Duplex-Specific Nuclease-Triggered Fluorescence Immunoassay Based on Dual-Functionalized AuNP for Acetochlor, Metolachlor, and Propisochlor

作者：Yonghong Zha, Yansong Li, Pan Hu, Shiying Lu, Honglin Ren, Zengshan Liu, Hualin Yang, Yu Zhou · 发表于：Analytical Chemistry · 年份：2021 · DOI：10.1021/acs.analchem.1c02736 · 被引用次数：34 · 研究领域：Advanced biosensing and bioanalysis techniques、Pharmaceutical and Antibiotic Environmental Impacts、Pesticide and Herbicide Environmental Studies

Given the great harm of pesticide residues to the environment and public health, exploring ultrasensitive and low-cost methods for their quantitative analysis becomes intensely necessary. Herein, we proposed a double-functionalized gold nanoparticle (AuNP) probe as a signal amplification immunoassay for the detection of acetochlor (ATC), metolachlor, and propisochlor. The AuNP was modified with IgG and fluorophore-labeled duplex DNA by a polyadenine-based freezing method. The quenched fluorescence can be effectively recovered via duplex-specific nuclease (DSN) with excellent cleaving activity. This approach provided limits of detection (LODs) down to 0.03 ng/mL for ATC, 0.10 ng/mL for metolachlor, 0.14 ng/mL for propisochlor, and 0.08 ng/mL for their mixture. The average recoveries of ATC, metolachlor, and propisochlor were 93.0–106.6% from a corn sample, which are in good agreement with the commercial kit ( R 2 = 0.9995). This “turn-off” fluorescence immunoassay presents considerable potential in the analysis of chloroacetamide herbicide due to its simple process of probe preparing and ultrahigh sensitivity.