Electrochemical sensor based on electro-polymerization of β-cyclodextrin and reduced-graphene oxide on glassy carbon electrode for determination of gatifloxacin

A novel electrochemical sensor for gatifloxacin based on one-pot electro-polymerization of β-cyclodextrin (β-CD) and reduced-graphene oxide (rGO) modified glassy carbon electrode (GCE) (β-CD/rGO/GCE) was built for the first time. Scanning electron microscope (SEM) image and Infrared spectroscopy (IR) show that polymer of β-cyclodextrin and reduced graphene oxide (rGO) has been successfully modified on electrode. The electrochemical properties of this polymer were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The optimization of the electro-polymerized cycle, the pH of supporting electrolyte and the accumulation potential and time were discussed in details. Under optimum conditions, the differential pulse voltammogram (DPV) exhibited the oxidation peak currents were linearly proportional to gatifloxacin concentrations in the range from 0.05 μM to 150 μM with a sensitivity of 0.33 μA μM−1. This electrochemical sensor had a low detection limit of 0.02 μM (S/N = 3). Moreover, this proposed sensor exhibited good reproducibility, long-term stability and fast current response. To further study the practical applicability of the proposed sensor, the modified electrode was successfully applied to detect gatifloxacin in tablets and human urine samples.