Green Synthesis of Fluorescent Carbon Quantum Dots for Detection of Hg super(2+)

Fluorescent carbon quantum dots (CQDs) were synthesized by one-step hydrothermal treatment of apple juice. Experiments showed that Hg super(2+) could quench the fluorescence of the CQDs with specificity. Based on this phenomenon, a selective and sensitive sensor was constructed for Hg super(2+) detection. In a NaH sub(2)PO sub(4)-Na sub( 2)HPO sub(4) buffer solution (pH 7.0), their fluorescence intensity showed good linear relationship with the concentrations of Hg super(2+) from 5 to 100 nmol/L and 1 to 50 mu mol/L, respectively, with the detection limit of 2.3 nmol/L (S/N = 3). Its practical application was further demonstrated by the detection of Hg super(2+) in real water samples.