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

Tasviri, M. (Mahboubeh) ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.3184/146867812X13323491552144
  3. Abstract:
  4. Horseradish peroxidase (HRP) was successfully immobilized on amine functionalized TiO2-coated multiwalled carbon nanotubes (NH2 – TiO2 – CNTs) by a convenient and efficient method. Electrochemical impedance spectroscopy, cyclic voltammetry and amperometry were applied to characterize the HRP/NH2 – TiO2 – CNT nano-composite. These techniques showed that the NH2 – TiO2 – 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 = NH2 – TiO2 – CNTs modified electrode exhibited a pair of quasi-reversible peaks with a peak-to-peak separation (ΔEp) of 70.6 mV and a formal potential (E 0′) of 367.65 mV (versus Ag = AgCl) in phosphate buffer solution. The charge transfer coefficient (α) and the apparent charge transfer rate constant (ks) were found to be 0.34 and 2.08 s1, respectively. The prepared biosensor responded to H2 O2 with a linear range, detection limit, sensitivity and response time of 1.0 × 109 to 1.0 × 107 M, 0.786 nM, 28.4 m A nM–1 and 3 s, respectively
  5. Keywords:
  6. Carbon nanotubes ; Direct electrochemistry ; Horseradish peroxidase ; Hydrogen peroxide ; Titanium dioxide
  7. Source: Progress in Reaction Kinetics and Mechanism ; Volume 37, Number 2 , 2012 , pp. 161-172
  8. URL: http://www.ingentaconnect.com/content/stl/prk/2012/00000037/00000002/art00004