Nitrogen, sulfur, boron and flavonoid moiety co-incorporated carbon dots for sensitive fluorescence detection of pesticides

Multiple dopants contained carbon dots (CDs) with enhanced selectivity have aroused extensive attentions. In this work, three heteroatoms (nitrogen, sulfur, boron) and flavonoid moiety derived from the extracts of Ginkgo biloba leaves co-incorporated CDs were synthesized based on the hydrothermal strategy for novel carbon materials investigation and sensing applications. Nitrogen and flavonoid moiety co-doped CD (N-CD-Fla), nitrogen, sulfur, and flavonoid moiety co-doped CD (NS-CD-Fla), nitrogen, sulfur, boron and flavonoid moiety co-doped CD (NSB-CD-Fla) were prepared, respectively. Three CDs had diversities in nanoparticle sizes, chemical structures, and luminescence properties. NS-CD-Fla exhibited blue luminescence and had higher quantum yield (QY) than N-CD-Fla (yellow-green) and NSB-CD-Fla (blue-green), which can be attributed to its higher N content and N, S synergistic enhancement effect. The luminescence of the three CDs was speculated to be related with the electron transition of CN bonds derived from grafting amines groups onto the flavonoid-related moieties. N-CD-Fla, NS-CD-Fla, and NSB-CD-Fla were further proved to be sensitive to fenitrothion (Fen), dithianon (Dit), dinoseb (Din) and their structural analogues, they were employed as superior chemosensors for the three pesticides sensitive and selective detection. The application potentials of the novel chemosensors based analytical methods were further evaluated by real sample analysis.