In Situ Spectroelectrochemical Investigations of Electrode-Confined Electron-Transferring Proteins and Redox Enzymes

Abstract

This perspective analyzes recent advances in the spectroelectrochemical investigation of redox proteins and enzymes immobilized on biocompatible or biomimetic electrode surfaces. Specifically, the article highlights new insights obtained by surface-enhanced resonance Raman (SERR), surfaceenhanced infrared absorption (SEIRA), protein film infrared electrochemistry (PFIRE), polarization modulation infrared reflection−absorption spectroscopy (PMIRRAS), Forster resonance energy transfer (FRET), X-ray absorption spectroscopy (XAS), electron paramagnetic resonance (EPR), and differential electrochemical mass spectrometry (DMES)-based spectroelectrochemical methods on the structure, orientation, dynamics, and reaction mechanisms for a variety of immobilized species. This includes small heme and copper electron shuttling proteins, large respiratory complexes, hydrogenases, multicopper oxidases, alcohol dehydrogenases, endonucleases, NO-reductases, and dye decolorizing peroxidases, among other enzymes. Finally, I discuss the challenges and foreseeable future developments toward a better understanding of the functioning of these complex macromolecules and their exploitation in technological devices.

Anomalously Small Reorganization Energy of the Half Redox Reaction of Azurin

“…The conditions of electrochemical experiment, where the protein is immobilized on the SAM coating the metal electrode, can be substantially distinct from the solution simulations carried out here. 62,90 The hydration shell around the active site is grossly reduced by attachment, and fluctuations of the protein might become the leading component of the entire fluctuation spectrum of the thermal bath. Furthermore, from the fundamental perspective, it is the frustrated protein scaffold that is expected to demonstrate nonergodic statistics of electrostatic fluctuations and one wants to know the extent of separation between λ St and λ for the protein component alone.…”

A review on the contamination of SARS-CoV-2 in water bodies: Transmission route, virus recovery and recent biosensor detection techniques

“… Device reproducibility with EC-SERS substrates; complexity in data analysis and interpretation; appropriate design needed for on-site analysis. [ 171 , 172 ] …”

Infrared spectroscopic monitoring of solid-state processes

“…Therefore, this review will be focused on mid-infrared spectroscopic monitoring of chemical and physical processes occurring in solid-state systems, relevant to the understanding of materials. Although the various applications of IR spectroscopy to monitor solid-state processes are covered by numerous reviews, 1–10 the author's intention is to bring to focus some specific applications and perspectives, that have so far remained somewhat out of focus. Numerous recent excellent reviews on the specific applications of IR spectroscopy are available, for example on the applications of IR spectroscopy in monitoring liquids 2,11–13 or gaseous systems, 14–16 as well as interfaces.…”