Abstract:In order to evaluate the possibility of esterase from wheat bran for rapid detection of organophosphorus and carbamate pesticides, sensitization effect of surfactants on the fast blue B salt chromogenic reaction system were determined, and sensitivity and limit of detection of 6 different pesticides detection (dichlorvos, isoprocarb, carbaryl, methyl parathion, carbosulfan and rogor) by wheat bran esterase-α-naphthol-fast blue B salt reaction were measured. The results indicated that the anion surfactant SDS (sodium dodecyl sulfonate) could sensitize the colour reaction, and the absorbance value was increased by 152.76% when the SDS was added as concentration of 4.0%. The most restricted time of isoprocarb on the esterase for was 40 minutes, while other pesticides restricted time were 30 minutes. The sensitivity of wheat bran esterase to 6 different pesticides ranged in order as follow: dichlorvos > isoprocarb > carbaryl >methyl parathion > carbosulfan > rogor, and IC50 value were 0.136, 0.375, 0.641, 1.366, 2.361 and 2.651 mg·L-1 respectively. The esterase had more sensitivity to the methyl parathion oxidated by bromine, and the IC50 was 0.089 mg·L-1. In conclusion, the wheat bran esterase has higher sensitivity in the rapid detection of organophosphorus and carbamate pesticides. And the obtained esterase could meet the requirement for enzyme inhibition rapid detection of pesticides residues. It enriched a foundation for the application of wheat bran esterase in rapid detection of pesticide residues.