Electrochemical sensing platform for anticonvulsant drug carbamazepine detection based on graphitic carbon nitride and tetrabutylammonium chloride ionic liquid

The development of a rapid and straightforward electrochemical approach for the quantification of the anticonvulsant drug carbamazepine (CBZ) is herein presented. Carbon paste electrode (CPE) was bulk modified with a type of two-dimensional conjugated polymer, i.e., graphitic carbon nitride (g-C3N4), and additionally with an ionic liquid tetrabutylammonium chloride (TBACl) to obtain advanced electrochemical sensor for CBZ. Synthesized g-C3N4 material was structurally and morphologically characterized by Raman spectroscopic, FTIR, and SEM/EDX methods. CV experiments showed that the resulting electrode (TBACl-g-C3N4-CPE) has an improved electrochemical response compared to unmodified CPE and g-C3N4-CPE due to the synergistic effect of electrode modifiers, as well as that the CBZ oxidation process is irreversible and diffusion-controlled. After optimization steps concerning the amount of electrode modifiers and the selection of pH of the supporting electrolyte, the analytical performance of TBACl-g-C3N4-CPE was investigated by direct anodic square-wave voltammetry (SWV). The most intensive peak of the target analyte was obtained in Britton-Robinson buffer solution at pH 7.0, whereby the developed SWV method was characterized by a linear concentration range of CBZ from 0.42 to 9.31 mu moL L- 1, limit of detection (LOD) of 0.13 mu moL L- 1, and relative standard deviation lower than 3 %. The interference study showed that TBACl-g-C3N4-CPE exhibits adequate selectivity for CBZ in the presence of ions/ compounds commonly present in the urine matrix. The developed sensor was utilized to determine CBZ in pharmaceuticals and spiked human urine sample with excellent recovery and reproducibility, indicating a good application capability of TBACl-g-C3N4-CPE for monitoring CBZ in different matrices.