title: Analyzing the catalytic processes of immobilized redox enzymes by vibrational spectroscopies.
abstract: Analyzing the structure and function of redox enzymes attached to electrodes is a central challenge in many fields of fundamental and applied life science. Electrochemical techniques such as cyclic voltammetry which are routinely used do not provide insight into the molecular structure and reaction mechanisms of the immobilized proteins. Surface-enhanced infrared absorption (SEIRA) and surface-enhanced resonance Raman (SERR) spectroscopy may fill this gap, if nanostructured Au or Ag are used as conductive support materials. In this account, we will first outline the principles of the methodology including a description of the most important strategies for biocompatible protein immobilization. Subsequently, we will critically review SERR and SEIRA spectroscopic approaches to characterize the protein and active site structure of the immobilized enzymes. Special emphasis is laid on the combination of surface-enhanced vibrational spectroscopies with electrochemical methods to analyze equilibria and dynamics of the interfacial redox processes. Finally, we will assess the potential of SERR and SEIRA spectroscopy for in situ investigations on the basis of the first promising studies on human sulfite oxidase and hydrogenases under turnover conditions.
authors.affiliation: Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany.
authors.forename: Murat
authors.initials: M
authors.lastname: Sezer
authors.forename: Diego
authors.initials: D
authors.lastname: Millo
authors.forename: Inez M
authors.initials: IM
authors.lastname: Weidinger
authors.forename: Ingo
authors.initials: I
authors.lastname: Zebger
authors.forename: Peter
authors.initials: P
authors.lastname: Hildebrandt
mesh_terms: D015374:Biosensing Techniques; D057075:Enzyme Assays; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D004800:Enzymes, Immobilized; D012834:Silver