Strategic issues in reliable sensing.
Amperometric enzyme biosensors must possess two important characteristics if they are to be successfully utilised as reliable monitoring devices. They must exhibit linearity over concentrations relevant to the target analyte, and they must avoid contamination, adverse reactions with the sample matrix response to interferents that react directly at the polarised working electrode surface. Covering polymeric membranes have provided a useful route to overcoming these problems. This report summarises successful modulation of membrane bulk as well as surface properties using surfactant-loaded diffusion limiting PVC and phenolic membranes, and the possible exploitation of direct response conducting poly (pyrrole) membrane loaded with affinity molecules through impedance spectroscopy.