chambers L, Woodrow S, Brown AP. Degradation of extra cellular matrix components by defined proteinases from the green bottle larva Lucilia sericata used for the clinical debridement of non-healing wounds. Brit. J. Dermatol. 2003, 148, 14–23.10.1046/j.1365-2133.2003.04935.xSearch in Google Scholar PubMed
 Ratcliffe NA, Mello CB, Garcia ES, Butt TM, Azam-buja P. Insect natural products and processes: new treatments for human disease. Insect Biochem. Mol. Biol. 2011, 41, 747–769.10.1016/j.ibmb.2011.05.007Search in Google Scholar PubMed
 Bohova J, Majtan J, Takac P. Immunomodulatory properties of medicinal maggots Lucilia sericata in wound healing process. Tang Int. J. Genuine Trad. Med. 2012, 2, 1–7.10.5667/tang.2012.0025Search in Google Scholar
 Park SO, Shin JH, Choi WK, Park BS, Oh JS, Jang A. Antibacterial activity of housefly-maggot extracts against MRSA (methicillin-resistant Staphylococcusaureus) and VRE (vancomycin-resistant enterococci). J. Environ. Biol. 2010, 31, 865–871.Search in Google Scholar
 Joyner C, Mills MK, Nayduch D. Pseudomonasaeruginosa in Musca domestica L.: temporospatial examination of bacteria population dynamics and house fly antimicrobial responses. PLoS One 2013, 8, e79224.10.1371/journal.pone.0079224Search in Google Scholar PubMed PubMed Central
 Galvis CEP, Mendez LYV, Kouznetsov VV. Cantharidin-based small molecules as potential therapeutic agents. Chem. Biol. Drug Design 2013, 82, 477–499.10.1111/cbdd.12180Search in Google Scholar PubMed
 Chen YJ, Shieh CJ, Tsai TH, Kuo CD, Ho LT, Liu TY, Liao HF. Inhibitory effect of norcantharidin, a derivative compound from blister beetles on tumor invasion and metastasis CT26 colorectal adenocarcinoma cells. Anticancer Drugs 2005, 16, 293–299.10.1097/00001813-200503000-00008Search in Google Scholar PubMed
 Kok SH, Cheng SJ, Hong CY, Lee JJ, Lin SK, Kuo YS, Chiang CP, Kuo MY. Norcantharidin-induced apoptosis in oral cancer cells is associated with an increase of proapoptotic to antiapoptotic protein ratio. Cancer Lett. 2005, 217, 43–52.10.1016/j.canlet.2004.07.045Search in Google Scholar PubMed
 Fan YZ, Fu JY, Zhao, ZM, Chen CQ. Inhibitory effects of norcantharidin on the growth of human gall bladder carcinoma GBC-SD cells in vitro. Hepatobiliary Pancreat. Dis. Int. 2007, 6, 72–80.Search in Google Scholar
 Hill TA, Stewart SG, Sauer B. Heterocyclic substituted cantharidin and norcantharidin analogues-synthesis, protein phosphatase (1 and 2A) inhibition and anti-cancer activity. Bioorg. Med. Chem. Lett. 2007, 17, 3392–3397.10.1016/j.bmcl.2007.03.093Search in Google Scholar PubMed
 Li W, Xie L, Chen Z. Cantharidin, a potent and selective PP2A inhibitor, induces an oxidative stress-independent growth inhibition of pancreatic cancer cells through G2/M cell cycle arrest and apoptosis. Cancer Sci. 2010, 101, 1226–1233.10.1111/j.1349-7006.2010.01523.xSearch in Google Scholar PubMed
 Wang KR, Zhang W, Yan JX, Li J, Wang R. Antitumor effects, cell selectivity and structure activity relationship of a novel antimicrobial peptide of polybia-MPI. Peptides 2008, 29, 963–968.10.1016/j.peptides.2008.01.015Search in Google Scholar PubMed
 Lateef A, Adelere IA, Gueguim-Kana EB, Asafa TB, Beukes LS. Green synthesis of silver nanoparticles using keratinase obtained from a strain of Bacillus safensis LAU 13. Int. Nano Lett. 2015, 5, 29–35.10.1007/s40089-014-0133-4Search in Google Scholar
 Lateef A, Adeeyo AO. Green synthesis and antibacterial activities of silver nanoparticles using extracellular laccase of Lentinus edodes. Not. Sci. Biol. 2015, 7, 405–411.10.15835/nsb749643Search in Google Scholar
