Voltammetric determination of arbutin using carbon paste electrode modified with low crystalline home-prepared rutile TiO₂ nanoparticles

Carbon paste electrodes (CPE) were modified with commercial (Degussa P25, BDH, Merck, Hombikat) and homeprepared rutile TiO2 (HPRT) nanoparticles for the electrochemical determination of arbutin (AR) by differential pulse voltammetry technique. The optimization experiments were performed in Britton-Robinson buffer at pH 2-7 using modified CPEs. 15%-HPRT(25 degrees C)/CPE and 15%-HPRT(400 degrees C)/CPE showed the highest current values among all electrodes at optimum pH, accumulation potential, and duration time values (pH 2, 0.70V and 45 s); consequently, the electrodes were characterized by SEM-EDX, while TiO2 samples by BET and XRD techniques. Electrochemical surface areas of the electrodes were also determined. HPRT(25 degrees C) and HPRT (400 degrees C) samples have the lowest crystallinity which is the reason for their high performance. The linear working range of 15%-HPRT(25 degrees C)/CPE and 15%-HPRT(400 degrees C)/CPE electrodes was 0.5-120 mu M. The detection limit for these electrodes was 32 and 40 nM, and the quantification limit was 107 and 135 nM, respectively. Interference studies, repeatability, reproducibility and the stability of the electrodes were examined, and a reaction mechanism for AR oxidation was proposed and promising results were obtained. The AR determination in a real sample, in the anti-blemish skin serum, was also performed successfully.