Graphene‐amplified electrogenerated chemiluminescence of CdTe quantum dots for H2O2 sensing |
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Authors: | Zhonghui Wang Hongjie Song Huihui Zhao Yi Lv |
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Affiliation: | Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, , Chengdu, Sichuan, 610064 China |
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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 H2O2. 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 (H2O2 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 H2O2 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 H2O2 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. Copyright © 2012 John Wiley & Sons, Ltd. |
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Keywords: | electrogenerated chemiluminescence thiol‐capped CdTe quantum dots PDDA‐protected graphene H2O2 |
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