A novel electrochemical sensor for metoprolol analysis based on glutardialdehyde–zinc oxide modified boron doped diamond electrode

In this study, glutardialdehyde–zinc oxide modified boron doped diamond electrode (GA2–ZnO/BDDE) was developed as a new electrochemical sensor for the rapid, sensitive and selective determination of metoprolol (MTP). By using boron doped diamond electrode (BDDE), glutardialdehyde modified boron doped diamond electrode (GA2/BDDE) and glutardialdehyde–zinc oxide modified boron doped diamond electrode (GA2–ZnO/BDDE) separately, the electrochemical behavior of MTP on the surfaces of these electrodes was determined by applying cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. According to the results, the linear working range was 9.99 × 10−7–3.85 × 10−5 mol·L−1 and the limit of detection (LOD) was 7.53 × 10−8 mol·L−1 in pH 7 Britton–Robinson buffer solution. In addition, intraday reproducibility of peak current and peak potential were measured on the GA2–ZnO/BDDE surface and the results were calculated as 0.56 and 1 (RSD%), respectively. In order to investigate the reproducibility of GA2–ZnO/BDDE, 5 different modified electrodes were prepared with the same composition and conditions. The interday repeatability of the modified electrode was calculated as 3.13 (RSD%) and 1.05 (RSD%) for interday peak current and peak potential, respectively. The applicability of this method was confirmed by analysis of commercial drug tablets containing MTP as active ingredient. The mean recovery of the developed sensor was 95.6 % ± 1.7.