| Abstract
| - A novel multiwall carbon nanotubes (MWNTs)-based hybrid material with sandwich structure (DNA-Hb-MWNTs) was fabricated by alternative electrostatic assembly of hemoglobin (Hb) and DNA on MWNTs.TEM showed that such a nanocomposite behaved as an obvious core−shell structure. SEM proved the well-preserved 3-D structure of DNA-Hb-MWNTs assembled on an electrode. UV−vis and FTIR spectroscopywere used to monitor the assembly procession and also demonstrated that Hb had been sandwiched intoDNA and MWNTs without denaturation. A pair of stable and well-defined redox peaks of Hb with a formalpotential of about −0.298 V (vs Ag/AgCl) in a pH 6.0 phosphate buffer solution (PBS) were obtained at theDNA-Hb-MWNTs nanocomposite film-modified glassy carbon (GC) electrode (DNA-Hb-MWNT/GCelectrode). Compared with the Hb-MWNTs/GC electrode, the DNA-Hb-MWNTs/GC electrode exhibitedenhanced faradic current response, and the portion of the electroactive proteins had been greatly improved.Furthermore, the modified electrode also displayed good sensitivity, wide linear range, and long-term stabilityto the detection of hydrogen peroxide. Such an organized multicomponent biosensor platform may find widepotential applications in biosensors, biocatalysis, biomedical devices, and bioelectronics.
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