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Horseradish peroxidase immobilization on amine functionalized carbon nanotubes: Direct electrochemistry and bioelectrocatalysis

Tasviri, M ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.3184/146867812X13323491552144
  3. Publisher: 2012
  4. Abstract:
  5. Horseradish peroxidase (HRP) was successfully immobilized on amine functionalized TiO 2-coated multiwalled carbon nanotubes (NH 2-TiO 2-CNTs) by a convenient and efficient method. Electrochemical impedance spectroscopy, cyclic voltammetry and amperometry were applied to characterize the HRP/NH 2-TiO 2-CNT nano-composite. These techniques showed that the NH 2-TiO 2-CNTs greatly enhance the electron transfer between HRP and the modified electrode. Owing to the redox reaction of the electroactive centre of HRP, the HRP/NH 2-TiO 2-CNTs modified electrode exhibited a pair of quasi-reversible peaks with a peak-to-peak separation (ΔE p) of 70.6mV and a formal potential (E 0′) of -367.65mV (versus Ag/AgCl) in phosphate buffer solution. The charge transfer coefficient (α) and the apparent charge transfer rate constant (k s) were found to be 0.34 and 2.08 s -1, respectively. The prepared biosensor responded to H 2O 2 with a linear range, detection limit, sensitivity and response time of 1.0×10 -9 to 1.0×10 -7 M, 0.786 nM, 28.4 μA nM -1 and 3 s, respectively
  6. Keywords:
  7. Ag/AgCl ; Amperometry ; Bioelectrocatalysis ; Charge transfer coefficient ; Charge-transfer rate ; Detection limits ; Direct electrochemistry ; Electroactive ; Electron transfer ; Formal potential ; Functionalized ; Functionalized carbon nanotubes ; Horse-radish peroxidase ; Linear range ; Modified electrodes ; Peak-to-peak separation ; Phosphate buffer solutions ; Quasi-reversible peak ; TiO ; Biosensors ; Carbon nanotubes ; Charge transfer ; Cyclic voltammetry ; Electrochemical impedance spectroscopy ; Electrochemistry ; Hydrogen peroxide ; Multiwalled carbon nanotubes (MWCN) ; Organic compounds ; Rate constants ; Redox reactions ; Titanium dioxide
  8. Source: Progress in Reaction Kinetics and Mechanism ; Volume 37, Issue 2 , May , 2012 , Pages 161-172 ; 14686783 (ISSN)
  9. URL: http://stl.publisher.ingentaconnect.com/search/article?option1=tka&value1=Horseradish+peroxidase+immobilization&operator9=AND&option9=publications&value9=stl&sortDescending=true&sortField=default&pageSize=10&index=1