Hassan Saad S M, Kamel Ayman H, Fathy Mahmoud Abdelwahab
Department of Chemistry, Faculty of Science, Ain Shams University, Abbasia, Cairo 11566, Egypt.
Department of Chemistry, Faculty of Science, Ain Shams University, Abbasia, Cairo 11566, Egypt; Department of Chemistry, College of Science, Sokheer, 32038, Bahrain.
Talanta. 2023 Feb 1;253:123907. doi: 10.1016/j.talanta.2022.123907. Epub 2022 Sep 7.
A cost-effective, highly selective and sensitive paper-based potentiometric combined sensor for losartan potassium drug (LOS) is fabricated, characterized and used for the drug monitoring. The sensor consists of 2 strips of filter paper (20 × 5 mm each) as platform, each imprinted with 4 mm diameter circular spot of carbon. One carbon spot is covered by a reduced graphene oxide (rGO) for use as a substrate for the recognition sensor and the other without rGO is used for the reference electrode. LOS molecularly imprinted drug polymer (MIP) is applied onto the graphene oxide containing strip to act as a drug recognition sensing material and a solid-state polyvinyl butyral (PVB) is applied onto the second carbon spot to act as a reference electrode. Performance characteristics of the combined sensor are examined with chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). Increase effect of rGO on the interfacial double-layer capacitance of the sensing membrane and consequently on the potential stability is confirmed. The developed combined sensor (strip cell) displays a Nernstian slope of -58.2 ± 0.3 mV/decade (R = 0.9994) over the linear range 8.5 × 10 - 6.9 × 10 M with a detection limit of 2.7 ± 0.3 × 10 M. The sensor shows remarkable selectivity toward various related compounds especially those commonly used by the COVID-19 patients such as paracetamol, ascorbic acid and dextromethorphan. The assay method is validated and proved to be satisfactory for direct potentiometric determination of LOS-K in some pharmaceutical formulations and in spiked human urine samples. An average recovery of 96.3 ± 0.3-98.7 ± 0.6% of the nominal or spiked concentration and a mean relative standard deviation of ±0.6% are obtained. The use of an indicating and a reference electrodes combined into a single flexible disposable paper platform enables applications to a minimum sample volume due to the close proximity of the responsive membrane and the liquid junction. The efficiency of the proposed sensor in complex urine matrix suggests its application in hospitals for rapid diagnosis of overdose patients and for quality control/quality assurance tests in pharmaceutical industry.
制备、表征了一种用于监测氯沙坦钾药物（LOS）的具有成本效益、高选择性和高灵敏度的纸质电位复合传感器，并将其用于药物监测。该传感器由两条滤纸（每条20×5毫米）作为平台组成，每条滤纸印有直径4毫米的圆形碳点。一个碳点覆盖有还原氧化石墨烯（rGO），用作识别传感器的基底，另一个没有rGO的碳点用作参比电极。将LOS分子印迹药物聚合物（MIP）应用于含氧化石墨烯的纸条上，作为药物识别传感材料，将固态聚乙烯醇缩丁醛（PVB）应用于第二个碳点上，作为参比电极。采用计时电位法（CP）和电化学阻抗谱（EIS）对复合传感器的性能特征进行了研究。证实了rGO对传感膜界面双层电容的增加作用，进而对电位稳定性的增加作用。所开发的复合传感器（条形电池）在8.5×10 - 6.9×10 M的线性范围内显示出-58.2±0.3 mV/decade的能斯特斜率（R = 0.9994），检测限为2.7±0.3×10 M。该传感器对各种相关化合物表现出显著的选择性，尤其是对COVID-19患者常用的那些化合物，如对乙酰氨基酚、抗坏血酸和右美沙芬。该测定方法经过验证，被证明可用于直接电位法测定某些药物制剂和加标人尿样中的LOS-K。获得了名义浓度或加标浓度的平均回收率为96.3±0.3 - 98.7±0.6%，平均相对标准偏差为±0.6%。由于响应膜和液接界距离很近，将指示电极和参比电极组合在一个柔性一次性纸质平台上，使得能够应用于最小的样品体积。所提出的传感器在复杂尿液基质中的效率表明其可应用于医院对过量用药患者进行快速诊断以及制药行业的质量控制/质量保证测试。
