MnII-Doped ZnS Quantum Dots Modified with Tiopronin for Mercury(II) Detection

Abstract

The simple, low-cost, and rapid detection of aqueous mercuric ions remains a challenge for environmental and biological monitoring and protection. We demonstrate herein a new analytical method to detect Hg2+ based on MnII-doped ZnS quantum dots modified with tiopronin. At pH 7.2, Hg2+ causes the fluorescence intensity of quantum dots modified with tiopronin to decrease linearly proportionally with the concentration of Hg2+. This method is non-responsive to general metal ions, surfactants, and some biomacromolecules even though their concentrations were greater than that of Hg2+. Therefore, a sensitive and selective fluorescence assay for Hg2+ with a low limit of detection (8.9 × 10–9 mol L–1) has been developed and its successful application in real samples such as tap water, lake water, and human serum are also discussed in detail.