Tailoring Electrochemical Activity of Acemetacin with Electrocatalytic Properties of Graphene Derivatives

In this study, differential pulse (DPV) and cyclic voltammetry (CV) were used to investigate the electrocatalytic effects of two oxygen-containing graphene derivatives, as surface modifiers, on the oxidation mechanism of acemetacin, a non-steroidal anti-inflammatory drug. Scanning electron microscopy was employed to examine the modified glassy carbon electrodes surface, and it was discovered, that the morphology and composition of the coatings strongly influenced the electroanalysis of ACM. Cyclic voltammetry was used to confirm the ACM adsorption dependence on the type and structure of modifier. Density functional theory (DFT) calculations were performed to analyse the electron density and spatial distribution of the HOMO orbital of ACM in order to determine the most probable oxidation site in the molecule. It was found that the composition and structure of the modifiers influenced the surface properties of the working electrodes and thus strongly affected ACM adsorption. Finally, it was observed that different oxidation mechanisms were preferred at each of the modifier layer. To determine the relationship between ACM oxidation mechanism and analytical usability of developed sensors, under optimized conditions, for both working electrodes calibration curves were developed, and the methods were applied to determine ACM in real samples. The performed studies confirm the need for rational design of used graphene-derivative materials as electrode surface modifiers.