Novel poly-l-lysine/carboxyl-group enriched graphene oxide/modified electrode preparation, characterization and applications for the electrochemical determination of meloxicam in pharmaceutical tablets and blood serum

Abstract

Electrochemical determination of meloxicam (MLC) was successfully determined at a poly-L-lysine (PLL)/carboxylated graphene oxide (GO–COOH)/modified glassy carbon electrode (GCE) by cyclic voltammetry (CV) and differential pulse voltammetric (DPV) techniques. The fabricated film characterizations were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The PLL/GO–COOH/GCE was employed for the electrocatalytic oxidation of MLC and the oxidation current of MLC significantly increased when compared to the bare GCE, which clearly shows that the modified electrode shows better electrocatalytic activity than the unmodified GCE. The linear range of the determination of MLC has to be 4 to 104 μM. The low limit of detection (LOD) and sensitivity was found as 0.87 μM and 0.228 μA μM⁻¹ cm⁻². The analytical performance of this proposed sensor has been evaluated in commercially available pharmaceutical tablets and the practicality of the proposed sensor further demonstrated in a real blood serum sample. The obtained results for commercially available tablets were almost equal to the labelled claim of the tablets; from these results it was clearly evident that the proposed electrode shows good catalytic activity towards MLC.