Abstract
For sensing a variety of odorants, some odorant sensors based on metal-oxide semiconductors or quartz crystal microbalances have been put to practical uses. However, the performances of these sensors are inferior to the olfaction of living organisms in terms of sensitivity and selectivity. Living organisms, especially insects, use numerous olfactory sensory neurons, which express different odorant receptors, to sensitively detect the environmental odorants in real time. Therefore, by focusing on the olfactory mechanisms of insects, we have developed two odorant sensors that consist of a microchannel chip and living cells expressing insect odorant receptors. One sensor, in which Xenopus laevis oocytes were incorporated, exhibited a high odorant detection sensitivity of a few ppb levels and a good portability capable of being integrated into a robot. The other sensor based on fluorescent imaging of cultured insect cells, Sf21 cells, was able to sensitively and selectively detect odorants by visualization of their fluorescent over a long period of time. These results show that our proposed sensor devices provide an innovative platform to develop odorant sensors for detecting various types of odorants with high performances.
