Voltammetric determination of ofloxacin by using a laser-modified carbon glassy electrode

A novel electrochemical sensor is described for the determination of ofloxacin (OFL) in environmental water samples. A laser-modified glassy carbon electrode (LGCE) was structured and characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. The increase in electrochemical activity is due to a moderate increase in the surface roughness and to the presence of functional groups on the LGCE. Under optimal conditions (viz. a pH value of 5.5, a laser power of 1.8 W and an action time of 40 s), the sensor is capable of detecting OFL by differential pulse voltammetry at a working potential of +0.91 V (versus Ag/AgCl). Response is linear from 0.25 to 200 μM for OFL concentration range, and the detection limit is 75 nM (at S/N = 3). Removal of oxygen from samples is not required. The sensor was successfully applied to the determination of OFL in spiked groundwater, tap water and wastewater samples, with apparent recoveries from 94.0 to 108.0% and a relative standard deviation of less than 4.8%."