Abstract
Three new ISFET devices (ion-selective field effect transistor) based on polymeric selective membranes sensitive to cationic surfactants have been fabricated and characterised. These new sensors use a PVC-sebacate matrix incorporating benzyldimethyl-hexadecylammonium reineckate, dodecyltrimethyl-ammonium reineckate and hexadecylpyridinium phosphotungstate, respectively, as exchanger.
A complete electroanalytical characterisation of new cationic ISFETs has been performed and the analytical results compared with those obtained using other sensors such as ISEs equipped with the same exchanger or using a biosensor responsive to cationic and anionic surfactants. Determinations of cationic surfactants in authentic aqueous matrices of environmental interest have been carried out using the new sensor with the best performance. Furthermore, the critical micellar concentration (CMC) of some cationic surfactants has also been evaluated.