title: Kinetic studies of glucose oxidase in polyelectrolyte multilayer films by means of scanning electrochemical microscopy (SECM).
abstract: Multilayer films of glucose oxidase (GOx) and poly(dimethyl diallyl ammonium chloride) (PDDA) prepared by layer-by-layer deposition were studied using scanning electrochemical microscopy (SECM). Aminated glass slides were coated with five bilayers of poly(styrene sulfonate) (PSS) and PDDA and used as substrates onto which GOx/PDDA multilayers were deposited. UV-Vis experiments confirmed multilayer growth, scanning force microscopic images provided morphological information about the films. SECM current-distance curves enabled the determination of kinetic information about GOx in GOx/PDDA multilayers as a function of layer number, film termination, inert covering layers, and enzyme substrate concentration after fitting to numerical models. The results indicate that only the topmost layers contributed significantly to the conversion. An odd-even pattern was observed for PDDA-terminated films or GOx-terminated films that correlated with morphological changes.
authors.affiliation: Carl von Ossietzky University of Oldenburg, Faculty of Mathematics and Science, Center of Interface Science, Department of Pure and Applied Chemistry and Institute for Chemistry and Biology of the Marine Environment, D-26111 Oldenburg, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Burchardt
authors.forename: Gunther
authors.initials: G
authors.lastname: Wittstock
mesh_terms: D004573:Electrolytes / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D005949:Glucose Oxidase / Q000378:metabolism* / Q000648:ultrastructure*; D007700:Kinetics; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D004573:Electrolytes; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D005949:Glucose Oxidase; D005947:Glucose