Dual-Mode Optical Detection of Sulfide Ions Using Copper-Anchored Nitrogen-Doped Graphene Quantum Dot Nanozymes.

ABSTRACT: We present a dual-mode optical sensing strategy for selective and sensitive detection of sulfide ions (S2-), employing copper-anchored nitrogen-doped graphene quantum dots (Cu@N-GQDs) as bifunctional nanozymes. The Cu@N-GQDs were synthesized via citric acid pyrolysis in the presence of ammonium hydroxide (serving as both nitrogen source and reductant) and copper chloride, leading to uniform incorporation of copper oxide species onto the N-GQD surface. The resulting nanohybrids exhibit two synergistic functionalities: intrinsic fluorescence comparable to pristine N-GQDs, and significantly enhanced peroxidase-like catalytic activity attributed to the anchored copper species. Upon interaction with sulfide ions, the system undergoes a dual-optical response: (i) fluorescence quenching via Cu-S

SUBMITTER: Nguyen VAN 

PROVIDER: S-EPMC12384640 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature