Aishwarya K G, Nayaka Y Arthoba, Pradeepa E, Sahana H R
Department of Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta, 577451, Karnataka, India.
Department of Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta, 577451, Karnataka, India.
Anal Biochem. 2025 Mar;698:115733. doi: 10.1016/j.ab.2024.115733. Epub 2024 Dec 3.
In the present work, a convenient, efficient and disposable electrochemical sensor has been developed by electropolymerizing methylene blue (PMB) on the surface of a pencil graphite electrode (PGE), which facilitates the electrochemical analysis of an antioxidant l-Ascorbic Acid (AA). The structural characteristics of both the methylene blue modified pencil graphite electrode (PMB/PGE) and the bare pencil graphite electrode (BPGE) have been examined using scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray analysis (EDX). Additionally, the charge transfer behavior has been evaluated using the electron impedance spectroscopy (EIS). The voltammetric response of AA has been examined using different methods, such as differential pulse voltammetry (DPV) and linear sweep voltammetry (LSV). This exploration has been carried out in 0.1 M phosphate buffer solution (PBS) of physiological pH 7.0. The electrochemical sensor PMB/PGE proposed in this study exhibited an improved peak current and a slight negative shift in peak potential for AA compared to bare electrode. The enhancement in peak current at the modified electrode has been attributed to the electrocatalytic characteristics of the modifiers. The limit of detection (LOD) for AA has been determined using the differential pulse voltammetry (DPV), with concentrations ranging from 1.0 μM to 12.0 μM. The calculated LOD value has been found to be 0.15 μM. The selectivity and practicality of the modified electrode has been assessed through the real sample analysis and demonstrating its capability to detect AA in the presence of paracetamol (PA) resulting in satisfactory recovery results. Hence the proposed sensor could be successfully validated for the determination of AA in pharmaceutical sample.
在本工作中，通过在铅笔石墨电极（PGE）表面电聚合亚甲基蓝（PMB），开发了一种便捷、高效且一次性使用的电化学传感器，这有助于对抗氧化剂l-抗坏血酸（AA）进行电化学分析。已使用扫描电子显微镜（SEM）结合能量色散X射线分析（EDX）研究了亚甲基蓝修饰铅笔石墨电极（PMB/PGE）和裸铅笔石墨电极（BPGE）的结构特征。此外，已使用电子阻抗谱（EIS）评估了电荷转移行为。已使用不同方法，如差分脉冲伏安法（DPV）和线性扫描伏安法（LSV），研究了AA的伏安响应。该研究是在生理pH值为7.0的0.1 M磷酸盐缓冲溶液（PBS）中进行的。与裸电极相比，本研究中提出的电化学传感器PMB/PGE对AA表现出更高的峰值电流和峰值电位的轻微负移。修饰电极上峰值电流的增强归因于修饰剂的电催化特性。使用差分脉冲伏安法（DPV）测定了AA的检测限（LOD），浓度范围为1.0 μM至12.0 μM。计算得出的LOD值为0.15 μM。通过实际样品分析评估了修饰电极的选择性和实用性，并证明了其在对乙酰氨基酚（PA）存在下检测AA的能力，获得了令人满意的回收率结果。因此，所提出的传感器可成功用于药物样品中AA的测定。
