谷胱甘肽稳定的CdTe量子点荧光猝灭法测定痕量过氧化氢

以谷胱甘肽稳定的CdTe量子点作为荧光探针,基于荧光猝灭法对过氧化氢进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响。实验结果表明,在pH=7.2的Na2HPO4-NaH2PO4缓冲液中,反应时间为15min,过氧化氢浓度为1.0×10-6～3.0×10-5 mol/L范围时,其线性回归方程为△F=9.78+7.56c(10-6 mol/L),线性相关系数和检测限分别为0.9992和1.27×10-8 mol/L。谷胱甘肽稳定的CdTe量子点荧光猝灭法已用于水样的测定,回收率在96%～103%之间,相对标准偏差RSD不大于3.3%,结果令人满意。

Determination of Trace Hydrogen Peroxide by Fluorescence Quenching Method of Glutathione-capped CdTe Quantum Dots

By using glutathione-capped CdTe quantum dots(QDs) as a fluorescent(PL) probe,a new fluorescence quenching method was developed to quantitatively determine hydrogen peroxide based on PL quenching effect of CdTe QDs.The influences of buffer solution,QDs concentration and incubation time on the fluorescence behavior of QDs were investigated.The results indicated that in a Na2HPO4-NaH2PO4 buffer solution at pH=7.2 and with 15 min incubation,the determined concentration of hydrogen peroxide was in the ranges of 1.0×10-6~3.0×10-5 mol/L.The fluorescence intensity of CdTe QDs and the concentration of hydrogen peroxide follow the linearly fitted equation as: △F=9.78+7.56c(10-6 mol/L) with the correlation coefficient of 0.9992.The detection limit was 1.27×10-8 mol/L.The fluorescence quenching method of glutathione-capped CdTe QDs has been applied to analyze water samples.The recoveries were between 96% to 103% and relative standard deviation of the method was less than 3.3%,which were satisfactory.