Sensitive electrochemical determination of rifampicin using gold nanoparticles/poly-melamine nanocomposite

In this work, a novel electrochemical sensing platform was successfully prepared by electrodeposition of gold nanoparticles on the electropolymerized layer of poly-melamine modified pre-anodized glassy carbon electrode. The surface morphology and electrochemical behaviour of the modified electrode (PMel-Au-nano/GCE*) were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The proposed sensor remarkably increased the oxidation responses of rifampicin (RIF) associated with a significant decrease in its peak over-potentials of about 0.10 V based on the integration of the beneficial effects of a conductive PMel (with excellent electrocatalytic activity) and gold nanoparticles (with prominent electrochemical properties and large surface area), which exhibits the properties of their individual components with synergistic effects. The results demonstrated that voltammetric determination of RIF achieved favourably and the modified electrode represents two oxidation peaks for rifampicin at potentials approximately 0.09 V (peak 1) and 0.70 V (peak 2) in phosphate buffer solution with a linear range of 0.08-15.00 mu M and a detection limit of 0.03 mu M. The developed sensor is stable, reproducible and feasible for long-term use in biological samples with satisfactory results for RIF detection.