Department of Chemistry, State University of Maringá, Maringá 87020-900, PR, Brazil.
Department of Chemistry, State University of Londrina, Londrina 86057-970, PR, Brazil.
Molecules. 2022 Dec 6;27(23):8614. doi: 10.3390/molecules27238614.
An electrochemical sensor for simultaneous determination of Benserazide (BEZ) and levodopa (L-dopa) was successfully developed using a glassy carbon electrode (GCE) modified with multi-walled carbon nanotube and nitrogen-doped titanium dioxide nanoparticles (GCE/MWCNT/N-TiO). Cyclic voltammetry and square wave voltammetry were employed to investigate the electrochemical behavior of different working electrodes and analytes. In comparison with unmodified GCE, the modified electrode exhibited better electrocatalytic activity towards BEZ and L-dopa and was efficient in providing a satisfactory separation for oxidation peaks, with a potential difference of 140 mV clearly allows the simultaneous determination of these compounds. Under the optimized conditions, linear ranges of 2.0-20.0 and 2.0-70.0 μmol L were obtained for BEZ and L-dopa, respectively, with a limit of detection of 1.6 µmol L for BEZ and 2.0 µmol L for L-dopa. The method was applied in simultaneous determination of the analytes in pharmaceutical samples, and the accuracy was attested by comparison with HPLC-DAD as the reference method, with a relative error lower than 4.0%.
一种电化学传感器，用于同时测定苯乙嗪（BEZ）和左旋多巴（L-dopa），成功地使用玻碳电极（GCE）修饰多壁碳纳米管和氮掺杂二氧化钛纳米粒子（GCE/MWCNT/N-TiO）开发。循环伏安法和方波伏安法被用来研究不同工作电极和分析物的电化学行为。与未修饰的 GCE 相比，修饰电极对 BEZ 和 L-dopa 表现出更好的电催化活性，并且能够有效地提供令人满意的氧化峰分离，其 140 mV 的电位差明显允许这些化合物的同时测定。在优化条件下，BEZ 和 L-dopa 的线性范围分别为 2.0-20.0 和 2.0-70.0 μmol L，BEZ 的检测限为 1.6 μmol L，L-dopa 的检测限为 2.0 μmol L。该方法被应用于药物样品中分析物的同时测定，并通过与 HPLC-DAD 作为参考方法进行比较来验证准确性，相对误差低于 4.0%。
