Sensitive Electrochemical Determination of Hyperin Based on Electrochemically Activated ZrO2 Nanoparticles-Modified Carbon Paste Electrode

A novel electrochemically activated ZrO 2 nanoparticles modified carbon paste electrode (CPE) (ZrO 2 -CPE(ox)) was prepared and applied for selective and sensitive determination of hyperin. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and electrochemical experiment were used to characterize the ZrO 2 nanoparticles and investigate the electrochemical performance of the ZrO 2 -CPE(ox). Compared with bare CPE and electrochemically activated CPE (CPE(ox)), the ZrO 2 -CPE(ox) got more reactive sites by electrochemical treatment and exhibited larger effective surface area and more excellent electrochemical catalytic activity toward the redox of hyperin. Under the optimum conditions, the oxidation peak currents showed a linear relationship with the concentrations of hyperin in the range of 5 . 0 × 1 0 − 9 – 2 . 0 × 1 0 − 6 mol L − 1 and 2 . 0 × 1 0 − 6 – 1 . 2 × 1 0 − 5 mol L − 1 , and a low detection limit of 1 . 0 × 1 0 − 9 mol L − 1 was achieved for hyperin. Moreover, the proposed method exhibited an excellent selectivity, stability, reproducibility and repeatability, which make it very suitable for a potential choice for determining the concentrations of hyperin in drug matrices.