Direct Electrochemistry of Hemoglobin Immobilized on a Functionalized Multi-Walled Carbon Nanotubes and Gold Nanoparticles Nanocomplex-Modified Glassy Carbon Electrode

Sensors

Jun Hong¹  Ying-Xue Zhao¹  Bao-Lin Xiao¹  Ali Akbar Moosavi-Movahedi²  Hedayatollah Ghourchian² 

[1] School of Life Sciences, Henan University, JinMing Road, Kaifeng 475000, China; E-Mails:;Institute of Biochemistry and Biophysics, University of Tehran, Enquelab Avenue, P.O. Box 13145-1384, Tehran, Iran; E-Mail:

关键词: hemoglobin;    direct electrochemistry;    functionalized multi-walled carbon nanotubes;    gold nanoparticles;    nanocomplex;   

DOI  :  10.3390/s130708595

来源: mdpi

【 摘 要 】

Direct electron transfer of hemoglobin (Hb) was realized by immobilizing Hb on a carboxyl functionalized multi-walled carbon nanotubes (FMWCNTs) and gold nanoparticles (AuNPs) nanocomplex-modified glassy carbon electrode. The ultraviolet-visible absorption spectrometry (UV-Vis), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) methods were utilized for additional characterization of the AuNPs and FMWCNTs. The cyclic voltammogram of the modified electrode has a pair of well-defined quasi-reversible redox peaks with a formal potential of −0.270 ± 0.002 V (vs. Ag/AgCl) at a scan rate of 0.05 V/s. The heterogeneous electron transfer constant (ks) was evaluated to be 4.0 ± 0.2 s⁻¹. The average surface concentration of electro-active Hb on the surface of the modified glassy carbon electrode was calculated to be 6.8 ± 0.3 × 10⁻¹⁰ mol cm⁻². The cathodic peak current of the modified electrode increased linearly with increasing concentration of hydrogen peroxide (from 0.05 nM to 1 nM) with a detection limit of 0.05 ± 0.01 nM. The apparent Michaelis-Menten constant (K_m^app) was calculated to be 0.85 ± 0.1 nM. Thus, the modified electrode could be applied as a third generation biosensor with high sensitivity, long-term stability and low detection limit.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.