Simultaneous determination of paracetamol and ciprofloxacin in biological fluid samples using a glassy carbon electrode modified with graphene oxide and nickel oxide nanoparticles.

A simple and highly selective electrochemical method using a glassy carbon electrode (GCE) modified with graphene oxide (GO) and nickel oxide nanoparticles (NiONPs) was developed for the simultaneous determination of paracetamol (PAR) and ciprofloxacin (CIP). The electrochemical characterisation of the modified GCE was performed by cyclic voltammetry and electrochemical impedance spectroscopy. The morphological characterisation of the GO and NiONPs was performed by scanning electron microscopy and transmission electron microscopy. Under optimised conditions, using square wave voltammetry, the simultaneous determination of PAR and CIP using the NiONPs-GO-CTS: EPH/GCE sensor shows a linear concentration range from 0.10 to 2.9µmolL-1 and 0.040-0.97µmolL-1, with detection limits of 6.7 and 6.0 nmol L-1, respectively. The NiONPs-GO-CTS: EPH/GCE sensor showed good reproducibility, repeatability and stability. Furthermore, the proposed method was successfully applied for the simultaneous determination of PAR and CIP in synthetic biological fluid samples.