Determination of glucose using bienzyme layered assembly magnetoelastic sensing device

A bienzyme layered assembly on magnetoelastic sensor, consisting of horseradish peroxidase and glucose oxidase is used to sense glucose by the horseradish peroxidase-mediated oxidation of 3,3′,5,5′-tetramethylbenzidine, by H2O2, and the formation of the insoluble product on the sensor surface. A horseradish peroxidase is used to analyze hydrogen peroxide (H2O2) via the biocatalyzed oxidation of tetramethylbenzidine and the precipitation of the insoluble product. The glucose oxidase catalyzed oxidation of glucose produces gluconic acid and H2O2, and the generated H2O2 effects the formation of the insoluble product in the presence of horseradish peroxidase. The insoluble product accumulated on the sensor surface resulting in shifts of the sensor resonance frequency which are correlated with the amount of H2O2 or glucose. The biosensor response is linear in the range of glucose concentrations of 5–50 mM, with a detection limit of 2 mM at a noise level of ∼10 Hz. The biosensor is applied to determine glucose concentration in urine sample.