Core-shell like Cu₂O nanocubes enfolded with Co(OH)₂ on reduced graphene oxide for the amperometric detection of caffeine

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• 作者：Murugan Velmurugan ; Natarajan Karikalan ; Shen-Ming Chen…
• 关键词：Amperometry ; Cyclic voltammetry ; Rotating disc glassy carbon electrode ; FESEM ; Energy ; dispersive X ; ray spectroscopy ; Raman spectroscopy ; Beverage analysis ; Coffee powder ; Cola beverage ; Energy drinks
• 刊名：Microchimica Acta
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：183
• 期：10
• 页码：2713-2721
• 全文大小：1,547 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Analytical Chemistry
  Inorganic Chemistry
  Physical Chemistry
  Characterization and Evaluation Materials
  Monitoring, Environmental Analysis and Environmental Ecotoxicology
  
• 出版者：Springer Wien
• ISSN：1436-5073
• 卷排序：183

文摘

The authors report on the fabrication of Co(OH)₂-enfolded Cu₂O nanocubes on reduced graphene oxide (rGO), and the use of this material in an electrochemical caffeine sensor. The rGO/Cu₂O/Co(OH)₂ composite was characterized by X-ray powder diffraction pattern analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and Raman spectroscopy. A rotating disc glassy carbon electrode covered with the nanocomposite displays enhanced electrocatalytic activity towards the electro-oxidation of caffeine. The peak oxidation potential is at 1.4  V (vs. Ag/AgCl) and hence is strongly shifted to the negative side when compared to other modified electrodes. The calibration plot is linear in the 0.83 to 1200 μM concentration range, with a 0.4 μM detection limit (at a signal-to-noise ratio of 3). The modified electrode is sensitive, selective and stable. It was successfully applied to the determination of caffeine in (spiked) caffeine-containing beverages and coffee powder and gave recoveries that ranged from 95.7 to 98.3 %.