Uncured Polydimethylsiloxane as Binder Agent for Carbon Paste Electrodes: Application to the Quantification of Propranolol

This study describes the use of uncured polydimethylsiloxane (PDMS) as a binder agent to prepare carbon paste electrodes (CPEs). A comparative study between the properties of CPEs prepared with PDMS and mineral oil Nujol®, the most common binder agent for CPEs, was carried out. Cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry showed that PDMS-CPEs presented higher electrical conductivity, active electrochemical area, and wider useful potential window compared with Nujol®-CPEs. Moreover, PDMS-CPEs were more stable in aqueous mixtures containing 50% (v/v) of ethanol or methanol than Nujol®-CPEs. PDMS-CPEs have also provided higher sensitivity and lower limit of detection to propranolol than Nujol®-CPE. Therefore, this study demonstrated that PDMS is a promising alternative binder agent able to produce CPEs with superior chemical/electrochemical stability and improved analytical performance.

本研究阐述了以未固化聚二甲基硅氧烷（PDMS）作为黏合剂制备碳糊电极（CPEs）的方法。本研究对比了以PDMS与碳糊电极最常用黏合剂矿物油Nujol®制备的CPEs的性能差异。通过循环伏安法、电化学阻抗谱及计时电流法表征发现，相较于Nujol®修饰的CPEs（Nujol®-CPEs），PDMS修饰的CPEs（PDMS-CPEs）具备更高的导电率、更大的电化学活性面积以及更宽的可用电位窗口。此外，在体积占比50%的乙醇/甲醇水溶液体系中，PDMS-CPEs的稳定性优于Nujol®-CPEs。相较于Nujol®-CPE，PDMS-CPE对普萘洛尔还展现出更高的灵敏度与更低的检出限。综上，本研究证实PDMS是一种极具应用前景的黏合剂替代品，可用于制备化学/电化学稳定性更优异、分析性能更出色的碳糊电极。