A bare-eye-based lateral flow immunoassay based on the use of gold nanoparticles for simultaneous detection of three pesticides

We present a novel lateral flow immunoassay (LFIA) for the simultaneous detection of the pesticides imidacloprid, chlorpyrifos-methyl and isocarbophos based on three competitive immunoreactions. In contrast to previously reported LFIAs, the method is based on the use of four strips. Each has three red channels (three test lines dispensed with different capture reagent) to detect imidacloprid, chlorpyrifos-methyl and isocarbophos respectively. Different channels on each strip are the key to multi-detection, and four strips of LFIA are needed for visual and semi-quantitative read-outs. Under optimized conditions, the LFIA was applied to the determination of three pesticides. The detection time is within 7 min and the detection limits are 50, 100, and 100 mu g L-1, respectively. Furthermore, the LFIA was applied to the analysis of spiked Chinese cabbage and soil samples and results were validated by HPLC.