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Single-crystal voltammetry and in situ scanning tunnelling microscopy of redox metalloproteins: Bioelectrochemistry towards the single-molecule level
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Journal of Inorganic Biochemistry 96 (2003)
Single-Crystal Voltammetry and In Situ Scanning Tunnelling Microscopy of Redox Metalloproteins: Bioelectrochemistry towards the Single-Molecule Level Jens Ulstrup, Department of Chemistry, Technical University of Denmark, Denmark Jingdong Zhang, Department of Chemistry, Technical University of Denmark, Denmark Allan G Hansen, Department of Chemistry, Technical University of Denmark, Denmark Hainer Wackerbarth, Department of Chemistry, Technical Universi@ of Denmark, Denmark Hans EM Christensen, Department of Chemistry, Technical University of Denmark, Denmark Diffusion controlled and film voltammetry are established techniques to address thermodynamic and interfacial electron transfer of both small redox metalloproteins and multi-centre redox metalloenzymes. Introduction of single-crystal, atomically planar metal electrode surfaces and in situ scanning tunnelling microscopy (STM) directly in aqueous buffer under electrochemical potential control, has, however, added new perspectives to protein bioelectrochemistry. Single-crystal electrodes enhance significantly voltammetric and interfacial capacitance sensitivity, and in situ STM addresseseven single biomolecules in electron transporting action. Other state-of-the-art surface science tools such as microcantilever sensor techniques and X-ray photoelectron spectroscopy have supported this. We overview studies in our group based on single-crystal voltammetry, interfacial capacitance, X-ray photoelectron spectroscopy,microcantilever sensortechniques, and in situ STM of several redox proteins on functionally modified Au( 11l)electrode surfaces. The proteins are: Pseudomonas aeruginosa azurin, Saccharomyces cerevisiae cytochrome c, Pyrococcus furiosis [3Fe-4S] ferredoxin, and the trimeric blue copper oxidase Achromobacter xylosoxidans Cu-nitrite reductase, as shown in Figure I. The data point to new ways of mapping and controlling redox metalloprotein orientation and function at well-characterised electrochemical surfaces. This is important in future electrochemical biosensor design towards the single-molecule level. Zhang, J.; Chi, Q.; Kuznetsov, A.M.; Hansen, A.G.; Wackerbarth, H.; Christensen, H.E.M.; Andersen, J.E.T.; Ulstrup, J. J. Phys. Chem. B 2002,106,1131-1152. Fig. 1 Molecular structures. In the left column the Cu-proteins azurin (top) and the enzyme nitrite reductase (bottom). In the right column the iron containing (yeast) cytochrome c (top) and ferredoxin (bottom)
Journal of Inorganic Biochemistry 96 (2003)
Single-Crystal Voltammetry and In Situ Scanning Tunnelling Microscopy of Redox Metalloproteins: Bioelectrochemistry towards the Single-Molecule Level Jens Ulstrup, Department of Chemistry, Technical University of Denmark, Denmark Jingdong Zhang, Department of Chemistry, Technical University of Denmark, Denmark Allan G Hansen, Department of Chemistry, Technical University of Denmark, Denmark Hainer Wackerbarth, Department of Chemistry, Technical Universi@ of Denmark, Denmark Hans EM Christensen, Department of Chemistry, Technical University of Denmark, Denmark Diffusion controlled and film voltammetry are established techniques to address thermodynamic and interfacial electron transfer of both small redox metalloproteins and multi-centre redox metalloenzymes. Introduction of single-crystal, atomically planar metal electrode surfaces and in situ scanning tunnelling microscopy (STM) directly in aqueous buffer under electrochemical potential control, has, however, added new perspectives to protein bioelectrochemistry. Single-crystal electrodes enhance significantly voltammetric and interfacial capacitance sensitivity, and in situ STM addresseseven single biomolecules in electron transporting action. Other state-of-the-art surface science tools such as microcantilever sensor techniques and X-ray photoelectron spectroscopy have supported this. We overview studies in our group based on single-crystal voltammetry, interfacial capacitance, X-ray photoelectron spectroscopy,microcantilever sensortechniques, and in situ STM of several redox proteins on functionally modified Au( 11l)electrode surfaces. The proteins are: Pseudomonas aeruginosa azurin, Saccharomyces cerevisiae cytochrome c, Pyrococcus furiosis [3Fe-4S] ferredoxin, and the trimeric blue copper oxidase Achromobacter xylosoxidans Cu-nitrite reductase, as shown in Figure I. The data point to new ways of mapping and controlling redox metalloprotein orientation and function at well-characterised electrochemical surfaces. This is important in future electrochemical biosensor design towards the single-molecule level. Zhang, J.; Chi, Q.; Kuznetsov, A.M.; Hansen, A.G.; Wackerbarth, H.; Christensen, H.E.M.; Andersen, J.E.T.; Ulstrup, J. J. Phys. Chem. B 2002,106,1131-1152. Fig. 1 Molecular structures. In the left column the Cu-proteins azurin (top) and the enzyme nitrite reductase (bottom). In the right column the iron containing (yeast) cytochrome c (top) and ferredoxin (bottom)