Development of a one-step strip for the detection of triazophos residues in environmental samples

Environmental and food safety issues now are recognized internationally, and pesticide residues play key roles as environment and food pollutants. It is crucial to develop methods for rapid determination of pesticide residues in environments and foods. A one-step strip based on nanocolloidal-gold-labeled monoclonal antibodies for detection of triazophos residue was developed. The nanocolloidal gold, with an average particle diameter of 25 nm (G25), was labeled to an antitriazophos monoclonal antibody. This conjugate was dispensed on the conjugate pad of a porous glass fiber. Ovalbumin hapten and goat anti-mouse IgG were dispensed on the nitrocellulose membrane and served as the test line (T-line) and control line (C-line), respectively. After conditions optimization, the one-step strip was finally developed for the residue determination of triazophos. The limit of detection (LOD) of the strip was 4 ng/mL for standard. The detection was not affected by the pH of the liquid sample but low total ion concentration will induce illegible C-line and T-line. The LOD for spiked samples of soil and water was 5 ng/mL, with run time of no more than 10 min.