Differential Pulse Voltammetric (DPV) Determination of the Local Anesthetic Bupivacaine using Polyimide Membrane-Based Electrodes

Abstract

Aromatic selective polyimide (PI) membrane based voltammetric electrodes were prepared for bupivacaine measurements. Polyimide membranes were synthesized from 4,4′-diaminobenzanilide (DABA) and different aromatic dianhydrides (pyromellitic dianhydride (PMDA), benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BPDA), 4,4′-oxydiphthalic anhydride (ODPA)) through two-step polycondenzation reactions. The structural properties of the obtained benzanilide based PIs were characterized by various analytical techniques. For the preparation of voltammetric electrodes, these polyimide films were coated with polyimide solution by drop-casting on the surface of a platinum working electrode. Due to the excellent film properties and suitable porosity, the prepared benzanilide based polyimide films were used as the membrane for selective determination of bupivacaine in the presence of interferents that included lactose, glucose and sucrose. For this reason, the selectivity of the modified electrode to bupivacaine obtained from the prepared PI film toward the potential interferences was investigated by differential pulse voltammetry (DPV). The results of voltammetric study showed that polyimide films responded to only bupivacaine at a potential of approximately +0.92 V. The polyimide membrane modified electrode showed a rapid response time, a high R-value of 0.9941, high reproducibility and good selectivity for bupivacaine. The limit of detection (LOD) and the limit of quantitation (LOQ) were determined to be 16.82 µM and 50.46 µM, respectively. Thus, benzanilide based polyimides may be successfully used as selective membranes for preparation of bupivacaine sensors. This structure may be a precursor for the preparation of simultaneous or needle-shaped sensors in the future.