title: A highly sensitive hydrogen peroxide amperometric sensor based on MnO2-modified vertically aligned multiwalled carbon nanotubes.
abstract: In this report, a highly sensitive amperometric sensor based on MnO(2)-modified vertically aligned multiwalled carbon nanotubes (MnO(2)/VACNTs) for determination of hydrogen peroxide (H(2)O(2)) was fabricated by electrodeposition. The morphology of the nanocomposite was characterized by scanning electron microscopy, energy-dispersive X-ray spectrometer and X-ray diffraction. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were applied to investigate the electrochemical properties of the MnO(2)/VACNTs nanocomposite electrode. The mechanism for the electrochemical reaction of H(2)O(2) at the MnO(2)/VACNTs nanocomposite electrode was also discussed. In borate buffer (pH 7.8, 0.20 M), the MnO(2)/VACNTs nanocomposite electrode exhibits a linear dependence (R=0.998) on the concentration of H(2)O(2) from 1.2 x 10(-6)M to 1.8 x 10(-3)M, a high sensitivity of 1.08 x 10(6) microA M(-1) cm(-2) and a detection limit of 8.0 x 10(-7) M (signal/noise=3). Meanwhile, the MnO(2)/VACNTs nanocomposite electrode is also highly resistant towards typical inorganic salts and some biomolecules such as acetic acid, citric acid, uric acid and D-(+)-glucose, etc. In addition, the sensor based on the MnO(2)/VACNTs nanocomposite electrode was applied for the determination of trace of H(2)O(2) in milk with high accuracy, demonstrating its potential for practical application.
authors.affiliation: Nano Science Research Center, School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640, Guangdong, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Min-Ling
authors.initials: ML
authors.lastname: Ye
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Yu
authors.forename: Wei-De
authors.initials: WD
authors.lastname: Zhang
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D037742:Nanotubes, Carbon; D010087:Oxides; D006861:Hydrogen Peroxide; C016552:manganese dioxide