Label-free tungsten disulfide quantum dots as a fluorescent sensing platform for highly efficient detection of copper(Ⅱ) ions

A fluorescent probe for the sensitive and selective determination of copper ion(Cu;) is presented. It is based on the use of tungsten disulfide quantum dots（WS;QDs） which is independent of the p H of solution and emits strong blue fluorescence. Copper ions could cause aggregation of the WS;QDs and lead to fluorescence quenching of WS;QDs. The change of fluorescence intensity is proportional to the concentration of Cu;, and the limit of detection is 0.4 μM. The fluorescent probe is highly selective for Cu;over some potentially interfering ions. These results indicate that WS;QDs,as a fluorescent sensing platform, can meet the selective requirements for biomedical and environmental application.