Potential-induced enantioselective uptake of amino acid into molecularly imprinted overoxidized polypyrrole

Overoxidized polypyrrole films templated with L-glutamate have been utilize d for enantioselective detection of L- and D-glutamic acid. Various importa nt fabrication factors controlling the performance of the overoxidized poly pyrrole films have been investigated using fluorescence spectrometry in con jugation with the electrochemical quartz crystal microbalance technique. Th e measured fluorescence intensity was related to the concentration of gluta mate taken up into the films. It was found that L-glutamate was inserted si milar to 30 times higher into the film than D-glutamate. Several key parame ters such as applied potential and pH of amino acid solution were varied to achieve the optimum sensor response. The sensor templated with L-glutamic acid also exhibited excellent selectivity over several other L- and D-amino acids. Higher enantioselectivity of overoxidized polypyrrole film than tha t for previously reported imprinted polymers can be attributed to the poten tial-induced uptake/release of targeted molecules.