The development of an improved glucose biosensor using recombinant carbohydrate oxidase from Microdochium nivale

Abstract

Biosensors containing recombinant carbohydrate oxidase from Microdochium nivale (rMnO) were developed using either a chemically modified carbon paste or a graphite electrode. 1-(N,N-dimethylamine)-4-(4-morpholine)benzene (AMB) and 1,1′-dimethylferrocene (DMFc) were used as the mediators. The biosensors showed a linear calibration graph up to 0.018 mol dm⁻³ of glucose when operated at 0.04–0.36 V vs. SCE. Almost no change was detected in the sensitivity of the biosensors at pH 7.2–8.1. The biosensors responded to a range of D-aldoses, but maximal sensitivity of the biosensor was with D-glucose. The biosensors gave no response to polyhydroxylic compounds such as D-mannitol, D-sorbitol and inositol. The advantage of the biosensor in comparison to the biosensor based on Aspergillus niger glucose oxidase is a wide linear range, low sensitivity to oxygen and (in some cases) broad specificity.