Insect olfactory receptors as essential detectors for volatile chemicals in biomimetic odorant sensors

Insect has a highly sensitive and accurate discrimination capacity for sensing odorants in the environment, though its olfactory system is much simpler than mammalian's. Insect olfactory receptor (OR) proteins play key roles in odor detection and discrimination. Unlike the complex olfactory signaling in mammalian, the insect ORs can be directly gated by odorants, and can function without the co-expression of downstream signaling molecules. Therefore, insect ORS hold great promise as detectors in a biosensor for detection of volatile chemicals. Several important OR genes in Drosophila, which respond to explosive vapor or related precursors such as PETN and 2-ehtyl-hexanol, have been reported. The present work screened and selected OR genes which are sensitive to explosive vapor and related precursors by calcium imaging and electrophysiological techniques. Furthermore, a biomimetic odorant sensor which co-expresses these OR genes and a companion receptor Or83b in living cells is being constructed, in order to classify unknown volatile chemicals and detect specific types of illicit substances. This study provides an alternative way for the construction of odorant sensors, comparing to the traditional electronic noses which are not as sensitive and accurate as natural noses, and would promote the development and application of biomimetic odorant sensors in a range of applications such as security and environmental monitoring.