Detection of Explosives Using Field-Effect Transistors

The gate surfaces of ion-sensitive field-effect transistor (ISFET) devices were functionalized with the pi-donor units, 6-hydroxydopamine (1) or 4-aminothiophenol (2). Concentration of trinitrotoluene, TNT, on the gate via pi-donor-acceptor interactions yields charge-transfer complexes that alter the gate potential. This enables the label-free analysis of TNT with a detection limit corresponding to 1 x 10(-7) M.