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.