A highly sensitive ratiometric fluorescent sensor for copper ions and cadmium ions in scallops based on nitrogen doped graphene quantum dots cooperating with gold nanoclusters. (1st February 2022) - Gao, Xue
Graphical abstract: Highlights: GQDs-AuNCs ratiometric fluorescent sensor was prepared by electrostatic interaction. The sensor was used to detect Cu 2+ and Cd 2+ in scallops. The paper-based sensor can be used for semi-quantitative detection of Cu 2+ and Cd 2+ . The detection limits are 4.12 nM for Cu 2+ and and 943 nM for Cd 2+, respectively. Abstract: Based on the electrostatic interaction, we constructed a ratiometric fluorescence nanomixture of graphene quantum dots-gold nanoclusters (GQDs-AuNCs) for the quantitative detection of Cu 2+ and Cd 2+ . When Cu 2+ or Cd 2+ was added into the reaction system, the fluorescence of GSH-AuNCs at 565 nm can be quenched by Cu 2+ and enhanced by Cd 2+ while the intensity of N -GQDs at 403 nm stayed constant. Under the optimized conditions, the fluorescence intensity ratio (I565 /I403 ) of the GQDs-AuNCs system was proportional to the concentration of Cu 2+ and Cd 2+ in the range of 8×10 −8 mol/L-6×10 −6 mol/L and 1×10 −6 mol/L-4×10 −5 mol/L, respectively, with detection limits of 4.12×10 −9 mol/L and 9.43×10 −7 mol/L, respectively. In the presence of Cu 2+ and Cd 2+, the paper-based vision sensor would produce visible fluorescent color changes, which can be used for rapid detection on site. The method has been successfully applied to the determination of Cu 2+ and Cd 2+ in scallops with satisfactory results.