 Lateef A, Azeez MA, Asafa TB, Yekeen TA, Akinboro A, Oladipo IC, Ajetomobi FE, Gueguim-Kana EB, Beukes LS. Cola nitida-mediated biogenic synthesis of silver nanoparticles using seed and seed shell extracts and evaluation of antibacterial activities. BioNanoSci. 2015, 5, 196–205.10.1007/s12668-015-0181-xSearch in Google Scholar
 Lateef A, Azeez MA, Asafa TB, Yekeen TA, Akinboro A, Oladipo IC, Azeez L, Ajibade SE, Ojo SA, Gueguim-Kana EB, Beukes LS. Biogenic synthesis of silver nanoparticles using pod extract of Cola nitida: antibacterial, antioxidant activities and application as additive paint. J. Taibah Univ. Sci. 2016, 10, 551–562.10.1016/j.jtusci.2015.10.010Search in Google Scholar
 Lateef A, Azeez MA, Asafa TB, Yekeen TA, Akinboro A, Oladipo IC, Azeez L, Ojo SA, Gueguim-Kana EB, Beukes LS. Cocoa pod extract-mediated biosynthesis of silver nanoparticles: its antimicrobial, antioxidant and larvicidal activities. J. Nanostruct. Chem. 2016, 6, 159–169.10.1007/s40097-016-0191-4Search in Google Scholar
 Lateef A, Ojo SA, Akinwale AS, Azeez L, Gueguim-Kana EB, Beukes LS. Biogenic synthesis of silver nanoparticles using cell-free extract of Bacillus safensis LAU 13: antimicrobial, free radical scavenging and larvicidal activities. Biologia 2015, 70, 1295–1306.10.1515/biolog-2015-0164Search in Google Scholar
 Lateef A, Ojo SA, Folarin BI, Gueguim-Kana EB, Beukes LS. Kola nut (Cola nitida) mediated synthesis of silver-gold alloy nanoparticles: antifungal, catalytic, larvicidal and thrombolytic applications. J. Cluster Sci. 2016, 27, 1561–1577.10.1007/s10876-016-1019-6Search in Google Scholar
 Ojo SA, Lateef A, Azeez MA, Oladejo SM, Akinwale AS, Asafa TB, Yekeen TA, Akinboro A, Oladipo IC, Gueguim-Kana EB, Beukes LS. Biomedical and catalytic applications of gold and silver-gold alloy nanoparticles biosynthesized using cell-free extract of Bacillus safensis LAU 13: antifungal, dye degradation, anti-coagulant and thrombolytic activities. IEEE Trans. NanoBiosci. 2016. Available from: http://dx.doi.org/10.1109/TNB.2016.2559161.10.1109/TNB.2016.2559161Search in Google Scholar PubMed
 Adelere IA Lateef A. Novel approach to the green synthesis of metallic nanoparticles: the use of agro-wastes, enzymes and pigments. Nanotechnol. Rev. 2016, 5, 567–587.10.1515/ntrev-2016-0024Search in Google Scholar
 Kuppusamy P, Yusoff MM, Maniam GP, Govinda N. Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications – An updated report. Saudi Pharmaceut. J. 2016, 24, 473–484.10.1016/j.jsps.2014.11.013Search in Google Scholar PubMed PubMed Central
 Patel V, Berthold D, Puranik P, Gantar M. Screening of cyanobacteria and microalgae for their ability to synthesize silver nanoparticles with antibacterial activity. Biotechnol. Reports 2015, 5, 112–119.10.1016/j.btre.2014.12.001Search in Google Scholar PubMed PubMed Central
 Wilson EO. The Insect Societies. Harvard University Press: Cambridge, 1971, p. 548, ISBN: 674-45490-1.Search in Google Scholar
 Winston ML. The Biology of the Honey Bee. Harvard University Press; Cambridge, 1987, p. 283, ISBN: 0-674-07409-2.Search in Google Scholar
 Garnery L, Cornuet JM, Solignac M. Evolutionary history of the honey bee Apis mellifera inferred from mitochondrial DNA analysis. Mol. Ecol. 1992, 1, 145–154.10.1111/j.1365-294X.1992.tb00170.xSearch in Google Scholar
 Terrab A, Diez MJ, Heredia FJ. Characterization of moroccan unifloral honeys by their physicochemical characteristics. Food Chem. 2002, 79, 373–379.10.1016/S0308-8146(02)00189-9Search in Google Scholar
