POTENTIOMETRIC MICROSENSORS

Chemical microsensors are a growing area of analytical microinstrumentation. The miniaturization resulting from combination of traditional electrochemical and integrated circuit fabrication techniques not only has obvious practical advantages, e.g., size, sample volume speed of response, etc., but also opens some fundamentally new possibilities. Thus, the use of pHsensitive insulators is possible only in ISFETs. The troublesome interference from buffer capacity in pHbased enzyme sensors may be mitigated by the internal generation and control of hydrogen ions inside the enzyme- containing layer. This can be conveniently done in a microfabricated enzyme electrode. Finally, a whole new class of solid-state potentiometric microsensors based on chemical modulation of the electron work function can be built around the insulated gate field effect transistor. © 1990, American Chemical Society. All rights reserved.