An artificial phosphotriesterase (PTE) was constructed by co-polymerization of 4(5)-vinylimidazole-Zn2+-methacrylic acid cluster with a divinylbenzene polymer. Compared with the spontaneous hydrolysis, the resulting polymer catalyst caused 105-fold rate acceleration towards the hydrolysis of diethyl p-nitrophenyl phosphate ( Paraoxon). The catalytic activity of the polymer catalyst could be enhanced for 30% using molecular imprinting technique and the molecularly-imprinted catalyst (MIC) showed a turnover rate of 7.4 x 10(-2) s(-1) towards the hydrolysis of Paraoxon. The MIC also hydrolyzed thiophosphates and phosphorothiolate triester pesticides. Construction of an amperometric sensor employing the MIC as catalyst achieved a detection limit of 0.1 mM Paraoxon.