In this work, we aim to develop a highly sensitive sensor for the electroanalytical determination of the theophylline (THP). We have developed a new sensor by packing the matrix of cholesterol (CHE), graphene oxide (GO) loaded carbon paste in a polytetrafluoroethylene (PTFE) tube, and used for investigation. Our study shows that as compared to the carbon paste electrode (CPE) the modified sensor was sensitive with a detection limit of 4.45 nM. The adsorption controlled mechanism of the THP in the sensor process was involved with two numbers of electrons and protons. Effect of pH study shows the highest peak current at pH 6.0. Other physicochemical factors were calculated by studying the scan rate effect. The interference of excipients and metal ions with THP was investigated to check the sensitivity and selectivity of the modified sensor. To check the efficiency and real-time application, we applied this sensor in the analysis of THP in the tablet sample and discovered that, the new fabricated sensor has significant detection capacity with good recovery.

在这项工作中，我们的目标是开发一种用于茶碱 (THP) 电分析测定的高灵敏度传感器。我们通过在聚四氟乙烯 (PTFE) 管中填充胆固醇 (CHE)、氧化石墨烯 (GO) 加载的碳糊的基质开发了一种新传感器，并用于研究。我们的研究表明，与碳糊电极 (CPE) 相比，改进后的传感器灵敏，检测限为 4.45 nM。THP在传感器过程中的吸附控制机制涉及两个电子和质子。pH 研究的影响显示在 pH 6.0 时最高峰值电流。通过研究扫描速率效应计算其他理化因素。研究了赋形剂和金属离子对 THP 的干扰，以检查改进传感器的灵敏度和选择性。