The Suslick Research Group at the University of Illinois Urbana-Champaign created an extremely sensitive and portable “optoelectronic nose” used in the detection of toxic gases and other substances [1-4]. It is also developing cumulative colorimetric sensor arrays which are inexpensive, and cross-reactive, using a wide range of chemical interactions with analytes (i.e., not just physical adsorption): an optical analog of mammalian olfaction. A composite response to volatiles in the environment can be measured quantitatively by digitally monitoring the change in color of each spot on an easily printed array (Fig. 1). These new colorimetric sensor arrays are 100s of times more sensitive than conventional passive monitoring diffusion tubes. The use of a disposable array permits the use of stronger chemical interactions, which dramatically improves both sensitivity and specificity compared to any prior e-nose technology. Importantly the sensor array has been specifically engineering to be insensitive to humidity changes. The sensor array has been successfully used for detection of toxic gases at ppb levels, for identification of cultured pathogenic bacteria (and their antibiotic resistance), and for discovery of explosives including peroxide based compounds such as TATP (triacetone triperoxide, the explosive used in the recent terrorist bombings in Paris and Brussels).
A compact reader (the size of a double-deck of cards) for these arrays is available for active sensing and uses a color contact image sensor (a line imaging unit used for portable business card and paper scanners). In addition, cell phone camera imaging was used to monitor artwork after passive exposure in situ during a Disney Animation Research Library exhibition, “Drawn from Life: the Art of Disney Animation Studios”, in Beijing. Sensor arrays monitoring pollutant exposure were placed in the exterior and interior environments of passe partout frames during the course of the exhibition and inside shipping crates during transport (Fig. 2). This work, a collaboration between the Getty Conservation Institute (GCI) and the University of Illinois, was previously supported by a National Science Foundation grant.
Fig. 1. Color difference maps of the colorimetric sensor array are “molecular fingerprints” and quantitatively identify pollutants, even at part per billion concentrations.
Fig. 2. Placement of colorimetric sensor arrays on the back side of passe partout frames for the 2015 “Drawn from Life”, the first traveling exhibit from the Walt Disney Corp. to China; artwork © Disney.
References
1. Rakow, N. A.; Suslick, K. S. “A Colorimetric Sensor Array for Odor Visualization” Nature, 2000, 406: 710-714. 10.1038/35021028Search in Google Scholar PubMed
2. Lim, S. H.; Feng, L.; Kemling, J. W.; Musto, C. J.; Suslick, K. S. “An Optoelectronic Nose for Detection of Toxic Gases” Nature Chemistry, 2009, 1:562-567. 10.1038/nchem.360Search in Google Scholar PubMed PubMed Central
3. Askim, J. R.; Li, Z.; LaGasse, M. K.; Rankin, J. M.; Suslick, K. S. “An optoelectronic nose for identification of explosives” Chem. Sci., 2016, 7:199-206. 10.1039/C5SC02632FSearch in Google Scholar PubMed PubMed Central
4. Askim, J. R.; Mahmoudi, M.; Suslick, K. S. “Optical sensor arrays for chemical sensing: the optoelectronic nose” Chem. Soc. Rev. 2013, 42:8649 - 8682.10.1039/c3cs60179jSearch in Google Scholar PubMed
©2016 by Walter de Gruyter Berlin/Boston