 Nanda V, Sarkar BC, Sharma HK, Bawa AS. Physic-chemical properties and estimation of mineral content in honey produced from different plants in Northern India. J. Food Comp. Anal. 2003, 16, 613–619.10.1016/S0889-1575(03)00062-0Search in Google Scholar
 Devillers J, Moriot M, Delegue MHP, Dore JC. Classification of monoflora honeys based on their quality control data. Food Chem. 2004, 86, 305–312.10.1016/j.foodchem.2003.09.029Search in Google Scholar
 Tonks AJ, Dudley E, Porter NG, Parton J, Brazier J, Smith EL, Tonks A. A 5.8-kDa component of manuka honey stimulates immune cells via TLR4. J. Leukocyte Biol. 2007, 82, 1147–1155.10.1189/jlb.1106683Search in Google Scholar PubMed
 Boukraa L, Benbarek H, Moussa A. Synergistic action of starch and honey against Candidaalbicans in correlation with diastase number. Braz. J. Microbiol. 2008, 39, 40–43.10.1590/S1517-83822008000100010Search in Google Scholar
 El-Deeb NM, El-Sherbiny IM, El-Aassara MR, Hafez EE. Novel trend in colon cancer therapy using silver nanoparticles synthesized by honey bee. J. Nanomed. Nanotechnol. 2015, 6, 2.Search in Google Scholar
 Sreelakshmi C, Datta KKR, Yadav JS, Subba Reddy BV. Honey derivatized Au and Ag nanoparticles and evaluation of its antimicrobial activity. J. Nanosci. Nanotechnol. 2011, 11, 6995–7000.10.1166/jnn.2011.4240Search in Google Scholar PubMed
 Obot IB, Umoren SA, Johnson AS. Sunlight-mediated synthesis of silver nanoparticles using honey and its promising anticorrosion potentials for mild steel in acidic environments. J. Mater. Environ. Sci. 2013, 4, 1013–1018.Search in Google Scholar
 Darroudi M, Hoseini SJ, Oskuee RK, Hoseini HA, Gholami L, Gerayli S. Food-directed synthesis of cerium oxide nanoparticles and their neurotoxicity effects. Ceramics Int. 2014, 40, 7425–7430.10.1016/j.ceramint.2013.12.089Search in Google Scholar
 Reddy SM, Datta KKR, Sreelakshmi C, Eswaramoorthy M, Reddy BV. Honey mediated green synthesis of Pd nanoparticles for suzuki coupling and hydrogenation of conjugated olefins. Nanosci. Nanotechnol. Lett. 2012, 4, 420425.10.1166/nnl.2012.1331Search in Google Scholar
 Kothai S, Jayanthi B. Ultrasound Intensified green synthesis of silver nanoparticles using Camellia sinensis extract fortified with lemon and honey. Int. J. Chem. Tech. Res. 2014, 6, 248–253.Search in Google Scholar
 Lateef A, Ojo SA, Azeez MA, Asafa TB, Yekeen TA, Akinboro A, Oladipo IC, Gueguim-Kana EB, Beukes LS. Cobweb as novel biomaterial for the green and eco-friendly synthesis of silver nanoparticles. Appl. Nanosci.2016, 6, 863–874.10.1007/s13204-015-0492-9Search in Google Scholar
 Lateef A, Akande MA, Ojo SA, Folarin BI, Gueguim-Kana EB, Beukes LS. Paper wasp nest-mediated biosynthesis of silver nanoparticles for antimicrobial, catalytic, anti-coagulant and thrombolytic applications. 3Biotech. 2016, 6, 140.Search in Google Scholar
 Wang X, Gao W, Xu S, Xu W. Luminescent fibers: in situ synthesis of silver nanoclusters on silk via ultraviolet light-induced reduction and their antibacterial activity. Chem. Eng. J. 2012, 210, 585–589.10.1016/j.cej.2012.09.034Search in Google Scholar
 Chen W, Wu W, Chen H, Shen Z. Preparation and characterization of noble metal nanocolloids by silk fibroin in situ reduction. Sci. China B. 2003, 46, 330–338.10.1360/03yb0023Search in Google Scholar
 Kharlampieva E, Zimnitsky D, Gupta M, Bergman KN, Kaplan DL, Naik RR, Tsukruk VV. Redox-active ultrathin template of silk fibroin: effect of secondary structure on gold nanoparticle reduction. Chem. Mater. 2009, 21, 2696–2704.10.1021/cm900073tSearch in Google Scholar
