ChemistrySelect, cilt.8, sa.14, 2023 (SCI-Expanded)
For the first time, a boron-doped diamond electrode was utilized to quantitatively determine flavonoid fisetin (FST). Cyclic voltammetric studies have shown that the electrochemical oxidation of FST is irreversible and well-separated two peaks (PA1 and PA2) in 0.1 M HNO3 solution. The effects of electrode pretreatment, solution pH, nature of the supporting electrolyte, and instrumental variables on the peak current and potentials of the FST were investigated by square-wave voltammetry (SWV) and then optimum ones were determined. It was observed that the cathodically pre-treated BDD (CPT-BDD) electrode‘s performance was better than the other pre-treatment procedures for increasing the FST oxidation signal. Under optimized conditions and using the SWV technique, the response of the first anodic peak (PA1) of the FST was proportional in a concentration range of 0.5–20.0 μg mL−1 (1.7×10−6–6.9×10−5 mol L−1) with a detection limit of 0.08 μg mL−1 (2.8×10−7 mol L−1). Also, it was successfully demonstrated that the proposed method is applicable in commercial nutritional supplement formulations.