Efficient detection for Nitrofurazone based on novel Ag2S QDs/g-C3N4 fluorescent probe

In the paper, a novel fluorescent probe based on Ag 2 S QDs/g-C 3 N 4 composite was synthesized by loading Ag 2 S quantum dots (Ag 2 S QDs) on the surface of g-C 3 N 4 through in-situ synthesis method and developed to detect Nitrofurazone (NFZ) sensitively. The results showed that the linear detection range of Ag 2 S QDs/g-C 3 N 4 to NFZ was 0–30 μM, with a low detection limit of 0.054 μM. The results of time-fluorescence-resolved spectroscopy and UV–vis absorption spectroscopy exhibited that the possible detection mechanism of Ag 2 S QDs/g-C 3 N 4 to NFZ was proposed to be Internal Filtration Effect (IFE). Moreover, Multiwfn wavefunction analysis was employed to uncover the possible interaction between the Ag 2 S QDs/g-C 3 N 4 and NFZ, thereby further revealing the fluorescence detection mechanism from the scale of atoms. Combining experiments and theoretical calculations, we proposed the sensing mechanism of the formation of non-fluorescent ground state complex linked by hydrogen bonds. This work indicated that the Ag 2 S QDs/g-C 3 N 4 composite processed the ability to detect NFZ efficiently and sensitively.