Layer-by-layer construction of multi-walled carbon nanotubes, zinc oxide, and gold nanoparticles integrated composite electrode for nitrite detection
✍ Scribed by Ai-Jing Lin; Ying Wen; Li-Jun Zhang; Bin Lu; Yan Li; Ying-Zhi Jiao; Hai-Feng Yang
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 686 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
A novel composite electrode of Au/ZnO/MWCNTs/GC has been constructed for the electrochemical detection of nitrite, where ZnO thin film and Au nanoparticles are electrodeposited through layer-by-layer onto MWCNTs/GC substrate. The resulting electrode is characterized by scanning electron microscopy and energy-dispersed X-ray spectroscopy. Its electrocatalytic activity toward the electro-oxidation of nitrite has been examined and compared to various modified electrodes, including MWCNTs/GC, Au/ZnO/GC, Au/MWCNTs/GC, and ZnO/MWCNTs/GC via cyclic voltammetry. The electrodeposition time for ZnO and the Au loading amount together with the solution pH are investigated to achieve optimal conditions for the electrode fabrication and nitrite detection. Linear relationship between current response and nitrite concentration is observed in the range from 7.8 × 10 -7 to 4.0 × 10 -4 M and the limit of the detection is 4.0 × 10 -7 M (S/N = 3). The influence of various anions and cations on the nitrite detection has been studied. The proposed method is also employed for the determination of nitrite in real samples.