Nitrogen and Sulfur Co-Doped Carbon Quantum Dots Fluorescence Quenching Assay for Detection of Mercury (Ii) Publisher Pubmed



Chaghaghazardi M^{1, 3} ; Kashanian S^{1, 2} ; Nazari M¹ ; Omidfar K^{3, 4} ; Joseph Y^{5, 6} ; Rahimi P^{5, 6} Show Affiliations
Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy Published:2023

Abstract

Mercury is a highly toxic and potentially bioaccumulative heavy metal ion that can cause severe health problems in humans even at very low concentrations. Thus, the development of a simple, rapid, and sensitive assay for the effective detection of mercury ions at trace levels is of great importance. Here, nitrogen and sulfur co-doped carbon quantum dots (N,S-CQD) were synthesized by a simple hydrothermal treatment of chitosan in the presence of thiourea and citric acid with a quantum yield (QY) up to 33.0 % and used as a selective fluorescent probe to detect mercury ions (Hg2+). The effect of pH, ionic strength, and time on the fluorescence intensity of N,S-CQD were investigated and optimized. The synthesized N,S-CQD showed ultrasensitive ability to detect Hg2+ ions in the water samples, also in the presence of 11 interfering metal ions, with a low detection limit (∼4 nM) over a wide linear range from ∼5–160 nM. The sensing performance of N,S-CQD probe in real sample applications was evaluated by the detection of Hg2+ in lake water samples, which confirmed its potential application in environmental analysis. © 2023