Electrochemical detection of ciprofloxacin based on graphene modified glassy carbon electrode

A cheap, convenient and sensitive electrochemical method was developed for the determination of ciprofloxacin (CIP), one of quinolones, based on a graphene (GNs) modified glassy carbon electrode (GCE). Graphene oxide (GO) was prepared via improved Hummer method, and GNs were synthesised via reduction of GO using the hydrothermal method. Graphene modified GCE was obtained by dropping the GNs dispersion onto the surface of GCE and dried in air. The as prepared electrode was not only characterised by Fourier transform infrared, X-ray diffraction and SEM but also used to analyse the electrochemical behaviour of CIP. The results show that, under the optimal conditions, the oxidation peak current of CIP displays a linear response to its concentration in the range between 0.5 and 200 mmol L-1 with a correlation coefficient R-2 = 0.9970. The detection limit is 0.02 mmol L-1 at a signal/noise of 3. The analytical performance of this sensor has been evaluated for the detection of ciprofloxacin hydrochloride drugs sold in the market. The relative standard deviation (RSD) of each sample is <5%, indicating that the as established analysis method has high accuracy and operability, which can be used for the rapid detection of the sample.