The development of novel odorant sensors based on insect olfaction

Abstract

Existing odorant sensors are mainly fabricated based on metal-oxide semiconductor devices or quartz crystal microbalances. These sensors have been used for practical odorant-detection applications, because of their long-term stability and physicochemical principles. However, the performance of these sensors is still inferior to that of the olfactory systems of living organisms in terms of selectivity, sensitivity, and response time. Living organisms, especially insects, are equipped with sophisticated molecular mechanisms, starting with odorant receptors, which enable sensitive real-time detection of various types of odorants present in the environment.

Therefore, focusing on the olfactory mechanisms of insects, we have developed two odorant sensor elements based on cultured cell lines and transgenic silkmoths, in other words, insect odorant receptor genes are inserted into their genome with genetic engineering techniques. One sensor element using an insect cultured cell line, the Sf21 cell line, is able to sensitively detect odorants by increasing its fluorescent intensity over at least 2 months. The other sensor element using the transgenic silkmoth, Bombyx mori, not only has sensitive odorant detection but also odor source orientation. These results show that our proposed sensor elements can be applied to detect various kinds of odorants with high sensitivity and selectivity, and provide an innovative platform to develop odorant sensors with high performance.