Fluorescence immunoassay for multiplex detection of organophosphate pesticides in agro-products based on signal amplification of gold nanoparticles and oligonucleotides

• Published in: Food chemistry Vol. 326; p. 126813
• Main Authors: Zhang, Chan, Jiang, Zejun, Jin, Maojun, Du, Pengfei, Chen, Ge, Cui, Xueyan, Zhang, Yudan, Qin, Guoxin, Yan, Feiyan, Abd El-Aty, A.M., Hacimüftüoğlu, Ahmet, Wang, Jing
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2020
• Subjects: Fluorescence immunoassay; Gold nanoparticle; Oligonucleotide; Organophosphate pesticides; Chlorpyrifos (PubChem CID: 2730); Parathion (PubChem CID: 991); Dithiothreitol (PubChem CID: 446094); Fluorescence immunoassay; Oligonucleotide; Triazophos (PubChem CID: 32184); Organophosphate pesticides; Gold nanoparticle
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.126813

•A multiplex fluorescence immunoassay for organophosphate pesticides analysis was developed.•AuNPs probes were constructed with antibodies and oligonucleotides to amplify the signal.•Multiple chemical residues analysis can be done in a single well.•The method shows a high sensitivity and a good precision.•The method can provide a reference for multi-residue analysis of small molecule contaminants. Herein, we developed a multi-analyte fluorescence immunoassay for detection of three organophosphate pesticides (triazophos, parathion, and chlorpyrifos) in various agro-products (rice, wheat, cucumber, cabbage, and apple) using fluorescently labeled oligonucleotide and gold nanoparticle (AuNP) signal amplification technology. The AuNP probes for the three analytes were constructed by simultaneously modifying the corresponding antibodies and fluorescently labeled oligonucleotides on the probe surface. Three fluorophores (6-FAM, Cy3, and Texas red) with high fluorescence intensity and little overlap of excitation/emission wavelengths were selected. The method showed satisfactory linearity for triazophos, parathion, and chlorpyrifos in the ranges of 0.01–20, 0.05–50, and 0.5–1000 μg/L, respectively. For the 3 analytes, the limits of detection (LODs) were 0.007, 0.009, and 0.087 μg/L, respectively. The average recoveries were 77.7–113.6%, with relative standard deviations (RSDs) of 7.1–17.1% in various food matrices. The proposed method offers great potential in food safety surveillance, and could be used as well as a reference for multi-residue analysis of other small-molecule contaminants.