 Su H, Han J, Dong Q, Zhang D, Guo Q. In situ synthesis and photoluminescence of QD-CdS on silk fibroin fibers at room temperature. Nanotechnol. 2007, 19, 025601.10.1088/0957-4484/19/02/025601Search in Google Scholar PubMed
 Wongkrongsak S, Tangthong T, Pasanphan W. Electron beam induced water-soluble silkfibroin nanoparticles as a natural antioxidant and reducing agent for a green synthesis of gold nanocolloid. Radiat. Phys. Chem. 2016, 118, 27–34.10.1016/j.radphyschem.2015.03.020Search in Google Scholar
 Kumar RM, Rao BL, Asha S, Narayana B, Byrappa K, Wang Y, Yao D, Sangappa Y. Gamma radiation assisted biosynthesis of silver nanoparticles and their characterization. Adv. Mater. Lett. 2015, 6, 1088–1093.10.5185/amlett.2015.6002Search in Google Scholar
 Das S, Dhar BB. Green synthesis of noble metal nanoparticles using cysteine-modified silk fibroin: catalysis and antibacterial activity. Royal Soc. Chem. Adv. 2014, 4, 46285–46292.10.1039/C4RA06179ASearch in Google Scholar
 Fei X, Jia M, Du X, Yang Y, Zhang Y, Shao Z, Zhao X, Chen X. Green synthesis of silk fibroin-silver nanoparticle composites with effective antibacterial and biofilm-disrupting properties. Biomacromolecules. 2013, 14, 4483–4488.10.1021/bm4014149Search in Google Scholar
 Aramwit P, Bang N, Ratanavaraporn J, Ekgasit S. Green synthesis of silk sericin-capped silver nanoparticles and their potent antibacterial activity. Nanoscale Res. Lett. 2014, 9, 79–86.10.1186/1556-276X-9-79Search in Google Scholar
 Singh M, Singh S, Prasad S, Gambhir IS. Nanotechnology in medicine and antibacterial effect of silver nanoparticles. Digest J. Nanomater. Biostruct. 2008, 3, 115–122.Search in Google Scholar
 Khanna PK, Singh N, Charan S, Subbarao VVVS, Gokhale R, Mulik UP. Synthesis and characterization of Ag/PVA nanocomposite by chemical reduction method. Mater. Chem. Phys. 2005, 93, 117–121.10.1016/j.matchemphys.2005.02.029Search in Google Scholar
 Ahmed M, Karns MM, Goodson J, Rowe S, Hussain SM, Schlager JJ, Hong Y. DNA damage response to different surface chemistry of silver nanoparticles in mammalian cells. Toxicol. Appl. Pharmacol. 2008, 233, 404–410.10.1016/j.taap.2008.09.015Search in Google Scholar
 Sriram MI, Barath S, Kanth M, Kalishwaralal K, Gurunathan S. Antitumor activity of silver nanoparticles in Dalton’s lymphoma ascites tumor model. Int. J. Nanomed. 2010, 5, 753–762.Search in Google Scholar
 Yezhelyev MV, Gao X, Xing Y, Al-Hajj A, Nie S, O’Regan RM. Emerging use of nanoparticles in diagnosis and treatment of breast cancer. Lancet Oncol. 2006, 7, 657–667.10.1016/S1470-2045(06)70793-8Search in Google Scholar
 Wang L, Liu CH, Nemoto Y, Fukata N, Wu KCW, Yamauchi Y. Rapid synthesis of biocompatible gold nanoflowers with tailored surface textures with the assistance of amino acid molecules. RSC Adv. 2012, 2, 4608–4611.10.1039/c2ra20348kSearch in Google Scholar
 Prabhu D, Arulvasu C, Babu G, Manikandan R, Srinivasan P. Biologically synthesized green silver nanoparticles from leaf extract of Vitexnegundo L. induce growth-inhibitory effect on human colon cancer cell line HCT15. ProcessBiochem. 2013, 48, 317–324.10.1016/j.procbio.2012.12.013Search in Google Scholar
 Gmeiner WH, Ghosh S. Nanotechnology for cancer treatment. Nanotechnol.Rev. 2014, 3, 111–122.Search in Google Scholar
 Skrabalak SE, Chen JY, Sun YG, Lu XM, Au L, Cobley CM, Xia YN. Gold nanocages: synthesis, properties, and applications. Acc. Chem. Res. 2008, 41, 1587–1595.10.1021/ar800018vSearch in Google Scholar PubMed PubMed Central
