Desenvolvimento de um imunoensaio de fluxo lateral para a detecção de paraquat em amostras de alimentos

Abstract

Paraquat dichloride is one of the herbicides with the highest level of toxicity today, whose route of exposure for humans can be through contaminated food, especially when used as a desiccant agent. Conventional detection methods are very sensitive and specific, but the complex procedures and the need for trained personnel imply high costs and long times. This raises the need for a fast, easy-to-use detection method with high sensitivity and reproducibility, suitable for large-scale applications. Therefore, the main objective of this study was the development of a lateral flow immunoassay based on gold nanoparticles for the detection of paraquat dichloride in food samples. Regarding the results obtained, the optimal conditions for the assembly and operation of the lateral flow immunoassay were determined. Thus, an immunoassay was obtained whose qualitative results can be observed in 10 minutes from the insertion of the device in the sample. The visual and quantitative detection limits were 4ppb and 1.69 ppb, respectively. No cross-reaction with commonly used herbicides such as chlorpyrifos and glyphosate was observed when evaluating specificity. The coefficient of variation when evaluating repeatability was 3.27%. Finally, the lateral flow immunoassay was effectively applied for the detection of paraquat dichloride in soybean, potato and banana samples.