Cuprous Oxide/Nitrogen-doped Graphene Nanocomposites as Electrochemical Sensors for Ofloxacin Determination

Cu2O/nitrogen-doped grapheme(NG) nanocomposite material was prepared via a facile one step chemical reduction and characterized by means of X-ray diffraction(XRD) and scanning electron microscopy(SEM). A new electrochemical sensor was then fabricated by coating Cu2O/nitrogen-doped graphene nanocomposite with Nafion on glassy carbon electrode(Cu2O/NG/Nafion/GCE). The electrochemical response of this modified electrode toward ofloxacin was examined by cyclic voltammetry. The results indicate that Cu2O/NG/Nafion composite-modified electrode exhibits higher catalytic activity in the electrochemical oxidation of ofloxacin compared with glassy carbon electrode(GCE), Cu2O/Nafion modified electrode(Cu2O/Nafion/GCE), and N-doped graphene/Nafion modified electrode(NG/Nafion/GCE). Under optimal conditions, the peak current was found to be linearly proportional to the concentration of ofloxacin in the 0.5-27.5 mu mol/L and 27.5-280 mu mol/L ranges with a lower detection limit of 0.34 mu mol/L, higher sensitivity of 39.32 mu A.L.mmol(-1) and a shorter reaction time of less than 2 s. In addition, Nafion can enhance the stability of the modified electrode and prevent some negative species. Thus the modified electrode exhibits good selectivity and a long working life. The Cu2O/NG/Nafion composite modified electrode shows promising application in electrochemical sensors, biosensors, and other related fields because of its excellent properties.