Simultaneous detection of mercury(II) ion and biological thiols utilizing high quantum yield nitrogen- and sulfur-co-doped carbon dots

摘要

A novel simultaneous detection mercury(II) (Hg~(2+)) and biological thiols method utilizing high quantum yield nitrogen- and sulfur-co-doped carbon dots (C/N/S dots) was obtained. The water-soluble, photoluminescent C/N/S dots with a quantum yield of approximately 11.88% by the hydrothermal process using L-Cysteine and ascorbic acid as a carbon, nitrogen and sulfur source for the first time. The asprepared fluorescent C/N/S dots showed highly efficient fluorescent quenching ability in the presence of mercury(II) (Hg~(2+)) due to the formed nonfluorescent metal complexes via robust Hg~(2+)-S interaction with the S and N of fluorescent C/N/S dots, which allowed the analysis of Hg~(2+) ions in a very simple method. However, in the presence of biological thiols, the Hg~(2+) prefers to combine with biological thiols to release C/N/S dots, which results in the photoluminescence to recover. By employing this method, excellent linear relationships existed between the quenching degree FL intensity of the C/N/S dots and concentrations of Hg~(2+) ions and recovery degree of L-cysteine and glutathione.