Zhao Jiangna, Deng Jianhui, Yi Yinhui, Li Haitai, Zhang Youyu, Yao Shouzhuo
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Talanta. 2014 Jul;125:372-7. doi: 10.1016/j.talanta.2014.03.031. Epub 2014 Mar 21.
In this work, label-free silicon quantum dots (SiQDs) were used as a novel fluorescence probe for the sensitive and selective detection of Cu(2+). The fluorescence of the SiQDs was effectively quenched by H2O2 from the reaction of ascorbic acid with O2, and hydroxyl radicals from Fenton reaction between H2O2 and Cu(+). The fluorescence intensity of SiQDs was quenched about 25% in 15 min after the addition of H2O2 (1mM). While the SiQDs was incubated with AA (1mM) and Cu(2+) (1 µM) under the same conditions, the fluorescence intensity of SiQDs decreased about 55%. Obviously, the recycling of Cu(2+) in the test system may lead to a dramatical decrease in the fluorescence of SiQDs. Under the optimized experimental conditions, the rate of fluorescence quenching of SiQDs was linearly dependent on the Cu(2+) concentration ranging from 25 to 600 nM with the limit of detection as low as 8 nM, which was much lower than that of existing methods. Moreover, the probe was successfully applied to the determination of Cu(2+) in different environmental water samples and human hair.
在本工作中，无标记硅量子点（SiQDs）被用作一种新型荧光探针，用于灵敏且选择性地检测Cu(2+)。抗坏血酸与O2反应产生的H2O2以及H2O2与Cu(+)之间芬顿反应产生的羟基自由基能有效猝灭SiQDs的荧光。加入H2O2（1mM）后15分钟内，SiQDs的荧光强度猝灭约25%。而在相同条件下将SiQDs与AA（1mM）和Cu(2+)（1µM）一起孵育时，SiQDs的荧光强度下降约55%。显然，测试体系中Cu(2+)的循环可能导致SiQDs荧光急剧下降。在优化的实验条件下，SiQDs的荧光猝灭速率与25至600 nM范围内的Cu(2+)浓度呈线性相关，检测限低至8 nM，远低于现有方法。此外，该探针成功应用于不同环境水样和人发中Cu(2+)的测定。
