Polymyxin-Coated Au and Carbon Nanotube Electrodes for Stable [NiFe]-Hydrogenase Film Voltammetry

• DOI: 10.1021/la703984z
• Publication Date: 2008-05-07T10:01:03Z
• Authors: Freek J. M. Hoeben; Iddo Heller; Simon P. J. Albracht; Cees Dekker; Serge G. Lemay; Hendrik A. Heering
• Keywords: Bioelectrochemistry; Hydrogenase; Carbon fibers

We report on the use of polymyxin (PM), a cyclic cationic lipodecapeptide, as an electrode modifier for studying protein film voltammetry (PFV) Au and single-walled carbon nanotube (SWNT) electrodes. Pretreating electrodes with PM allows subsequent immobilization active submonolayer [NiFe]-hydrogenase from Allochromatium vinosum (Av H2ase). Probed by (CV), adsorbed enzyme exhibits characteristic electrocatalytic behavior that is stable several hours under continuous potential cycling. An unexpected feature procedure presence chloride ions prerequisite obtaining activity. Atomic force microscopy (AFM) relates observed catalytic activity to enzymatic adsorption at PM/Au(111) surface, combination concentration-dependent CV AFM used investigate interaction between layer.