One-Step Hydrothermal Synthesis of Highly Fluorescent MoS2 Quantum Dots for Lead Ion Detection in Aqueous Solutions

Lead ions in water are harmful to human health and ecosystems because of their high toxicity and nondegradability. It is important to explore effective fluorescence probes for Pb2+detection. In this work, surface-functionalized molybdenum disulfide quantum dots (MoS2QDs) were prepared using a hydrothermal method, and ammonium tetrathiomolybdate and glutathione were used as precursors. The photoluminescence quantum yield of MoS2QDs can be improved to 20.4%, which is higher than that for MoS2QDs reported in current research. The as-prepared MoS2QDs demonstrate high selectivity and sensitivity for Pb2+ions, and the limit of detection is 0.056 μM. The photoluminescence decay dynamics for MoS2QDs in the presence of Pb2+ions in different concentrations indicate that the fluorescence quenching originated from nonradiative electron transfer from excited MoS2QDs to the Pb2+ion. The prepared MoS2QDs have great prospect and are expected to become a good method for lead ion detection.Keywords:molybdenum disulfide;quantum dots;lead ion;fluorescence probe