Fluorinated Silicon Quantum Dots for Broad-Spectrum Fluorescence Detection of Pyrethroids via Structure–performance Enhancement

The pervasive use of pyrethroids and their potential for bioaccumulation necessitate the development of rapid, broad-spectrum, and field-deployable monitoring tools. A novel sensing strategy using fluorinated silicon quantum dots (FSiQDs) for the indirect detection of pyrethroids was developed by targeting their universal degradation product, 3-phenoxybenzaldehyde (3-PBD). FSiQDs modified with 3,5-difluorophenylhydrazine exhibited superior quenching rate (71.32%) toward 3-PBD through a Schiff base-mediated static quenching mechanism. Under optimized conditions, the sensor achieved a limit of detection (LOD) of 0.28 μM within a 10 min response time. To facilitate on-site analysis, an integrated portable fluorescence detector (PFD) was engineered, demonstrating reliable performance in waters from Taihu, Yangcheng, and Cheng Lakes with recoveries ranging from 96.96% to 102.67%. This work represents the first application of fluorine-doped SiQDs for fluorescence sensing, offering a practical solution for the rapid, broad-spectrum screening of pesticide residues in complex environmental and food matrices.