AuNCs@ZIF-8 with enhanced AIE effect to develop a lateral flow immunosensor for POC dual-modal detection of acetochlor.

Regarding the high incidence of residue and serious toxicity of acetochlor (ATC) pesticide, it is urgent to explore simple and low-cost methods for their sensitive detection in food. In this study, with zeolite-like imidazole frameworks (ZIFs) as the carriers for embedding glutathione-modified luminescent gold nanoclusters (GSH-AuNCs) exhibiting aggregation-induced emission (AIE) effect, a GSH-AuNCs@ZIF-8 probe driven strip-based lateral flow immunosensor (LFIS) was developed for visual qualitative and fluorescent quantitative dual-modal detection of ATC. The encapsulation of GSH-AuNCs into ZIF-8 with restriction effect not only significantly improved the stability and anti-interference ability of AuNCs, but also remarkably enhanced the fluorescence efficiency for signal amplification due to the enhanced AIE effect of GSH-AuNCs, endowing the LFIS platform with unique performance. Under optimal conditions, the LFIS platform could realize the point-of-care visualization and quantitation of ATC within 20 min with a detection limit of 8.3 pg/mL and a broad linear range of 0.01-10.0 ng/mL. High recoveries of 96.44%-106.8 % in the spiked ginger samples confirmed the outstanding accuracy and dependability of the new platform for ATC analysis of real samples. Compared with other immunoassays, the AuNCs@ZIF-8-based dual-modal LFIS exhibited the advantages of simple preparation, simple operation, short analytical time, and low cost, which could be expanded to monitor more pesticides and more trace contaminants in diverse food and agricultural products, and medicinal material matrices.