Coupling of insect antennae to field-effect transistors for biochemical sensing

A bioelectronic interface based on the coupling of an intact insect antenna to a field-e effct transistor (FET) has been realised in a whole-beetle BioFET (Biologically sensitive FET) and an isolated-antenna BioFET configuration. The intrinsic BioFET characteristics, such as current-voltage curves, transconductance and signal-to-noise ratio clearly depend on the chip layout. Therefore, the experiments were performed with three di erent gate geometries: linear shape (5 um x 100 um), U shape (5 um x 1000 um) and meander shape (10 um x 6000 um). The BioFET allows the determination of the `green-leaf odour' Z-3-hexen-l-ol down to the low ppb concentration range. Thus, the detection of plant damages is possible with this novel kind of biosensor.