 Sun ST, Wu PY. Competitive surface-enhanced Raman scattering effects in noble metal nanoparticle-decorated graphene sheets. Phys. Chem. Chem. Phys. 2011, 13, 21116–21120.10.1039/c1cp22727kSearch in Google Scholar PubMed
 Au L, Chen YC, Zhou F, Camargo PHC, Lim B, Li ZY, Ginger DS, Xia YN. Synthesis and optical properties of cubic gold nanoframes. Nano Res. 2008, 1, 441–449.10.1007/s12274-008-8046-zSearch in Google Scholar PubMed PubMed Central
 Tang XL, Jiang P, Ge GL, Tsuji M, Xie SS, Guo YJ. Poly(N-vinyl-2-pyrrolidone) (PVP)-capped dendritic gold nanoparticles by a one-step hydrothermal route and their high SERS effect. Langmuir 2008, 24, 1763–1768.10.1021/la703495sSearch in Google Scholar PubMed
 Roslyak O, Aparajita U, Birman JL, Mukamel S. Coherent manipulation of quadrupole biexcitons in cuprous oxide by 2D femtosecond spectroscopy. Phys. Status Solidi B 2012, 249, 435–447.10.1002/pssb.201147402Search in Google Scholar
 Venu R, Ramulu TS, Anandakumar S, Rani VS, Kim CG. Bio-directed synthesis of platinum nanoparticles using aqueous honey solutions and their catalytic applications. Colloids Surf. A. Physicochem. Eng. Aspects. 2011, 384, 733–738.10.1016/j.colsurfa.2011.05.045Search in Google Scholar
 Glime JM. Arthropods: arachnida-spider biology. In Bryophyte Ecology, vol. 2, Glime JM, Ed., Bryological 7-2-1 Interaction. E-book sponsored by Michigan Technological University and the International Association of Bryologists: Houghton, Michigan, USA, 2013.Search in Google Scholar
 Denver Museum of Nature and Science. Spider Biology. Available from: http://www.dmns.org/colorado-spider-survey/spider-biology/, 2015, accessed on 1 March, 2015.Search in Google Scholar
 Blackledge TA, Kuntner M, Agnarsson I. The form and function of spider orb webs: evolution from silk to ecosystems. Adv. Insect Physiol. 2011, 41, 175–262.10.1016/B978-0-12-415919-8.00004-5Search in Google Scholar
 Simmons AH, Michal CA, Jelinski LW. Molecular orientation and two-component nature of the crystalline fraction of spider dragline silk. Science 1996, 271, 84–87.10.1126/science.271.5245.84Search in Google Scholar
 Papadopoulos P, Ene R, Weidner I, Kremer F. Similarities in the structural organization of major and minor ampullae spider silk. Macromol. Rapid Comm. 2009, 30, 851–857.10.1002/marc.200900018Search in Google Scholar
 Heimer S. Wunderbare Welt der Spinnen: Urania: Leipzig, Germany, 1988.Search in Google Scholar
 Chakraborty DS. Antibacterial activities of cobweb protein. 19th European Congress of Clinical Microbiology and Infectious Diseases: Helsinki, Finland, 2009, pp. 16–19Search in Google Scholar
 Gomes SC, Leonor IB, Mano JF, Reis RL, Kaplan DL. Functionalized silk biomaterials for bone regeneration. Semana de Engenharia. Guimarães, 11 a 15 de Outubro, 2010), pp. 1–2.Search in Google Scholar
 Higgins LE, Townley MA, Tillinghast EK, Rankin MA. Variation in the chemical composition of orb webs built by the spider Nephila clavipes (Araneae, Tetragnathidae). J. Arachnol. 2001, 29, 82–94.10.1636/0161-8202(2001)029[0082:VITCCO]2.0.CO;2Search in Google Scholar
 Porter D, Vollrath F, Shao Z. Predicting the mechanical properties of spider silk as a model nanostructural polymer. Eur. Phys. J.E. Soft Matter. 2005, 16, 199–206.10.1140/epje/e2005-00021-2Search in Google Scholar
 Jackso, RR. Effects of d-amphetamine sulphate and diazepam on thread connection fine structure in a spider’s web. J. Arachnol. 1974, 2, 37–41.Search in Google Scholar
