Towards a biomimetic smell sensor

Three of our five senses, namely, seeing, hearing, and touching, have been commercialized in small powerful sensors and are present in almost every electronic device (smartphone etc). Odor and taste, due to their fundamentally different detection mechanism, represent an extreme challenge for the technical implementation. In contrast to readily attainable mechano- or photoreceptors, chemoreceptors which are capable of translating a chemical-biological signal into an electronic one and are a prerequisite for odor and taste sensors. In this presentation we will highlight our research efforts using three different biomimetic approaches (Figure 1): A) an array of ultra-low cost chemiresistors based on conductive polymers1 is used to mimic the combinatorial code of the olfactory process. The conductive polymers respond to odorants with changes in their electronic performance and by tuning their chemical side groups they can be more specifically tailored to different chemical classes. B) In order to improve the specificity of the sensors we also use odor-binding proteins - derived from insects - as a biological recognition unit for fragrances.2 The binding of an odorant to an odor-binding protein alters its three-dimensional structure. This conformational change is then converted into an electronic signal because the structural variation also causes a change in the electronic properties of the underlying transistor material. C) Finally, we present our newest efforts in using artificial membrane structures3 (tethered lipid membranes) to better mimic the cell membranes which, host the olfactory receptors in the real world and which are essential to take advantage of the signal amplification process in olfaction. The aim of our research is to produce, characterize, compare and benchmark these systems with other methods, tools and finally mother nature itself (electroantennography) to create a better understanding of the olfactory process. Figure 1: Schematic illustration of our biomimetic smell sensor efforts. Left: Schematic of a field-effect transistor endowed with odorant binding proteins; Middle: Logo: illustration of the use of insect odorant binding proteins for smell sensing; Right: difference between human- and electronic nose concepts References [1] Yang, S.; Bintinger, J.; Park, S.; Jain, S.; Alexandrou, K.; Fruhmann, P.; Besar, K.; Katz, H.; Kymissis, I. IEEE Sens. Lett. 2017, PP (99), 1-1 [2] Larisika, M.; Kotlowski, C.; Steininger, C.; Mastrogiacomo, R.; Pelosi, P.; Schütz, S.; Peteu, S. F.; Kleber, C.; Reiner-Rozman, C.; Nowak, C.; Knoll, W.; Angew. Chem. 2015, 127 (45), 13443-13446.. [3] Andersson, J.; Köper, I. Membranes 2016, 6 (2).