title: Electrogenerated chemiluminescence from a CdSe nanocrystal film and its sensing application in aqueous solution.
abstract: Electrogenerated chemiluminescence (ECL) of semiconductor quantum dots in aqueous solutions and its first sensing application were studied by depositing CdSe nanocrystals (NCs) on a paraffin-impregnated graphite electrode (PIGE). The CdSe nanocrystal thin film exhibited two ECL peaks at -1.20 (ECL-1) and -1.50 V (ECL-2) in pH 9.3, 0.1 M PBS during the cyclic sweep between 0 and -1.8 V at 20 mV s(-1). The electron-transfer reaction between individual electrochemically reduced nanocrystal species and oxidant coreactants such as H(2)O(2) and reduced dissolved oxygen led to ECL-1. When mass NCs packed densely in the film were reduced electrochemically, assembly of reduced nanocrystal species could react with coreactants to produce another ECL signal, ECL-2. ECL-1 showed higher sensitivity to the concentration of oxidant coreactants than ECL-2 and thus was used for ECL detection of coreactant, H(2)O(2). A linear response of ECL-1 to H(2)O(2) was observed in the concentration range of 2.5 x 10(-7)-6 x 10(-5) M with a detection limit of 1.0 x10(-7) M. The fabrication of 10 CdSe nanocrystal thin-film modified PIGEs displayed an acceptable reproducibility with a RSD of 1.18% obtained at H(2)O(2) level of 10 microM.
authors.affiliation: Department of Chemistry, Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Guizheng
authors.initials: G
authors.lastname: Zou
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry; D008163:Luminescent Measurements / Q000379:methods*; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D010232:Paraffin; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D008567:Membranes, Artificial; D018036:Selenium Compounds; D012996:Solutions; D014867:Water; D010232:Paraffin; C058667:cadmium selenide; D006861:Hydrogen Peroxide