title: Graphene-amplified electrogenerated chemiluminescence of CdTe quantum dots for H2O2 sensing.
abstract: Electrogenerated chemiluminescence (ECL) of thiol-capped CdTe quantum dots (QDs) in aqueous solution was greatly enhanced by PDDA-protected graphene (P-GR) film that were used for the sensitive detection of H2 O2 . When the potential was cycled between 0 and -2.3 V, two ECL peaks were observed at -1.1 (ECL-1) and -1.4 V (ECL-2) in pH 11.0, 0.1 M phosphate buffer solution (PBS), respectively. The electron-transfer reaction between individual electrochemically-reduced CdTe nanocrystal species and oxidant coreactants (H2 O2 or reduced dissolved oxygen) led to the production of ECL-1. While mass nanocrystals packed densely in the film were reduced electrochemically, assembly of reduced nanocrystal species reacted with coreactants to produce an ECL-2 signal. ECL-1 showed higher sensitivity for the detection of H2 O2 concentrations than that of ECL-2. Further, P-GR film not only enhanced ECL intensity of CdTe QDs but also decreased its onset potential. Thus, a novel CdTe QDs ECL sensor was developed for sensing H2O2. Light intensity was linearly proportional to the concentration of H2 O2 between 1.0 × 10(-5) and 2.0 x 10(-7) mol L(-1) with a detection limit of 9.8 x 10(-8) mol L(-1). The P-GR thin-film modified glassy carbon electrode (GCE) displayed acceptable reproducibility and long-term stability.
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China.
authors.forename: Zhonghui
authors.initials: Z
authors.lastname: Wang
authors.forename: Hongjie
authors.initials: H
authors.lastname: Song
authors.forename: Huihui
authors.initials: H
authors.lastname: Zhao
authors.forename: Yi
authors.initials: Y
authors.lastname: Lv
mesh_terms: D002104:Cadmium / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D057230:Limit of Detection; D049449:Luminescence; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D045663:Quantum Dots / Q000737:chemistry*; D015203:Reproducibility of Results; D013691:Tellurium / Q000737:chemistry
chemical_list: D002104:Cadmium; D006108:Graphite; D006861:Hydrogen Peroxide; D013691:Tellurium