Determination of Glucose by Catalytic Fluorimetry with Hemoglobin Mimetic Peroxidase

A spectrofluorimetric method was proposed for determining hydrogen peroxide and glucose based on the fluorescence velocity of the mimetic enzyme, hemoglobin-catalyzed oxidation of L-tyrosine by hydrogen peroxide, which coupled with the oxidation of glucose catalyzed by glucose oxidase. The optimal conditions, the influence of different buffers and concentrations on the relative fluorescence velocity were examined. The results showed that the enhancement effect was obtained in NH3 NH4Cl solution, especially at high pH value. The effect of interferences on the determination of H2O2 was investigated. The reaction product was monitored fluorimetrically, with a 3 sigma detection limit of 1.33 x 10(-8) mol/L glucose. A linear calibration graph was obtained over the glucose concentration range of 0.0 - 1.2 x 10(-4) mol/L. The relative standard derivation at a glucose concentration of 4.0 x 10(-6) mol/L was 3.8% (nD9). The proposed method was successfully applied to the determination of glucose in fruit tissue fluid.