Gold fibers as a platform for biosensing.

A new form of high surface bioelectrode based on electrospun gold microfiber with -immobilized glucose oxidase was developed. The gold fibers were prepared by electroless deposition of gold nanoparticles on a poly(acrylonitrile)-HAuCl(4) electrospun fiber. The material was characterized using electron microscopy, XRD and BET, as well as cyclic voltammetry and biochemical assay of the immobilized enzyme. The surface area of the gold microfibers was 2.5 m(2)/g. Glucose oxidase was covalently crosslinked to the gold surface using cystamine monolayer and glutardialdehyde, and portrayed characteristic catalytic currents for oxidizing glucose using a ferrocene methanol mediator. Limit of detection of glucose is 0.1 mM. The K(m) of the immobilized enzyme is 10 mM, in accordance with other reports of immobilized glucose oxidase. The microfiber electrode was reproducible and showed correlation between fiber weight, cathodic current and enzymatic loading.