Determination of vanadium(V) with CdTe quantum dots as fluorescent probes.

CdTe quantum dots (QDs) were modified with thioglycolic acid (TGA) and synthesized in aqueous medium. The optimum fluorescence intensity was found to be at pH 6.24 with a CdTe QDs concentration of 4.96 x 10(-7) mol L(-1). The quenched fluorescence intensity of CdTe QDs is linearly proportional to V(V) concentration from 10 to 200 ng mL(-1) with correlation coefficient R = 0.9985. The limit of detection for V(V) was 2.07 ng mL(-1). The proposed method was successfully applied to the analysis of trace amounts of V(V) in water samples with recovery of 96.5-101.8%, and the results were in good agreement with those of electrothermal atomic absorption spectrometry.