Pharmaceutica Analytica Acta

Abstract

Application of Carbon Nanotube-Graphite Mixture for the Determination of Diclofenac Sodium in Pharmaceutical and Biological Samples

Abdolmajid Bayandori Moghaddam, Ali Mohammadi and Mozhgan Fathabadi

In this study, the main purpose is to fabricate a sensitive and selective electrochemical sensor through the multiwalled carbon nanotube-graphite/Ag electrode (MWCNTs-G/Ag). The application of this sensor was developed for the determination of diclofenac sodium in pharmaceutical dosage form, urine and human plasma. MWCNTs-graphite mixture improved the electroactive surface area due to its porous structure and a remarkable increase in the peak currents was observed. It demonstrated a catalytic effect and speeded up the rate of redox process. Application of MWCNTs-G/Ag resulted in a sensitivity augmentation. It is found that a maximum current response for the sensor in the Britton-Robinson buffer solution can be obtained in pH 3. The prepared sensor showed good standard calibration curves during 3 consecutive days over the concentration range of 45-2000 ng/mL and RSD values ranging from 1.95–7.11%. The limit of quantitation and detection limit were 45 and 15 ng/mL, respectively.