The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe³⁺ and Hg²⁺ Ions and Their Application as a Novel Fluorescent Sensor.

ABSTRACT: The fluorescence intensity of N, S co-doped graphene quantum dots (N, S-GQDs) can be quenched by Fe³⁺ and Hg²⁺. Density functional theory (DFT) simulation and experimental studies indicate that the fluorescence quenching mechanisms for Fe³⁺ and Hg²⁺ detection are mainly attributed to the inner filter effect (IFE) and dynamic quenching process, respectively. The electronegativity difference between C and doped atoms (N, S) in favor to introduce negative charge sites on the surface of N, S-GQDs leads to charge redistribution. Those negative charge sites facilitate the adsorption of cations on the N, S-GQDs' surface. Atomic population analysis results show that some charge transfer from Fe³⁺ and Hg²⁺ to N, S-GQDs, which relate

SUBMITTER: Yang Y 

PROVIDER: S-EPMC6566331 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature