Biosensor for determination of glucose in real samples of beverages

A biosensor was developed for spectrophotometric determination of glucose concentrations in real samples of orange juice energetic drinks, and sport drinks. The biosensor consisted of glucose oxidase (GOD) and horseradish peroxidase (HRP) immobilized onto polyaniline activated with glutaraldehyde (PANIG). Immobilization parameters were optimized for GOD, and maximum immobilization yield was 16% when 5.0 mg of PANIG and 8.9 U prepared in 0.1 mol.L-1 sodium phosphate buffer (pH 7.0) reacted for 60 minutes at 4 degrees C with gentle stirring. The linear operational range for glucose determination using optimized operational parameters was between 0.05 and 6.0 mg.mL(-1) with a very good reproducibility of response. The results obtained in the biosensor were compared with those obtained using free enzymes (commercial kits) and then validated through statistical analysis using the Tukey test (95% confidence interval).