Biomimicking, metal-chelating and surface-imprinted polymers for the degradation of pesticides

Molecularly imprinted polymer beads (PIBs) and non-imprinted (control) polymer beads (NIBs) have been prepared from methacryloylhistidine-Co2+, -Ni2+, and -Zn2+ monomers and applied as catalyst in the hydrolysis of paraoxon which is an organophosphate ester and used as a pesticide. The PIBs were prepared by a molecular surface imprinting technique. The catalytic performance of these polymers having Co2+, Ni2+ and Zn2+ ions in their catalytic active centers was evaluated according to the enzyme kinetic model of Michaelis-Menten and their activities were compared to each other. PIBs always showed higher catalytic activities than NIBs analogues. In addition, the imprinted polymers of methacryloylhistidine-Co2+, -Ni2+, or -Zn2+ complexes provided hydrolysis rate enhancements by a factor of 356, 241, and 95, respectively, compared to the rate in non-catalyzed media that contains only buffer.