A novel sensor based on electropolymerization of β-cyclodextrin and L-arginine on carbon paste electrode for determination of fluoroquinolones.

An electrochemical sensor for fluoroquinolones (FQs) based on polymerization of β-cyclodextrin (β-CD) and L-arginine (L-arg) modified carbon paste electrode (CPE) (P-β-CD-L-arg/CPE) was built for the first time. Synergistic effect of L-arg and β-CD was used to construct this sensor for quantification of these important antibiotics. Scanning electron microscope (SEM) image shows that polymer of β-CD and L-arg has been successfully modified on electrode. Electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) further indicate that polymer of β-CD and L-arg efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analyte and electrode. Under the optimized conditions, this modified electrode was utilized to determine the concentrations of ciprofloxacin, ofloxacin, norfloxacin and gatifloxacin. The differential pulse voltammogram (DPV) exhibits the oxidation peak currents were linearly proportional to their concentration in the range of 0.05-100 μM for ciprofloxacin, 0.1-100 μM for ofloxacin, 0.1-40 μM for norfloxacin and 0.06-100 μM for gatifloxacin, respectively. This method was also successfully used to detect the concentrations of each drug in pharmaceutical formulations and human serum samples. In addition, this proposed fluoroquinolones sensor exhibited good reproducibility, long-term stability and fast current response.