Chemically sensitive field-effect transistor to detect organophosphorous compounds and pesticides

A critical assessment is made concerning the application of a chemically sensitive field-effect transistor (CHEMFET) to detect organophosphorous compounds and pesticides in the ambient environment at the ppb concentration level. A performance analysis of the four types of CHEMFET structures -- enzyme-coupled, galvanostatic, catalytic, and work-function -- is presented. The integration of chemically sensitive polymers with the field-effect transistor structure is addressed. The focus of the assessment deals with practical performance criteria such as sensitivity, response time, reversibility, shelf-life, operational life, and lifetime.