Comparison of tyrosinase biosensor based on carbon nanotubes with DPPH spectrophotometric assay in determination of TEAC in selected Moravian wines

摘要

An amperometric biosensor based on carbon paste electrode coated with a thin layer of carbon nanotubes and Nafion film containing the tyrosinase enzyme was used for direct determination of Trolox equivalent antioxidant capacity (TEAC) in selected Moravian wines. The results were compared with an official spectrophotometric method using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). Although based on the different principles, results of both the methods were comparable; correlation coefficient 0.9752 was found. TEAC values differ from ca. 50 to ca. 280 mg dm(-3) being increased from white wines to red varieties. Optimum conditions for the biosensor application were investigated.