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Direct electrochemistry and electrocatalysis of hemoglobin in nafion/carbon nanochip film on glassy carbon electrode.
J Phys Chem B. 2009 Nov 26; 113(47):15445-54.JP

Abstract

The use of heat treated carbon nanofibers, known as carbon nanochips (CNCs) for the studies of the direct electrochemistry and electrocatalytic properties of heme proteins, is demonstrated. A glassy carbon electrode (GCE) was modified with CNCs, and hemoglobin (Hb) was immobilized on the modified electrode surface by casting a film of Hb. Nafion was employed to fix the CNCs and Hb tightly on the surface of the GCE. The modified electrode was characterized by scanning electron microscopy. Ultraviolet-visible and Fourier transform infrared spectroscopy showed that Hb immobilized in the CNC film remained in its native structure. Electrochemical impedance spectroscopy and cyclic voltammetry (CV) were employed for electrochemical studies. The results showed that the presence of CNCs in the film can greatly enhance the electrochemical response of Hb. A pair of well-defined reversible CV peaks was observed, and the formal potential of the heme Fe(III)/Fe(II) redox couple was found to be -253 mV [vs Ag/AgCl (saturated KCl)]. The apparent heterogeneous electron-transfer rate constant (k(s)) was estimated as 2.54 s(-1). The modified electrode showed excellent electrocatalytic behavior to hydrogen peroxide (H(2)O(2)), trichloroacetic acid, and sodium nitrite. H(2)O(2) had a linear current response from 0.5 to 30 microM (R(2) = 0.9997; n = 5) with a detection limit of 0.05 microM when the signal-to-noise ratio was 3 and the apparent Michaelis-Menten constant (K(m)(app)) was 21.55 microM. These values suggest that CNCs are the best matrix described so far for the development of biosensors, far superior to untreated carbon nanofibers. The direct immobilization of proteins onto the surface of CNCs is shown to be a highly efficient method for the development of a new class of very sensitive, stable, and reproducible electrochemical biosensors.

Authors+Show Affiliations

Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19883043

Citation

George, Sini, and Hian Kee Lee. "Direct Electrochemistry and Electrocatalysis of Hemoglobin in Nafion/carbon Nanochip Film On Glassy Carbon Electrode." The Journal of Physical Chemistry. B, vol. 113, no. 47, 2009, pp. 15445-54.
George S, Lee HK. Direct electrochemistry and electrocatalysis of hemoglobin in nafion/carbon nanochip film on glassy carbon electrode. J Phys Chem B. 2009;113(47):15445-54.
George, S., & Lee, H. K. (2009). Direct electrochemistry and electrocatalysis of hemoglobin in nafion/carbon nanochip film on glassy carbon electrode. The Journal of Physical Chemistry. B, 113(47), 15445-54. https://doi.org/10.1021/jp905690a
George S, Lee HK. Direct Electrochemistry and Electrocatalysis of Hemoglobin in Nafion/carbon Nanochip Film On Glassy Carbon Electrode. J Phys Chem B. 2009 Nov 26;113(47):15445-54. PubMed PMID: 19883043.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Direct electrochemistry and electrocatalysis of hemoglobin in nafion/carbon nanochip film on glassy carbon electrode. AU - George,Sini, AU - Lee,Hian Kee, PY - 2009/11/4/entrez PY - 2009/11/4/pubmed PY - 2010/1/23/medline SP - 15445 EP - 54 JF - The journal of physical chemistry. B JO - J Phys Chem B VL - 113 IS - 47 N2 - The use of heat treated carbon nanofibers, known as carbon nanochips (CNCs) for the studies of the direct electrochemistry and electrocatalytic properties of heme proteins, is demonstrated. A glassy carbon electrode (GCE) was modified with CNCs, and hemoglobin (Hb) was immobilized on the modified electrode surface by casting a film of Hb. Nafion was employed to fix the CNCs and Hb tightly on the surface of the GCE. The modified electrode was characterized by scanning electron microscopy. Ultraviolet-visible and Fourier transform infrared spectroscopy showed that Hb immobilized in the CNC film remained in its native structure. Electrochemical impedance spectroscopy and cyclic voltammetry (CV) were employed for electrochemical studies. The results showed that the presence of CNCs in the film can greatly enhance the electrochemical response of Hb. A pair of well-defined reversible CV peaks was observed, and the formal potential of the heme Fe(III)/Fe(II) redox couple was found to be -253 mV [vs Ag/AgCl (saturated KCl)]. The apparent heterogeneous electron-transfer rate constant (k(s)) was estimated as 2.54 s(-1). The modified electrode showed excellent electrocatalytic behavior to hydrogen peroxide (H(2)O(2)), trichloroacetic acid, and sodium nitrite. H(2)O(2) had a linear current response from 0.5 to 30 microM (R(2) = 0.9997; n = 5) with a detection limit of 0.05 microM when the signal-to-noise ratio was 3 and the apparent Michaelis-Menten constant (K(m)(app)) was 21.55 microM. These values suggest that CNCs are the best matrix described so far for the development of biosensors, far superior to untreated carbon nanofibers. The direct immobilization of proteins onto the surface of CNCs is shown to be a highly efficient method for the development of a new class of very sensitive, stable, and reproducible electrochemical biosensors. SN - 1520-5207 UR - https://www.unboundmedicine.com/medline/citation/19883043/Direct_electrochemistry_and_electrocatalysis_of_hemoglobin_in_nafion/carbon_nanochip_film_on_glassy_carbon_electrode_ L2 - https://doi.org/10.1021/jp905690a DB - PRIME DP - Unbound Medicine ER -