Herein, a simple, rapid, cost-effective and sensitive poly(thionine)-based electrochemical sensor is described to determine trace amounts of tetracycline. In the present work, electropolymerization of thionine was performed to create a stable film on the surface of carbon nanotube paste electrode. The modified electrode surface was investigated by scanning electron microscopy (SEM) and its complete formation was confirmed. Moreover, the unmodified and modified electrodes were then studied by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) technique. The linear sweep voltammetry (LSV) technique was used for the quantification of tetracycline 0.1 M phosphate buffer solution (PBS) at pH 6.0 by the modified electrode as a poly(thionine)/carbon nanotube/carbon paste electrode (PTH/CNT/CPE). Also, the effects of different experimental parameters including type of the supporting electrolyte, pH value, and scan rate were evaluated. The proposed sensor indicated a linear range of 0.50–20.0 µM, a limit of quantification and detection of 0.05 µM and 0.13 µM, respectively, under the optimized conditions. Low relative standard deviation values confirmed that the repeatability and reproducibility of the modified electrodes are acceptable in preparation and determination fully procedures. Finally, the proposed method was successfully applied for tetracycline determination in urine and 250 mg TC tablet with satisfactory results.

中文翻译：

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作为稳定膜的硫氨酸与碳纳米管的电聚合，用于灵敏检测四环素抗生素药物

本文中，描述了一种简单，快速，具有成本效益且灵敏的基于聚（硫氨酸）的电化学传感器，用于测定痕量的四环素。在本工作中，进行了硫氨酸的电聚合以在碳纳米管糊状电极的表面上形成稳定的膜。通过扫描电子显微镜（SEM）研究修饰的电极表面，并确认其完整形成。此外，然后通过电化学阻抗谱（EIS）和循环伏安法（CV）技术研究了未修饰和修饰电极。使用线性扫描伏安法（LSV）技术通过修饰电极作为聚（硫氨酸）/碳纳米管/碳糊电极（PTH / CNT / CPE）定量定量pH为6.0的四环素0.1 M磷酸盐缓冲溶液（PBS） 。也，评估了不同实验参数（包括支持电解质的类型，pH值和扫描速率）的影响。建议的传感器在优化条件下的线性范围为0.50–20.0 µM，定量和检出限分别为0.05 µM和0.13 µM。低的相对标准偏差值证实，修饰电极的重复性和再现性在制备和完全测定过程中是可以接受的。最终，该方法成功应用于尿液和250 mg TC片中四环素的测定，结果令人满意。在优化条件下分别为13 µM。低的相对标准偏差值证实，修饰电极的重复性和再现性在制备和完全测定过程中是可以接受的。最终，该方法成功应用于尿液和250 mg TC片中四环素的测定，结果令人满意。在优化条件下分别为13 µM。低的相对标准偏差值证实，修饰电极的重复性和再现性在制备和完全测定过程中是可以接受的。最终，该方法成功应用于尿液和250 mg TC片中四环素的测定，结果令人满意。