A Convenient “Turn On-off” Phosphorescent Nanosensor for Detection of Biotin Based on Quantum Dots/CTAB

A switchable room-temperature phosphorescence(RTP) nanosensor based on an MPA-capped Mn-doped ZnS QDs/CTAB composite system(MPA=3-mercaptopropionic acid; CTAB=cetyltrimethyl ammonium bromide; QDs=quantum dots) was established for the detection of biotin. The phosphorescence intensity of QDs/CTAB could be regularly quenched with the increase of biotin. Under optimal conditions, this method yielded two linear ranges of 2-20 μg/L and 20-140 μg/L with respective correlation coefficients of 0.993 and 0.990, as well as a detection limit of 0.93 μg/L. Therefore, the analytical potential of the proposed nanosensor was evaluated by detecting biotin in urine and biotin tablets. This approach yielded satisfactory results because of the effective elimination of background fluorescence and light scattering from the sample matrix. This approach provides a practical method for biotin detection.