efficiency of DNAzyme to enhance the sensing signal. In this review, we will discuss recent advances in DNAzyme conjugated nanomaterials as sensing platforms for biosensing applications. For a brief demonstration, nanomaterials including gold nanoparticles, carbon nanomaterials, magnetic nanoparticles and semiconductor quantum dots were taken as examples. DNAzyme conjugated nanomaterials in biosensing DNAzyme conjugated gold nanoparticles in biosensing There are some unique properties for gold nanoparticles (AuNPs), such as optical properties, distance-dependent surface
traditional materials, research in metamaterials has intensified in the past decade. Metamaterials are a class of engineered materials that do not exist in nature and exhibit exotic and unusual electromagnetic properties that make them attractive for applications in bioengineering and biosensing [ 56 ], [ 57 ], [ 58 ]. In particular, metamaterials that show hyperbolic dispersion such as 3D hyperbolic metamaterials (HMMs) and 2D hyperbolic metasurfaces (HMs) have shown extreme sensitivity for low concentrations of smaller bioanalytes [ 59 ], [ 60 ], [ 61 ], [ 62 ]. HMMs are
sensor performance is determined not only by the sensitivity of the plasmonic nanostructure, but also depends heavily on the biorecognition elements employed. Therefore, rather than narrowly focusing on the physics of nanoplasmonic sensors, this review will provide an integrated view on refractometric SPR biosensing technologies, including plasmon resonances in nanostructures, biorecognition elements and surface modification strategies, mass transport effects, optical instrumentation and noise reduction techniques, and various performance metrics. Some emphasis will
1 Introduction Optical fiber gratings (OFGs) are being increasingly proposed as optical platforms for label-free biosensing as promising alternatives to the most traditional ones based on surface plasmon resonance (SPR) or on interferometric configurations. OFGs have been demonstrated to offer comparable performance with respect to more classical optical platforms, but with the intrinsic advantages of the optical fibers, such as high compactness and potential miniaturization, as well as high compatibility with optoelectronic devices (both sources and detectors
detection. In view of the limitations of CLIA and ELISA, label-free biosensing by plasmonics shows promising potential for detecting CEA levels [ 9 ], [ 10 ]. So far, commercial plasmonic sensor technology has been established on the basis of a prism configuration [ 11 ], but it is still cumbersome, inflexible, and uneconomic in the age of Internet of things [ 12 ]. Therefore, in view of future commercialization, exploiting a low-cost portable sensing system with a simple, reliable, and highly sensitive scheme is still a great challenge in the plasmonic biosensing
-cost, high quality, high yield Time-consuming, moderate scalability FET interconnects,NEMs composite s [ 45 ], [ 46 ] 7. Arc discharge of graphite Nanosheets (100s of nm to >10 μ m ) High crystallinity, high purity, low cost, large-scale production Non-uniform, impure Novel composite materials [ 32 ], [ 33 ] 8. Carbon dioxide reduction Few layer graphene High yield, cost effective Delicate, time consuming Nano electronics, sensors, composites [ 47 ] 2.1 Significance of graphene for electrochemical biosensing Graphene and sensors are a natural combination, as graphene
interfaces switchable by physical and chemical
signals for biosensing, biofuel, and biocomputing applications,
Anal. Bioanal. Chem., 2013, 405, 3659-3672.
 Privman M., Tam T.K., Bocharova V., Halámek J., Wang J., and
Katz E., Responsive interface switchable by logically processed
physiological signals – Towards “smart” actuators for signal
amplification and drug delivery, ACS Appl. Mater. Interfaces,
2011, 3, 1620–1623.
 Wang X., Zhou J., Tam T.K., Katz E., and Pita M., Switchable
electrode controlled by Boolean logic gates using enzymes as
AgNPs could enhance the signal by 10-fold compared with AuNPs for the same amount of targets, and a detection limit of 100 pM could be easily achieved using AgNP-based MBs. However, the detection performance strongly depended on the particle size of AgNPs. Quantum dots (QDs) are another nanomaterial superior to traditional organic dyes due to their exceptional optical properties, such as broad absorption spectra, narrow emission spectra, high quantum yield, and excellent photostability. Attempts were made to explore the possibility to use QD-based MBs for biosensing
 B. Liedberg, C. Nylander, and I. Lundström, “Biosensing with
surface plasmon resonance–how it all started.,” Biosens. Bioelectron.
10 (8), 1995, pp. i–ix.
 J. Homola, S. S. Yee, and G. Gauglitz, “Surface plasmon resonance
sensors: review,” Sensors Actuators B Chem. 54 (1–2),
1999, pp. 3–15.
 X. Wang, S. Zhan, Z. Huang, and X. Hong, “Review: Advances
and Applications of Surface Plasmon Resonance Biosensing Instrumentation,”
Instrum. Sci. Technol. 41(6), 2013, 574–607.
 J. Dostálek, H. Vaisocherová, and J. Homola, “Multichannel surface