 Allmeling C, Jokuzies A, Reimers K, Kall S, Vogt PM. Use of spider silk fibers as an innovative material in a biocompatible artificial nerve conduit. J. Cellul. Mol. Med. 2006, 10, 770–777.10.1111/j.1582-4934.2006.tb00436.xSearch in Google Scholar
 Gellynck K. Coconzidje en spirnragweefsel engineering: cocoon and cobwebs in Tissue Engineering. Doctoral Thesis in Biotechnology submitted to Ghent University: Belgium, 2006, pp. 220.Search in Google Scholar
 Roozbahani H, Asmar M, Ghaemi N, Issazadeh K. Evaluation of antimicrobial activity of spider silk Pholcus phalangioides against two bacterial pathogens in food borne. Int. J. Adv. Biol. Biomed. Res. 2014, 2, 2197–2199.Search in Google Scholar
 Ayedun H, Adewole A, Osinfade BG, Ogunlusi RO, Umar BF, Rabiu SA. The use of spider webs for environmental determination of suspended trace metals in industrial and residential areas. J. Environ. Chem. Ecotoxicol. 2013, 5, 21–25.Search in Google Scholar
 Maloney D, Drummond FA, Alford R. Spider predation in agroecosystems: can spiders effectively control pest populations. Tech. Bull. Univ. Maine. 2003, 190, 32, ISSN: 1070.1524. Maine Agricultural and Forest Experiment Station, The University of Maine.Search in Google Scholar
 Andrade E, Villanova F, Borra P, Leite K, Troncone L, Cortez I, Messina L, Paranhos M, Claro J, Srougi M. Penile erection induced in vivo by a purified toxin from the Brazilian spider Phoneutria nigriventer. Brit. J. Urol. Int. 2008, 102, 835–837.10.1111/j.1464-410X.2008.07762.xSearch in Google Scholar PubMed
 West-Eberhard MJ. Polistes passions. Ann Zool Fenn. 2006, 43, 387–389.Search in Google Scholar
 Sinzato DM, Andrade FR, De Souza AR, Del-Claro K, Prezoto F. Colony cycle, foundation strategy and nesting biology of a Neotropical paper wasp. Rev. Chil. Hist. Nat. 2011, 84, 357–363.10.4067/S0716-078X2011000300004Search in Google Scholar
 Nguyen LTP, Kojima JI. Distribution and nests of paper wasps of Polistes (Polistella) in northeastern Vietnam, with description of a new species (Hymenoptera, Vespidae, Polistinae). ZooKeys 2014, 368, 45.10.3897/zookeys.368.6426Search in Google Scholar PubMed PubMed Central
 Wenzel JW. Learning, behaviour programs, and higher-level rules in the nest construction of Polistes. In: Natural History and Evolution of Paper-Wasp, Turillazzi, S and West-Eberhard, MJ, Eds., Oxford University Press: Oxford, 1996, 58–74.Search in Google Scholar
 Clapperton BK, Lo PL. Nesting biology of Asian paper wasps Polistes chinensis antennalis Perez, and Australian paper wasps Polistes humilis (Fabricius) (Hymenoptera, Vespidae) in northern New Zealand. N. Z. J. Zool. 2000, 2, 189–195.10.1080/03014223.2000.9518225Search in Google Scholar
 Evans HE, West-Eberhard MJ. The Wasps. University of Michigan Press: Ann Arbor, 1970, p. 265.Search in Google Scholar
 Singer TL, Espelie KE, Himmelsbach DS. Ultrastructural and chemical examination of paper and pedicel from laboratory and field nests of the social wasp Polistesmetricus Say. J. Chem. Ecol. 1992, 18, 77–86.10.1007/BF00997166Search in Google Scholar PubMed
 Kudô K, Hozumi S, Yamamoto H, Yamane S. Amino acid composition of the protein in preemergence nests of Polistes (Polistes) riparius, and its similarity to the consubgeneric wasp, P. (P.) chinensis (Hymenoptera: Vespidae). J. Ethol. 2000, 18, 75–77.10.1007/s101640070003Search in Google Scholar
