Facile synthesis and characterisations of cobalt ferrite-silver-graphene oxide nanocomposite in enhancing electrochemical response capacity

In this report, cobalt ferrite nanoparticles (CoFe2O4 NPs) synthesised from the co-precipitation method were strongly connected with graphene oxide nanosheets (GO) via 'bridge molecules'-polyhexamethylene biguanide hydrochloride (PHMB)'. Silver (Ag) NPs were grown on the surface of CoFe2O4-GO nanocomposites to improve the electrical conductivity and electrocatalytic ability of the proposed functional nanocomposites. Characteristics of the synthesised materials were investigated via x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The obtained results demonstrate that the CoFe2O4-Ag-GO nanocomposites could significantly improve the adsorption ability and electron transfer between electrode and analytes owing to the synergetic effect of Ag NPs, CoFe2O4 NPs, and GO. The prepared CoFe2O4-Ag-GO nanocomposites showed the highest electrochemical response for chloramphenicol antibiotic detection, with current intensity response (similar to 24.4 mu A) being 3.25 and 2.57 times higher than that of CoFe2O4 NPs (7.5 mu A) and CoFe2O4-GO (9.5 mu A), respectively. The calibration plot is linear in the 1-50 mu M CAP concentration range, with a detection limit of 0.1 mu M. With excellent electrochemical properties, the CoFe2O4-Ag-GO nanocomposites are expected to be a potential candidate for advanced electrochemical sensing applications.