Journal of Catalysis, Vol.380, 83-90, 2019
Rapid hydrolysis of nerve agent simulants by molecularly imprinted porous crosslinked polymer incorporating mononuclear zinc(II)-picolinamine-amidoxime module
Effective catalyst material capable of rapid organophosphate (OP) detoxification is highly imperative for practical application. Herein, taking advantage of molecular imprinting technique with solvothermal method, molecular imprinted porous crosslinked polymers (MIPCPs) incorporating mononuclear zinc (II)-picolinamine-amidoxime (Zn-PAAO) functional module is developed as organophosphorus hydrolase (OPH) mimic to realize rapid OP hydrolysis in minute level. The synergy of monopyridyl with amidoxime of Zn-PAAO generates a reactive Lewis acidic zinc(II) ion and a strong free oxime nucleophile at the active center of MIPCPs. The as-fabricated MIPCP-Zn-PAAO displays extremely high catalytic ability for both phosphotriester and phosphodiester hydrolysis under mild condition (pH = 9, 30 degrees C). Advantageously, the observed pseudo first rate constant (k(obs)(MIPCP)) of MIPCP-Zn-PAAO-80% for diethyl 4-nitrophenyl phosphate (DENP, a nerve agent stimulant) hydrolysis is 2 x 10(4)-fold higher than that of self-hydrolysis. The maximum velocity (V-max) of MIPCP-Zn-PAAO-80% for DENP hydrolysis is even 6.9 times higher than that of the reported free organophosphorus hydrolase (OPH), representing the highest level among current polymer enzyme mimics. Our work provides a new promising strategy for effective OP catalytic degradation. (C) 2019 Elsevier Inc. All rights reserved.
Keywords:Organophosphate catalysis hydrolysis;Pyridine;Amidoxime derivative;Molecular imprinted porous crosslinked polymer