Room-temperature phosphorescence probe based on Mn-doped ZnS quantum dots for the sensitive and selective detection of selenite

The room-temperature phosphorescence (RTP) of Mn-doped ZnS quantum dots (Mn-ZnS QDs) was quenched by the addition of selenite in the presence of glutathione. The quenching of the RTP emission of Mn-ZnS QDs was due to HSe- ions which was the reaction product of selenite and glutathione. Based on the above finding, a simple, rapid, sensitive probe for selective detection of selenite was successfully fabricated. Under the optimal experimental conditions, a linear relationship was obtained covering the linear range of 0.1-5.0 mmol L-1 and the detection limit (3s) was 0.085 mmol L-1. The proposed method was successfully applied for the determination of selenite in sodium selenite tablets and sodium selenite and vitamin E injection with satisfactory results.