Electropolymerized Eugenol-MWNT-Based Electrode for Voltammetric Evaluation of Wine Antioxidant Capacity

Eugenol electropolymerization conditions on multiwalled carbon nanotube based glassy carbon electrode (MWNT/GCE) have been found. The polyeugenol/MWNT/GCE shows reversible redox steps of o-quinone fragment in acidic media. Natural phenolic antioxidants are oxidized on polyeugenol/MWNT/GCE at 0.52V excluding resveratrol (0.62V). Differential pulse voltammetry on polyeugenol/MWNT/GCE was applied for the evaluation of wine antioxidant capacity (AOC). The AOC was expressed in catechin equivalents per 1L of wine. The linear dynamic range is 1.00-250 mu M with LOD and LOQ of 0.21 and 0.71 mu M of catechin, respectively. Positive correlations for AOC with antioxidant activity (r=0.9840) and total phenolics content (r=0.9944) were observed.