Development of a surface-enhanced Raman scattering-based immunochromatographic assay for sensitive detection of...

In this study, novel tungsten disulfide (WS₂)-gold composite core-shell (WS₂@Au) nanoparticles were used to label carbaryl antibodies and Raman molecule 5,5-dithiobis-2-nitrobenzoic acid (DTNB) to synthesize Raman immune probes. A highly sensitive surface-enhanced Raman scattering-based immunochromatographic assay (SERS-ICA) was developed for the quantitative detection of carbaryl residues. Under optimized conditions, the detection linear range was 0.1 to 10³ ng mL^-1, and the detection limit was 2.26 × 10^-3 ng mL^-1. The method for detection of carbaryl had high specificity, without any cross-reaction observed in other pesticides. Recoveries of carbaryl from spiked fruits and vegetables were 89% to 112%, with the coefficient of variation less than 7%. The established SERS-ICA method provides a rapid, ultrasensitive, and reliable strategy for on-site screening and quantitative analysis of carbaryl residues in complex food matrices, highlighting its strong potential for practical food safety monitoring.