A Facile Hg2+‐related Quenching Photoluminescence Sensor Based on Nitrogen‐doped Graphene Quantum Dots

A Hg2+‐related quenching photoluminescence (PL) sensor was fabricated based on nitrogen‐doped graphene quantum dots (N‐GQDs) as the luminescent agent and glutathione as the masking agent to detect Hg2+ in tap water. The addition of Hg2+ significantly reduced the PL intensity of N‐GQDs, which was attributed to coordination reaction inducing the aggregation of N‐GQDs. The Hg2+‐related quenching PL sensor with glutathione as the masking agent has good selectivity and accuracy. The sensor showed a linear relationship ranging from 0.5 to 110 nM with the detection limit 0.08 nM (S/N = 3). The proposed method was applied to the determination of Hg2+ in tap water, and the results were consistent with atomic absorption spectroscopy (AAS).