Glutathione-functionalized Mn:ZnS/ZnO core/shell quantum dots as potential time-resolved FRET bioprobes

High-quality glutathione-capped Mn:ZnS/ZnO core/shell quantum dots were prepared in aqueous solution through the nucleation-doping method by using low-cost inorganic salts as precursors. Remarkable improvements of photoluminescence (PL) were achieved by introduction of a ZnO shell around the Mn:ZnS QDs through basic hydrolysis of Zn(NO3)2. The Mn:ZnS/ZnO quantum dots have been demonstrated to be sensitive time-resolved Forster resonance energy transfer (TR-FRET) bioprobes for the detection of a trace amount of biomolecules such as avidin at a concentration of 3 nM with a linear response ranging from 10 to 100 nM. We anticipate that the QDs may have great potential for versatile applications in biodetection and bioimaging.