Label-free silicon quantum dots as fluorescent probe for selective and sensitive detection of copper ions.
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.
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.
Jiangna
J
Zhao
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.
Jianhui
J
Deng
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.
Yinhui
Y
Yi
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.
Haitai
H
Li
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. Electronic address: zhangyy@hunnu.edu.cn.
Youyu
Y
Zhang
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.
Shouzhuo
S
Yao
D001205:Ascorbic Acid / Q000737:chemistry; D015374:Biosensing Techniques; D003300:Copper / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006197:Hair / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D007477:Ions; D007501:Iron / Q000737:chemistry; D057230:Limit of Detection; D046529:Microscopy, Electron, Transmission; D045663:Quantum Dots; D015203:Reproducibility of Results; D015398:Signal Transduction; D013050:Spectrometry, Fluorescence; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis
C045076:Fenton's reagent; D005456:Fluorescent Dyes; D007477:Ions; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical; D003300:Copper; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid
Ascorbic acid; Cu(2+); Fenton reaction; Fluorescence quenching; H(2)O(2); Silicon quantum dots