Mn-doped ZnS quantum dots/methyl violet nanohybrids were explored to develop a novel room temperature phosphorescence (RTP) sensor for the detection of DNA. Methyl violet (MV) as the electron acceptors was adsorbed on the surface of the quantum dots (QDs) to quench the RTP of the Mn-doped ZnS QDs through an electron-transfer process under excitation. The addition of DNA recovered the RTP signal of the Mn-doped ZnS QDs due to the binding of MV with DNA and the removal of MV from the surface of the Mn-doped ZnS QDs. Under the optimal conditions, the enhanced RTP intensity of the Mn-doped ZnS QDs/MV nanohybrids linearly increased with the concentration of DNA from 0.08 to 12 mg L-1 with the detection limit of 33.6 μg L-1. The relative standard deviation for eleven replicate detections of the reagent blank was 3.7%. The developed method was applied to the detection of DNA in spiked urine samples with recoveries of 96%-103% without interference from nonspecific fluorescence.
