title: Direct electrochemistry and voltammetric determination of midecamycin at a multi-walled carbon nanotube coated gold electrode.
abstract: Macrolide antibiotics generally shows slow electron-transfer rate and produces insensitive redox peaks at conventional electrodes. In this paper, we studied the electrochemical behavior of midecamycin, one of macrolide antibiotics, at a multi-walled carbon nanotube (MWNT) modified gold electrode. It was found that MWNT could adsorb midecamycin and promote its direct electron-transfer. Hence midecamycin exhibited a more sensitive anodic peak at the modified electrode. The electrochemical process showed the feature of a mixed-control system of diffusion and adsorption. Under the optimized conditions (i.e. pH 7.0 phosphate supporting electrolyte, 5 μl 0.5 mg ml⁻¹ multi-walled carbon nanotube suspension for Ø = 2.0 mm electrode, accumulation at -0.8 V for 150 s), the anodic peak current was linear to midecamycin concentration in the range of 5 × 10⁻⁷ to 2 × 10⁻⁵M, with a correlation coefficient of 0.998. For a 5×10⁻⁶ M midecamycin solution, ten repetitive measurements gave a relative standard deviation of 2.2%. This method was successfully applied to the determination of midecamycin in medicine tablet and the recovery was 97.5-104.0%.
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wan
authors.forename: Faqiong
authors.initials: F
authors.lastname: Zhao
authors.forename: Baizhao
authors.initials: B
authors.lastname: Zeng
mesh_terms: D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D006046:Gold