Electrosynthesized molecularly imprinted polypyrrole films for enantioselective recognition of l-aspartic acid

The electrosynthesis, overoxidation and characterization of l-aspartic acid (l-Asp) imprinted polypyrrole (PPy) films have been performed by using electrochemical quartz crystal microbalance (EQCM). Following the determination of the optimal electrosynthesis parameters for the formation of a smooth and uniform PPy/l-Asp films, the overoxidized polypyrrole (oPPy) matrix templated with either l- or d-aspartic acid (l-, d-Asp) was evaluated as a potential enantioselective recognition element. Under potentiodynamic conditions and in strongly acidic media a significantly higher sensitivity of the l-Asp acid imprinted overoxidized polypyrrole film (oPPy/l-Asp) for l-Asp than d-Asp was observed. The results suggest the feasibility of preparing molecularly imprinted films by electropolymerization for the enantioselective recognition of amino acids and the suitability of EQCM for both monitoring the selective recognition as well as to electrochemically modulate the binding process.