Highly Selective Detection of Metronidazole by Self-Assembly via 0D/2D N–C QDs/g-C(3)N(4) Nanocomposites Through FRET Mechanism

ABSTRACT: A 0D/2D (0-dimensional/2-dimensional) nanostructure was designed by self-assembly of N–C QDs and carboxylated g-C(3)N(4) nanosheets and used as a fluorescence resonance energy transfer (FRET) fluorescent sensor. The N–C QDs/g-C(3)N(4) nanosheets were synthesized via the amino group on the N–C QD surface and the –COOH of the carboxylated g-C(3)N(4) nanosheets. The mechanism of detection of metronidazole (MNZ) by N–C QDs/g-C(3)N(4) nanocomposites is based on FRET between negatively charged N–QDs and positively charged carboxylated g-C(3)N(4) nanoparticles. N–C QDs/g-C(3)N(4) nanostructures displayed good responses for the detection of MNZ at normal temperature and pressure. The decrease in the fluorescence intensity showed a good linear relationship to MNZ concentration within 0–2.6 × 10(−5) mol/L, and the detection limit was 0.66 μM. The novel FRET sensor will have a great potential in clinical analysis and biological studies. GRAPHICAL ABSTRACT: [Image: see text]