A dual-emission CD@AuNCs fluorescent sensor for Carbaryl detection in food

Carbaryl, a broad-spectrum carbamate insecticide, is widely used to enhance agricultural productivity; however, its hazardous residues pose significant food safety risks. In this study, dual-emission nanohybrids (CD@AuNCs) were synthesized by leveraging the active groups on CDs and BSA-AuNCs. The nanohybrids facilitated the ratiometric fluorescence detection of Carbaryl based on an aggregation-induced emission enhancement (AIE) mechanism. The sensor exhibited a linear range of 1–100 mg/kg and a detection limit of 0.95 mg/kg, which is below the maximum residue limit for Carbaryl (5 mg/kg, Chinese National Standard GB 2763–2021). The method was validated through recovery experiments in actual food samples, yielding results consistent with those obtained by LC-MS analysis. This sensitive, stable, and ratiometric fluorescence method thus offers a reliable analytical strategy for detecting Carbaryl in food matrices, demonstrating significant potential for applications in food safety monitoring and pesticide residue analysis.