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

Abstract

In this study, the main purpose is to fabricate a sensitive and selective electrochem. sensor through the multi-walled carbon nanotube-graphite/Ag electrode (MWCNTs-G/Ag). The application of this sensor was developed for the detn. of diclofenac sodium in pharmaceutical dosage form, urine and human blood plasma. MWCNTs-graphite mixt. improved the electroactive surface area due to its porous structure and a remarkable increase in the peak currents was obsd. 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 max. current response for the sensor in the Britton-Robinson buffer soln. can be obtained in pH 3. The prepd. sensor showed good std. calibration curves during 3 consecutive days over the concn. 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, resp. [on SciFinder(R)]