“…Since 1975, a significant amount of research has been directed toward finding the best materials for the gate to give better sensitivity and selectivity for a variety of analytes. Several other variations on MOSFETs have been developed, such as open gate field effect transistors (OGFET), ion sensitive field effect transistors (ISFET) (which have an electrolyte solution as the conducting layer), and CHEMFETs (which are ISFETs coated with an organic membrane). , Although many variations on MOSFETs have been developed, the GASFET seems to be the only type that has been fabricated into cross-reactive arrays.…”