 Kudô K, Yamamoto H, Yamane S. Amino acid composition of the protein in pre-emergence nests of a paper wasp, Polisteschinensis (Hymenoptera, Vespidae). Insectes Sociaux. 2000, 47, 371–375.10.1007/PL00001733Search in Google Scholar
 Turillazzi S, Mastrobuoni G, Dani FR, Moneti G, Pieraccini G, la Marca G, Bartolucci G, Perito B, Lambardi D, Cavallini V, Dapporto L. Dominulin A and B: two new antibacterial peptides identified on the cuticle and in the venom of the social paper wasp Polistesdominulus using MALDI-TOF, MALDI-TOF/TOF, and ESI-ion trap. J. Am. Soc. Mass Spectrometr. 2006, 17, 376–383.10.1016/j.jasms.2005.11.017Search in Google Scholar PubMed
 Altman GH, Diaz F, Jakuba C, Calabro T, Horan RL, Chen J, Lu H, Richmond J, Kaplan DL. Silk-based biomaterials. Biomaterials 2003, 24, 401–416.10.1016/S0142-9612(02)00353-8Search in Google Scholar
 Prommuak C, De-Eknamkul W, Shotipruk A. Extraction of flavonoids and carotenoids from Thai silk waste and antioxidant activity of extracts. Separat. Purif. Technol. 2008, 62, 444–448.10.1016/j.seppur.2008.02.020Search in Google Scholar
 Kojthung A, Meesilpa P, Sudatis B, Treeratanapiboon L, Udomsangpetch R, Oonkhanond B. Effects of gamma radiation on biodegradation of Bombyxmori silk fibroin. Int. Biodeterior. Biodegr. 2008, 62, 487–490.10.1016/j.ibiod.2007.12.012Search in Google Scholar
 Bhat PN, Nivedita S, Roy S. Use of Sericin of Bombyx mori in the synthesis of silver nanoparticles, their characterization and application. Ind. J. Fibre Textile Res. 2011, 36, 168–171.Search in Google Scholar
 Gotoh K, Kanamoto T, Tamada Y. Sulfated fibroin, a novel sulfated peptide derived from silk, inhibits human immunodeficiency virus replication in vitro. Biosci. Biotechnol. Biochem. 2000, 64, 1664–1670.10.1271/bbb.64.1664Search in Google Scholar
 Min S, Hu Z. Research on drug absorbing and releasing functions of fibroin and its control. Chin. J. Biomed. Eng. 2002, 21, 361–366.Search in Google Scholar
 Sofia S, McCarthy MB, Gronowicz G, Kaplan DL. Functionalized silk-based biomaterials for bone formation. J. Biomed. Mater. Res. 2001, 54, 139–148.10.1002/1097-4636(200101)54:1<139::AID-JBM17>3.0.CO;2-7Search in Google Scholar
 Xing T, Hu W, Li S, Chen G. Preparation, structure and properties of multifunctional silk via ATRP method. Appl. Surf. Sci. 2012, 258, 3208–3213.10.1016/j.apsusc.2011.11.065Search in Google Scholar
 Ude AU, Eshkoor RA, Zulkifili R, Ariffin AK, Dzuraidah AW, Azhari CH. Bombyx mori silk fibre and its composite: a review of contemporary developments. Mater. Design 2014, 57, 298–305.10.1016/j.matdes.2013.12.052Search in Google Scholar
 She Z, Huang Z, Zhang B, Jin C, Feng Q, Xu Y. Preparation and in vitro degradation of porous three-dimensional silkfibroin/chitosan scaffold. Polym. Degradat. Stability 2008, 93, 1316–1322.10.1016/j.polymdegradstab.2008.04.001Search in Google Scholar
 Ali MM, Arumugam SB. Effect of crude extract of Bombyx mori coccoons in hyperlipidemia and atherosclerosis. J. Ayurveda Integrat. Med. 2011, 2, 72–78.10.4103/0975-9476.82527Search in Google Scholar
 Zhang X, Geng X, Jiang H, Li J, Huang J. Synthesis and characteristics of chitin and chitosan with the (2-hydroxy-3-trimethylammonium) propyl functionality, and evaluation of their antioxidant activity in vitro. Carbohydr. Polym. 2012, 89, 486–491.10.1016/j.carbpol.2012.03.032Search in Google Scholar
 Moure A, Cruz JM, Franco D, Domínguez JM, Sineiro J, Domínguez H, Núñez MJ, Parajó JC. Natural antioxidants from residual sources. Food Chem. 2001, 72, 145–171.10.1016/S0308-8146(00)00223-5Search in Google Scholar
