As(Ⅴ)催化H_2O_2氧化CdTe-Cys-QDs磷光传感器测定砷(Ⅴ)

Phosphorescence Sensor for the Detection of Trace As(Ⅴ) Based on As(Ⅴ) Catalyzing H_2O_2 Oxidize Cd Te-Cys-QDs

CdTe-Cys-QDs在聚酰胺素膜(PAM)上能发射强而稳定的室温磷光(RTP),并可被H_2O_2氧化为CdTe-CysQDs,结果使CdTe-Cys-QDs的表面新的缺陷增多,导致其磷光信号猝灭;更有趣的是As(Ⅴ)催化H_2O_2氧化CdTeCys-QDs导致体系的RTP剧烈猝灭,显示催化反应对RTP信号有放大效应.据此,提出一种测定痕量As(Ⅴ)的新CdTe-Cys-QDs磷光传感器.这种简便、快捷、灵敏(检出限(LD)=2.1×10^(-18)gmL^(-1))的磷光传感器用于人发和茶叶中痕量砷的测定结果与与AAS法相吻合.

The CdTe-Cys-QDs could emit strong and stable room temperature phosphorescence （RTP） on the polyamide membrane （PAM）, and it was oxidized by H：O2 to form the CdTe-Cys-QDs＇, resulting in the increasing of the defects on the surface of CdTe-Cys-QDs and the RTP signals to quench. More interestingly, As（V） can catalyze H2O2, to oxidize CdTe--Cys-QDs to quench of the RTP signal of system sharply, showing catalyzing reaction has signal amplifit.atioa effect on the RTP of system. Based on the above phenomena, a new CdTe-Cys-QDs phosphorescence sensor for the determination of trace As（V） has been developed. This simple, rapid and sensitive （The limit of detection （LOD） is 2.1 ×10-18 g mL-1） CdTe-Cys-QDs phosphorescence sensor has been utilized to detect As（V） in human hair, tea and water samples, and the results consisting with those obtained by atomic absorption spectrometry （AAS）.