Electro-oxidation and determination of nimesulide at nanosilica modified sensor

Abstract

A novel sensor prepared by mixing nanosilica and graphite powder in an appropriate ratio for the determination of nimesulide drug to study its electrochemical response. Nanosilica showed good conductivity in the transfer of the electrons involved in the oxidation process. The homogeneous mixing of graphite powder with nanosilica has a good response time, stability, sensitivity, and reproducibility. A remarkable increase in the oxidation peak current was observed in phosphate buffer solution (PBS). Effect of accumulation time, scan rate, pH, concentration, excipients, and metal ions on the voltammetric behavior of the drug was studied by various voltammetric techniques. The catalytic properties of nanosilica particles reveal an increase in the peak current with a less negative value of the potential. The relationship between scan rate and peak potential direct to calculate a number of electrons and protons involved in the electro-oxidation process. A linear plot was obtained by varying the concentrations of the drug. A low detection limit value and good recovery values show us the applicability of the proposed electrode for pharmaceutical and urine samples analysis. Keywords: Nimesulide, Electro-oxidation, Nanosilica, Paste electrode, Electrochemistry, Pharmaceutical analysis