Ak. Covington, TERMINOLOGY AND CONVENTIONS FOR MICROELECTRONIC ION-SELECTIVE FIELD-EFFECT TRANSISTOR DEVICES IN ELECTROCHEMISTRY, Pure and applied chemistry, 66(3), 1994, pp. 565-569
In anticipation of the widespread use of Ion-Selective Field Effect Tr
ansistors (ISFETs) in electrochemistry and analytical chemistry it is
appropriate to make recommendations about terminology and presentation
of results. The terms gate voltage, drain current and gate bias poten
tial are defined and experimental techniques for measurements with ISF
ETs are summarized. The output signal is usually a potential differenc
e whose magnitude varies with change in logarithm of sensed ion activi
ty or concentration in the same way (but not in sign) as the correspon
ding ion-selective electrode (ISE). It is proposed that the graphical
representation of results should be in accordance with previously made
recommendations for ISEs, that is, that the output potential differen
ce be plotted so that variation with increase of logarithm of activity
or concentration has a positive slope for cation-responsive devices a
nd a negative slope for anion-responsive devices.