Water soluble sulphur quantum dots for selective Ag+ sensing based on the ion aggregation-induced photoluminescence enhancement

Abstract

Quantum dots are promising fluorescent probes for metal ion detection, biosensing and bioimaging and so on. In this study, water-soluble sulphur quantum dots (SQDs) were used as a highly sensitive and selective sensor for fluorescence detection of silver(I) ions (Ag⁺) with a low detection limit (0.81 μM) and a wide linear range (0.8–280.8 μM). A nanoparticle aggregation-induced emission enhancement for SQDs coexisting with Ag⁺ was displayed for the first time. The practical use of this system for the determination of Ag⁺ in well water and tap water samples was also demonstrated successfully.