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

• Published in: Sensors (Basel, Switzerland) Vol. 13; no. 7; pp. 8595 - 8611
• Main Authors: Hong, Jun, Zhao, Ying-Xue, Xiao, Bao-Lin, Moosavi-Movahedi, Ali, Ghourchian, Hedayatollah, Sheibani, Nader
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.07.2013; MDPI
• Subjects: Animals; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Carbon; Cattle; Chemicals; direct electrochemistry; Electrochemical Techniques - instrumentation; Electrochemical Techniques - methods; Electrodes; Electronic mail systems; Electrons; Fourier transforms; functionalized multi-walled carbon nanotubes; Glass - chemistry; Gold; Gold - chemistry; gold nanoparticles; Hemoglobin; Hemoglobins - chemistry; Hemoglobins - metabolism; Hydrogen peroxide; Hydrogen Peroxide - analysis; Hydrogen Peroxide - chemistry; Hydrogen-Ion Concentration; Immobilized Proteins - chemistry; Immobilized Proteins - metabolism; Limit of Detection; Metal Nanoparticles - chemistry; nanocomplex; Nanoparticles; Nanotechnology; Nanotubes, Carbon - chemistry; Proteins; Sensors; United States > US; China
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s130708595

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 (Kmapp) 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.