Electrogenerated chemiluminescence from thiol-capped CdTe quantum dots and its sensing application in aqueous solution.
In this paper, the electrogenerated chemiluminescence (ECL) from thiol-capped CdTe quantum dots (QDs) was reported. The ECL emission was occurred at -1.1 V and reached a maximum value at -2.4 V when the potential was cycled between 0.0 and -2.5 V. The reduced species of CdTe QDs could react with the coreactants to produce the ECL emission. The CdTe QD concentration (6.64x10(-7) mol L(-1)) of ECL is lower than that (1.0x10(-3) mol L(-1)) of chemiluminescence (CL). Based on the enhancement of light emission from thiol-capped CdTe QDs by H2O2 in the negative electrode potential, a novel method for the determination of H2O2 was developed. The light intensity was linearly proportional to the concentration of H2O2 between 2.0x10(-7) and 1.0x10(-5) mol L(-1) with a detection limit of 6.0x10(-8) mol L(-1). Compared with most of previous reports, the proposed method has higher sensitivity for the determination of H2O2. In addition, the ECL spectrum of thiol-capped CdTe QDs exhibited a peak at around 620 nm, which was substantially red shifted from the photoluminescence (PL) spectrum, suggesting the surface states play an important role in this ECL process.
Han
Heyou
H
College of Science, State Key Laboratory of Agricultural Microbiology, MOA Key Laboratory of Food Safety Evaluation, Huazhong Agricultural University, Wuhan 430070, PR China. hyhan@mail.hzau.edu.cn <hyhan@mail.hzau.edu.cn>
Sheng
Zonghai
Z
Liang
Jiangong
J
D019187:Cadmium Compounds / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008027:Light; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D045663:Quantum Dots; D012680:Sensitivity and Specificity; D012996:Solutions; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D019187:Cadmium Compounds; D012996:Solutions; D013438:Sulfhydryl Compounds; D014867:Water; D006861:Hydrogen Peroxide; D013691:Tellurium; C028337:cadmium telluride