title: A reagentless biosensor of nitric oxide based on direct electron transfer process of cytochrome c on multi-walled carbon nanotube.
abstract: Direct electron transfer between Cytochrome c (Cyt.c) and electrode can be achieved through immobilizing Cyt.c on the surface of multi-walled carbon nanotubes (MWNTs). Under the condition of cyclic potential scans, Cyt.c can be adsorbed on the surface of MWNTs that were modified on a glassy carbon (GC) electrode to form an approximate monolayer. The redox characteristic and bioactivity of Cyt.c could be remained after it was adsorbed on MWNTs' surface. This provides a way to construct a new biosenser based on the activity of Cyt.c. Further investigation displayed that Cyt.c adsorbed on MWNTs showed an enzyme-like activity to catalyze the reduction of nitric oxide (NO). Due to catalyzing by Cyt.c, the reduction of NO in aqueous solution was achieved, which reductive potential appeared at -0.747V (vs. SCE). The peak currents were linearly proportional to concentration of NO in the range from 2 to 48 micromol/l with a limit of detection of 1.3 microM. The biosensor showed a good stability and excellent repeatability.
authors.affiliation: Anhui Key Laboratory of Functional molecular Solids, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, People's Republic of China. gczhao@mail.ahnu.edu.cn
authors.forename: Guang-Chao
authors.initials: GC
authors.lastname: Zhao
authors.forename: Zheng-Zhi
authors.initials: ZZ
authors.lastname: Yin
authors.forename: Xian-Wen
authors.initials: XW
authors.lastname: Wei
mesh_terms: D015374:Biosensing Techniques; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000737:chemistry*; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D009569:Nitric Oxide; D045304:Cytochromes c