title: Tetracyanoquinodimethane mediated glucose sensor based on a self-assembling alkanethiol/phospholipid bilayer.
abstract: An amperometric tetracyanoquinodimethane (TCNQ) mediated biosensor for glucose is described, based on a self-assembling alkanethiol/phospholipid bilayer laid down onto a gold surface. Gold was sputter deposited onto chromium coated silicon wafers to a thickness of 200 nm. A monolayer of alkanethiol was allowed to self-assemble from an ethanolic solution of dodecanethiol onto a freshly cleaned gold electrode in an overnight incubation. The monolayer was characterized by ellipsometric, impedance and cyclic voltammetry measurements (capacitance = 1.60 +/- 0.06 microF/cm2, and thickness 1.34 +/- 0.15 nm). A mixture of phospholipid liposomes containing free amino groups was placed on the monolayer and allowed to incubate overnight. The self-assembly of a phospholipid monolayer and allowed to incubate overnight. The onto the alkanethiol monolayer, resulted in the formation of a bilayer. The formation of bilayer was again characterized by impedance and cyclic voltammetry measurements (capacitance = 0.98 +/- 0.09 microF/cm2, and thickness = 1.85 +/- 0.22 nm). TCNQ has been incorporated into the liposomes before the formation of the bilayer. Glucose oxidase was cross-linked with the amino-groups of the phospholipids using bis [2-(sulphosuccinimiidooxicarbonyloxy) ethyl] sulphone. TCNQ which was incorporated in the bilayer acted as an efficient mediator to regenerate glucose oxidase. Cyclic voltammetry of the modified electrode and a response curve for the glucose sensor are reported.
authors.affiliation: Biotechnology Division, National Institute of Standard & Technology, Gaithersburg, MD 20899, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Pandey
authors.forename: R W
authors.initials: RW
authors.lastname: Ashton
authors.forename: H H
authors.initials: HH
authors.lastname: Weetall
authors.forename: R W
authors.initials: RW
authors.lastname: Aston
mesh_terms: D015374:Biosensing Techniques; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D008051:Lipid Bilayers; D009570:Nitriles; D010743:Phospholipids; D013439:Sulfhydryl Reagents
chemical_list: D008051:Lipid Bilayers; D009570:Nitriles; D010743:Phospholipids; D013439:Sulfhydryl Reagents; C013703:tetracyanoquinodimethane; D005949:Glucose Oxidase; D005947:Glucose