Efficacy of clay materials for ciprofloxacin antibiotic analysis in urine and pharmaceutical products

Ciprofloxacin (CIPRO) is a second-line antibiotic that belongs to the fluoroquinolone class. Over the years, the consumption of fluoroquinolones has increased exponentially due to their efficacy in treating several common infections. However, the increase in its residues can endanger human health and ecosystems, which requires its monitoring through the development of sophisticated technologies. In this study, a novel sensor for highly selective and rapid detection of CIPRO is fabricated. A facile strategy was employed to fabricate the electrode by impregnation of clay mineral on carbon paste electrode (Clay/CPE). The morphological features of the provided sensor were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Moreover, the electrochemical characterization of the Clay/CPE was performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with unmodified electrode, the oxidation peak current of CIPRO greatly increased at Clay/CPE indicating the excellent ability to promote electron transfer. Electrochemical measurements have been carried out using differential pulse voltammetry (DPV). Under optimized experimental conditions, the oxidation peak current was linear to the concentration of CIPRO in the range from 2.0 x 10(-7) to 5.0 x 10(-5) mol/L (r(2) = 0.98) with a detection limit of 4.6 x 10(-8) mol/L (3 x sigma/P). The practical applicability of the as prepared sensor was tested in the spiked human urine and pharmaceutical tablets with good recoveries. The work presented herein was significant as it can serve as tools for the analysis of antibiotics in wastewaters prior to being discharged into the environment since this kind of antibiotics can cause bacterial and genetic resistance in microbial populations present in water bodies, which can negatively affect human health.