title: Enzyme modification of platinum microelectrodes for detection of cholesterol in vesicle lipid bilayer membranes.
abstract: Platinum microelectrodes are modified with a lipid bilayer membrane incorporating cholesterol oxidase. Details for electrode surface modification are presented along with characterization studies of electrode response to cholesterol solution and to cholesterol contained in the lipid bilayer membrane of vesicles. Ferrocyanide voltammetric experiments are used to track deposition of a submonolayer of a thiol-functionalized lipid on the platinum electrode surface, vesicle fusion for bilayer formation on the thiolipid-modified surface, and incorporation of cholesterol oxidase in the electrode-supported thiolipid/lipid bilayer membrane. The data are consistent with formation of a lipid bilayer structure on the electrode surface that contains defects. Experiments for detection of cholesterol solubilized in cyclodextrin solution show steady-state current responses that correlate with cholesterol concentration. Direct contact between the electrode and a vesicle lipid bilayer membrane shows a response that correlates with vesicle membrane cholesterol content.
authors.affiliation: Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7078, USA.
authors.forename: Anando
authors.initials: A
authors.lastname: Devadoss
authors.forename: M Simona
authors.initials: MS
authors.lastname: Palencsár
authors.forename: Dechen
authors.initials: D
authors.lastname: Jiang
authors.forename: Michael L
authors.initials: ML
authors.lastname: Honkonen
authors.forename: James D
authors.initials: JD
authors.lastname: Burgess
mesh_terms: D002784:Cholesterol / Q000032:analysis* / Q000378:metabolism*; D008051:Lipid Bilayers; D008839:Microelectrodes; D010088:Oxidoreductases / Q000378:metabolism*; D010984:Platinum / Q000737:chemistry*; D013025:Glycine max
chemical_list: D008051:Lipid Bilayers; D010984:Platinum; D002784:Cholesterol; D010088:Oxidoreductases