CdTe quantum dot as a fluorescence probe for vitamin B12 in dosage form

We here report the CdTe quantum dot (CdTe QDs)-based sensor for probing vitamin B-12 derivatives in aqueous solution. In this paper, simple and sensitive fluorescence quenching measurements has been employed. The Stern-Volmer constant (K-sv), quenching rate constant (k(q)) and binding constant (K) were rationalized from fluorescence quenching measurement. Furthermore, the fluorescence resonance energy transfer (FRET) mechanism was discussed. This method was applicable over the concentration ranging from 1 to 14 mu g/mL (VB12) with correlation coefficient of 0.993. The limit of detection (LOD) of VB12 was found to be 0.15 mu g/mL. Moreover, the present approach opens a simple pathway for developing cost-effective, sensitive and selective QD-based fluorescence sensors/probes for biologically significant VB12 in pharmaceutical sample with mean recoveries in the range of 100-102.1%. (C) 2013 Elsevier B.V. All rights reserved.