An odorless and colorless chemical-code system using biochemical sniffers

A novel colorless and odorless chemical code system was constructed with gas-phase biosensors(bio-sniffers). Three volatile chemicals, hydrogen peroxide (H2O2), lactate and choline vapors were used for chemical code. The bio-sniffer devices for these 3 chemicals were constructed by applying catalase, lactate oxidase and choline oxidase immobilized membrane to a Clark-type oxygen electrode, respectively. Each bio-sniffer showed high selectivity for their chemical vapor due to the substrate specificity of the enzyme without crosstalk error. Thus, a 3-bit (8-channel) chemical code was successfully recognized and distinguished by 3 kinds of the bio-sniffers.