Enhanced Bio-Barcode Immunoassay Using Droplet Digital PCR for Multiplex Detection of Organophosphate Pesticides

Abstract

A bio-barcode immunoassay based on droplet digital polymerase chain reaction (ddPCR) was developed to simultaneously quantify triazophos, parathion, and chlorpyrifos in apple, cucumber, cabbage, and pear. Three gold nanoparticle (AuNP) probes and magnetic nanoparticle (MNP) probes were prepared, binding through their antibodies with the three pesticides in the same tube. Three groups of primers, probes, templates, and three antibodies were designed to ensure the specificity of the method. Under the optimal conditions, the detection limits (expressed as IC 10 ) of triazophos, parathion, and chlorpyrifos were 0.22, 0.45, and 4.49 ng mL −1 , respectively. The linear ranges were 0.01−20, 0.1−100, and 0.1−500 ng mL −1 , and the correlation coefficients (R 2 ) were 0.9661, 0.9834, and 0.9612, respectively. The recoveries and relative standard deviations (RSDs) were in the ranges of 75.5−98.9 and 8.3−16.7%. This study provides the first insights into the ddPCR for the determination of organophosphate pesticides. It also laid the foundation for high-throughput detection of other small molecules.

A Portable Fluorescent Hydrogel-Based Device for On-Site Quantitation of Organophosphorus Pesticides as Low as the Sub-ppb Level

“…Organophosphorus pesticides (OPs) have a crucial role in efficiently protecting modern agriculture from damage by pests (He et al, 2021;Wang T. et al, 2021). Unreasonable usage of OPs will inevitably cause an increase in pesticide residues in agricultural foods, leading to environmental bioaccumulation and further causing huge health hazards to humans (Cui et al, 2021;Dong et al, 2021;Li Q. et al, 2021;Mariyappan et al, 2021;Yao et al, 2022). Hence, there is a stringent demand to exploit simple, effective, and fast-sensing technologies for the analysis of OP residues.…”