The evaluation of the efficacy of drugs’ action is of crucial importance for preventing adverse effects due to over- or under-dosing. This is especially valuable in the case of propofol, a benchmark anesthetic, since its plasma concentration has to be continuously monitored to achieve and maintain a certain level of sedation during the surgery. To this end, long-term monitoring approaches have to be implemented. Electrochemical sensors have taken great interest for propofol monitoring. However, the problem of fouling of the propofol on the sensing electrodes, as due to compound-polymerization caused by successive measurements, makes almost impossible the long-term drug monitoring of such a compound. For the first time by this study, we have shown that long-term monitoring of propofol can be achieved by electrochemical sensors based on Pencil Graphite Electrode (PGE) with a proper clay/graphite ratio. Our research has shown that a clay/graphite ratio of 0.4 prevents fouling and hence enables monitoring of propofol.up to 4-hours. Surface analysis of various PGEs has been conducted via Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS) whereas detection of propofol has been investigated by Cyclic Voltammetry (CV).

中文翻译：

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丙泊酚和铅笔石墨电极结垢效应的长期监测

评估药物作用的功效对于预防因过量或不足剂量引起的不良反应至关重要。这对于作为基准麻醉剂的丙泊酚特别有价值，因为必须持续监测其血浆浓度以在手术过程中达到并保持一定的镇静水平。为此，必须实施长期监测方法。电化学传感器对丙泊酚监测产生了极大的兴趣。然而，由于连续测量引起的化合物聚合，传感电极上的丙泊酚污染问题几乎不可能对这种化合物进行长期药物监测。首次通过这项研究，我们已经证明，丙泊酚的长期监测可以通过基于铅笔石墨电极 (PGE) 的电化学传感器实现，具有适当的粘土/石墨比例。我们的研究表明，粘土/石墨比率为 0.4 可防止结垢，因此可对丙泊酚进行长达 4 小时的监测。已经通过扫描电子显微镜 (SEM) 和电化学阻抗谱 (EIS) 对各种 PGE 进行了表面分析，而通过循环伏安法 (CV) 研究了丙泊酚的检测。