title: Surface-bound lipid vesicles encapsulating redox species for amperometric biosensing of pore-forming bacterial toxins.
abstract: A new method is described to signal the presence of a staphylococcal toxin (streptolysin, SLO) by a membrane-based biosensor fabricated with bilayer vesicles of phosphatidylcholine lipids and cholesterol on a gold electrode. The controlled release of encapsulated redox species from the surface-bound vesicles is mediated by the pore-formation functionality of SLO, allowing amperometric detection of the targeted toxin. Effects of BSA and Triton-100 on membrane permeability and redox release have been assessed, and a thin layer electrolysis mechanism has been proposed to account for the observed voltammetric behavior. The method is applicable to the detection of functionally similar protein toxins.
authors.affiliation: Department of Chemistry, University of California, Riverside, California 92521, USA.
authors.forename: Danke
authors.initials: D
authors.lastname: Xu
authors.forename: Quan
authors.initials: Q
authors.lastname: Cheng
mesh_terms: D001426:Bacterial Proteins; D015374:Biosensing Techniques / Q000379:methods*; D002463:Cell Membrane Permeability; D004563:Electrochemistry / Q000379:methods; D006046:Gold / Q000737:chemistry; D008051:Lipid Bilayers / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D013301:Streptolysins / Q000032:analysis / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D008051:Lipid Bilayers; D013301:Streptolysins; C025964:streptolysin O; D006046:Gold