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

Biosensors containing recombinant carbohydrate oxidase from Microdochium ni vale (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 biosens ors showed a linear calibration graph up to 0.018 mol dm(-3) of glucose whe n operated at 0.04-0.36 V vs. SCE. Almost no change was detected in the sen sitivity of the biosensors at pH 7.2-8.1. The biosensors responded to a ran ge of D-aldoses, but maximal sensitivity of the biosensor was with D-glucos e. The biosensors gave no response to polyhydroxylic compounds such as D-ma nnitol, D-sorbitol and inositol. The advantage of the biosensor in comparis on to the biosensor based on Aspergillus niger glucose oxidase is a wide li near range, low sensitivity to oxygen and (in some cases) broad specificity .