Abstract:

Methyl paraoxon was subjected to explore the optimal parameters of colloidal gold immune chromatography. First, currently available antibody purification methods were screened to decide the optimal one based on SDS-PAGE. The obtained optimal method was used to purify methyl paraoxon antibodies. Then, the labeling was completed through the reaction between purified polycolonial antibodies and colloidal gold solutions with 30 nm of particle size. Reaction solutions were further screened to determine the optimal re-suspension, dilution of antigens and treatment solutions for sample pads. Finally, the dipsticks with colloidal gold were developed, which exhibited simple and rapid detection of methyl paraoxon. The final performance on these test strips was evaluated and the detection limit for targets was 5μg/ml using naked eye.

Key words: methyl paraoxon, colloidal gold, pesticide residue detection, dipstick, rapid detection