 Zhou Y, Chen W, Chujo Y. Preparation of a novel core-shell nanostructured gold colloid-silk fibroin bioconjugate by the protein in situ redox technique at room temperature. Chem. Comm. 2001, 23, 2518–2519.10.1039/b108013jSearch in Google Scholar PubMed
 Shengjie X, Liu Y, Peiyi W. One-pot, green, rapid synthesis of flowerlike gold nanoparticles/reduced graphene oxide composite with regenerated silk fibroin as efficient oxygen reduction electrocatalysts. ACS Appl. Mater. Interf. 2013, 5, 654–662.10.1021/am302076xSearch in Google Scholar PubMed
 Wang X, Yucel T, Lu Q, Hu X, Kaplan DL. Silk nanospheres and microspheres from Silk/PVA blendfilms for drug delivery. Biomaterials 2010, 31, 1025–1035.10.1016/j.biomaterials.2009.11.002Search in Google Scholar PubMed PubMed Central
 Ritchie CM, Johnsen KR, Kiser JR, Antoku Y, Dickson RM, Petty JT. Ag nanocluster formation using a cytosine oligonucleotide template. J. Phys. Chem. C. 2007. 111, 175–181.10.1021/jp0648487Search in Google Scholar PubMed PubMed Central
 Jin R, Cao Y, Hao E, Metraux GS, Schatz GC, Mirkin CA. Controlling anisotropic nanoparticle growth through plasmon excitation. Nature 2003, 425, 487–490.10.1038/nature02020Search in Google Scholar PubMed
 Jasuja K, Berry V. Implantation and growth of dendritic gold nanostructures on graphene derivatives: electrical property tailoring and Raman enhancement. ACS Nano 2009, 3, 2358–2366.10.1021/nn900504vSearch in Google Scholar PubMed
 Izumrudov V, Kharlampieva E, Sukhishvili SA. Multilayers of a globular protein and a weak polyacid: role of polyacid ionization in growth and decomposition in salt solutions. Biomacromolecules 2005, 6, 1782–1788.10.1021/bm050096vSearch in Google Scholar PubMed
 Wang CW, Moffitt MG. Surface-tunable photoluminescence from block-copolymer stabilized cadmium sulfide quantum dots. Langmuir 2004, 20, 11784–11796.10.1021/la048390gSearch in Google Scholar PubMed
 Yue X, Lin H, Yan T, Zhang D, Lin H, Chen Y. Synthesis of silver nanoparticles with sericin and functional finishing to cotton fabrics. Fibers Polym. 2014, 15, 716–722.10.1007/s12221-014-0716-8Search in Google Scholar
 Lee K, Kweon H, Yeo JH, Woo SO, Lee YW, Cho CS, Kim KH, Park YH. Effect of methyl alcohol on the morphology and conformational characteristics of silk sericin. Int. J. Biol. Macromol. 2003, 33, 75–80.10.1016/S0141-8130(03)00069-2Search in Google Scholar
 Vigneshwaran N, Nachane RP, Balasubramanya RH, Varadarajan PV. A novel one-pot ‘green’ synthesis of stable silver nanoparticles using soluble starch. Carbohydr. Res. 2006, 341, 2012–2018.10.1016/j.carres.2006.04.042Search in Google Scholar PubMed
 Socrates G. Infrared and Raman Characteristic Group Frequencies: Table and Chart. Chichester: Wiley, 2000.Search in Google Scholar
 Dong Q, Su H, Zhang D. In situ depositing silver nanoclusters on silk fibroin fibers supports by a novel biotemplate redox technique at room temperature. J. Phys. Chem. 2005, 109, 17429–17434.10.1021/jp052826zSearch in Google Scholar PubMed
 Rafey A, Shrivastavaa, KBL, Iqbal SA, Khan Z. Growth of Ag-nanoparticles using aspartic acid in aqueous solutions. J. Colloid Interf. Sci. 2011, 354, 190–195.10.1016/j.jcis.2010.10.046Search in Google Scholar PubMed
 Song J, Roh J, Lee I, Jang J. Low temperature aqueous phase synthesis of silver/silver chloride plasmonic nanoparticles as visible light photocatalysts. Dalton Trans. 2013, 42, 13897–13904.10.1039/c3dt51343bSearch in Google Scholar PubMed
©2016 Walter de Gruyter GmbH, Berlin/Boston
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.