Preparation of near-infrared Ag2 S quantum dots for detection of bisphenol A in water

The work develops a novel method for the detection of bisphenol A (BPA) based on glutathione (GSH)-protected silver sulphide quantum dots (Ag 2 S QDs), which was simple, fast, non-toxic, sensitive and selective. Ag 2 S QDs were synthesised with a sulphur–hydrazine hydrate complex as the S 2− source and GSH as the stabiliser. Ag 2 S QDs, near-infrared QDs, offered the advantages over lower background fluorescence and lower signal loss. The fluorescence peak of Ag 2 S QDs at 650 nm was quenched significantly in the presence of BPA. Good linear correlations were obtained over the concentration range from 0 to 60 μM of BPA under optimised conditions. The developed selective and sensitive method presaged more opportunities for the application in environmental samples.