A nanostructured suitable platform based on multi wall carbon nanotubes and graphene nano sheets composite for determination of mefenamic acid

A mefenamic acid sensor was prepared by the modification of a glassy carbon electrode (GCE) with graphene nano-sheets (Gr) and multi wall carbon nanotubes (MWCNT). The designed sensor (MWCNT/Gr/GCE) indicated an electrocatalytic behaviour when applied for mefenamic acid (MFA) oxidation due to good conductivity, low electron transfer resistance and catalytic effect. The suggested sensor revealed a lower overvoltage and enhanced current compared with bare GCE for the oxidation of MFA. The observations indicated that the oxidation potential of MFA is decreased more than 200 mV using the designed sensor. The percentages of MWCNTs and Gr nano materials, and pH solution were optimized. Under the optimum conditions, some kinetic parameters, such as surface coverage in a 0.5 mM [Fe(CN)6]3-/4- solution was obtained by cyclic voltammetric method. The diffusion coefficient of MFA (D) was calculated to be 2.88?10-6 cm2 s-1 by chronoamperometeric technique. The MWCNT/Gr/GCE sensor exhibited a linear dynamic range for MFA (2? 100 ?M) with a detection limit of 0.66 ?M by differential pulse voltammetry (DPV) technique. This sensor revealed a suitable applicability for determination of MFA in real samples (drug samples and serum solutions).