Cadmium telluride quantum dots as pH-sensitive probes for tiopronin determination

The pH-sensitive cadmium telluride (CdTe) quantum dots (QDs) were used as proton probes for tiopronin determination. Based on the fluorescence quenching of CdTe QDs caused by tiopronin, a simple, rapid and specific quantitative method was proposed. Under the optimal conditions, the calibration plot of ln(F-0/F) with concentration of tiopronin was linear in the range of 0.15-20 mu g mL(-1) (0.92-122.5 mu mol L-1) with correlation coefficient of 0.998. The limit of detection (LOD) (3 sigma/k) was 0.15 mu g mL(-1) (0.92 mu mol mL(-1)). The content of tiopronin in pharmaceutical tablet was determined by the proposed method and the result agreed with that obtained from the oxidation-reduction titration method and the claimed value. (c) 2008 Elsevier B.V. All rights reserved.