Functionalized polysiloxanes can be used as sensing membranes in ion-s
ensitive field effect transistors (ISFETs). A new and reproducible rou
te for obtaining well-defined polysiloxane copolymers-the anionic copo
lymerization of cyclotetrasiloxanes with different side groups (one of
which is shown in the Figure)-is reported and the characterization an
d use of the copolymers in CHEMFETS described.