1. Cu(III)-independent oxidation and sensing of glucose on multi-layer stacked copper nanoparticles.
- Author
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Xia, Lun-Peng, Liu, Lu, Deng, Ning, Zhu, Yan-Wu, and He, Jian-Bo
- Subjects
COPPER oxidation ,GLUCOSE ,NANOPARTICLES ,ELECTROPLATING ,ELECTRIC batteries ,ELECTROLYSIS - Abstract
A highly sensitive electrode for sensing glucose has been fabricated by electropolymerization of 2-amino-5-mercapto-1,3,4-thiadiazole on a solid carbon paste substrate, and subsequent electrodeposition of multi-layer stacked copper particles as an outer surface. The individual copper particles are characterized by a large number of edges and corners of crystallites. Their preferred orientation {111} is parallel to the electrode surface. The conductive polymer interlayer results in an increase of the particle nucleation density and a further decrease of the polarization overpotential for direct (enzyme-free) oxidation of glucose in 0.1 M NaOH solution. A well-shaped voltammetric peak can be observed at around 0.3-0.5 V (vs. SCE, depending on scan rate) that is due to glucose oxidation. This potential is much lower than the one required for Cu(III) formation. A bulk electrolysis experiment using a thin-layer electrochemical cell confirmed the assumption that that glucose undergoes 2-electron oxidation. The mechanism of glucose oxidation in the absence of Cu(III) is discussed. The electrode exhibits a very high sensitivity (slope) of 3.31 mA cm mM, and the detection limit is 2 μM (at an SNR of 3). Features of the new sensor include the ease of fabrication, its high stability and good selectivity. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
- Published
- 2015
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