title: Real-time dynamic adsorption processes of cytochrome c on an electrode observed through electrochemical high-speed atomic force microscopy.
abstract: An understanding of dynamic processes of proteins on the electrode surface could enhance the efficiency of bioelectronics development and therefore it is crucial to gain information regarding both physical adsorption of proteins onto the electrode and its electrochemical property in real-time. We combined high-speed atomic force microscopy (HS-AFM) with electrochemical device for simultaneous observation of the surface topography and electron transfer of redox proteins on an electrode. Direct electron transfer of cytochrome c (cyt c) adsorbed on a self-assembled monolayers (SAMs) formed electrode is very attractive subject in bioelectrochemistry. This paper reports a real-time visualization of cyt c adsorption processes on an 11-mercaptoundecanoic acid-modified Au electrode together with simultaneous electrochemical measurements. Adsorbing cyt c molecules were observed on a subsecond time resolution simultaneously with increasing redox currents from cyt c using EC-HS-AFM. The root mean square roughness (RRMS) from the AFM images and the number of the electrochemically active cyt c molecules adsorbed onto the electrode (Γ) simultaneously increased in positive cooperativity. Cyt c molecules were fully adsorbed on the electrode in the AFM images when the peak currents were steady. This use of electrochemical HS-AFM significantly facilitates understanding of dynamic behavior of biomolecules on the electrode interface and contributes to the further development of bioelectronics.
authors: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Kouta
authors: K
authors: Takeda
authors: Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa, Japan; Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors: Takayuki
authors: T
authors: Uchihashi
authors: Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors: Hiroki
authors: H
authors: Watanabe
authors: Department of Biomaterials Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors: Takuya
authors: T
authors: Ishida
authors: Department of Biomaterials Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors: Kiyohiko
authors: K
authors: Igarashi
authors: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan; Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors: Nobuhumi
authors: N
authors: Nakamura
authors: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Hiroyuki
authors: H
authors: Ohno
mesh_terms: D000327:Adsorption; D000818:Animals; D045304:Cytochromes c / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D005227:Fatty Acids / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D011487:Protein Conformation; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013997:Time Factors
chemical_list: C505222:11-mercaptoundecanoic acid; D005227:Fatty Acids; D013438:Sulfhydryl Compounds; D006046:Gold; D045304:Cytochromes c