Development of a highly sensitive colloidal gold semiquantitative method for the determination of difenoconazole residues in citrus

Front Nutr. 2024 Mar 25:11:1341219. doi: 10.3389/fnut.2024.1341219. eCollection 2024.

Abstract

Introduction: Difenoconazole (DIFE) is a common pesticide used in citrus cultivation; excessive intake can cause neurological damage to the organism, and the existing colloidal gold immunochromatographic test strips cannot meet the requirements for the detection of citrus samples.

Methods: Difenoconazole test strip was prepared based on the colloidal gold immunochromatographic technique (GICT), and its application in citrus samples was investigated; with colloidal gold (CG) as the probe, the optimization of GICT parameters, and the determination of reaction method, the immunochromatographic test strips for the detection of DIFE in citrus was developed, and the limit of detection (LOD), specificity, accuracy, and stability of the test strips were verified.

Results: The results showed that the visual detection limit of the prepared colloidal gold immunochromatographic test strips was 0.2 mg/kg and the quantitative range was 0.06-0.6 mg/kg, and the test strips could specifically identify DIFE and have no cross-reaction with other common triazole pesticides. The detection method established in this study was verified by the GC-MS method, and the detection results achieved good consistency (R2 > 0.98).

Conclusion: The test strips developed in this study have good performance and can be used for highly sensitive detection of citrus samples.

Keywords: colloidal gold immunochromatographic technique; detection limit; difenoconazole; gold nanoparticles; rapid diagnosis strips.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The study was supported by the Key Research and Development Program Projects of Hebei (20325501D, 18227138D), the Heibei Open-field Vegetable Innovation Team of Modern Agro-industry Technology Research System (HBCT2024140209), and the Research on high-throughput detection technology and early warning decision-making platform for non-targeted pesticide residues in vegetables in Hainan (ZDYF2022XDNY232).