%0 Journal Article
%T Mechanisms for the Direct Electron Transfer of Cytochrome c Induced by Multi-Walled Carbon Nanotubes
%A Hua-Zhang Zhao
%A Qian Du
%A Zhen-Shan Li
%A Qin-Zheng Yang
%J Sensors
%D 2012
%I MDPI AG
%R 10.3390/s120810450
%X Multi-walled carbon nanotube (MWCNT)-modified electrodes can promote the direct electron transfer (DET) of cytochrome c (Cyt c). There are several possible mechanisms that explain the DET of Cyt c. In this study, several experimental methods, including Fourier transform infrared spectroscopy, circular dichroism, ultraviolet-visible absorption spectroscopy, and electron paramagnetic resonance spectroscopy were utilized to investigate the conformational changes of Cyt c induced by MWCNTs. The DET mechanism was demonstrated at various nano-levels: secondary structure, spatial orientation, and spin state. In the presence of MWCNTs, the secondary structure of Cyt c changes, which exposes the active site, then, the orientation of the heme is optimized, revolving the exposed active center to the optimum spatial orientation for DET; and finally, a transition of spin states is induced, providing relatively high energy and a more open microenvironment for electron transfer. These changes at different nano-levels are closely connected and form a complex process that promotes the electron transfer of Cyt c.
%K direct electron transfer (DET)
%K cytochrome c (Cyt c)
%K multi-walled carbon nanotube (MWCNT)
%K secondary structure
%U http://www.mdpi.com/1424-8220/12/8/10450