MWCNTs-supported Ni electrocatalyst-modified CPE as a sensing platform for voltammetric determination of ibuprofen in pharmaceutical formulations

In this work, a sensitive and reproducible voltammetric methodology using a modified carbon paste electrode has been established for the determination of the non-steroidal anti-inflammatory drug ibuprofen. MWCNTs-supported Ni electrocatalyst was applied as a bulk carbon paste modifier to fabricate the Ni-MWCNTs-CPE sensor, while square-wave voltammetry was utilized as an electroanalytical technique. Besides, cyclic voltammetry was used to study the electrochemical behavior of ibuprofen on the proposed sensor. Parameters of square-wave voltammetry were optimized using acetate buffer pH 4.5 as an optimal electrolyte. In addition, the sensitivity of the modified carbon paste electrode, as a sensing element, was compared to the unmodified one. Under optimized conditions, a wide linear range was obtained with LOD and LOQ values of 0.86 and 2.61 µM, and 0.13 and 0.39 µM, for bare CPE and Ni-MWCNTs-CPE, respectively. The presence of the modifier in the paste improved the sensitivity of the carbon paste electrode by almost 7 times. In addition, the newly fabricated Ni-MWCNTs-CPE sensor showed better results in terms of precision (RSD up to 2.49%). Finally, the validated voltammetric methodology was successfully applied for the determination of ibuprofen content in pharmaceutical formulations, without any complicated preliminary preparation steps, with recovery values between 94.4 and 98.1%. Graphical abstract