Study on a Pyruvate Oxidase Biosensor Based on β-Cyclodextrin with Ferrocene as Electron-Transfer Mediator

Abstract A pyruvic acid biosensor was constructed by the use of ferrocene, which was included in the β-cyclodextrin as electron-transfer mediator, as well as glutaraldehyde cross-linked membrane of egg white and β-cyclodextrin as matrix of enzyme immobilization. Because of the excellent electron-transfer efficiency of ferrocene, the microenvironment from β-cyclodextrin, and also the inclusion complexation between them, the biosensor has quite good properties. The linear detection limiting of this biosensor decreased to 5.68 × 10−7 mol/L with excellent stability for 2.58% of relative standard deviation (RSD) during six individual detections.