Electropolymerized molecularly imprinted polymers as receptor layers in a capacitive chemical sensors

The first application of molecularly imprinted polymers to:chemical sensors with capacitive detection is described. The sensitive layer was prepared b y electropolymerization of phenol on gold electrodes in the presence of the template (phenylalanine). The insulating properties of the polymer layer w ere studied by electrochemical impedance spectroscopy. Electrical leakages through the polymer layer were suppressed by deposition of a self-assembled monolayer of mercaptophenol before polymerization and of alkanethiol after polymerization. At the final stage of sensor preparation, the template was removed. The multilayer system obtained displayed a decrease in electrical capacitance on addition of phenylalanine. Only a low response was observed toward other amino acids and phenol.