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 (R RMS) 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.

Tunable Semicrystalline Thin Film Cellulose Substrate for High-Resolution, In-Situ AFM Characterization of Enzymatic Cellulose Degradation

“…The corresponding time scales to remove a crystalline feature are highlighted in Figure 6b by blue and red arrows for TrCel6A and TrCel6A + TrCel7A, respectively. The timeresolved evaluation of RMS surface roughness 45 reveals a slow increase during TrCel7A exposure followed by strong increase after adding TrCel7A, which correlates well with localized AFM results and volume loss data (Figure 6) due to the synergistic activity (see Figure S3).…”

Sequence Programming with Dynamic Boronic Acid/Catechol Binary Codes

“…Additionally, topological height increases due to complexation was visualized by atomic force microscopy (Figure S19). 43…”

“…Additionally, topological height increases due to complexation was visualized by atomic force microscopy (Figure S19). 43 In summary, we have demonstrated, to the best of our knowledge, the first application of boronic acid chemistry in molecular sequence programming under physiological conditions. By combining the recognition and binding customization of boronic acid/catechol chemistry with a peptide scaffold, synthetic binary codes were created, in which binding and dynamic displacement was directed in a predictable and logical manner.…”

Removal of Cr 6+ ions from water by electrosorption on modified activated carbon fibre felt

“…By contrast, if the plate spacing is too large, it takes a long time for the ions to reach and adsorb onto the electric double layer due to the long distance of ion diffusion between the electrodes and low turbulivity. Moreover, the electrode has limited effect on distant ions and cannot adsorb them onto its surface [ 35 ]. In summary, 10 mm was the optimal plate spacing for electrosorption of Cr 6+ by the modified ACFF.…”