Ultrasensitive monitoring of Ciprofloxacin with green reduced graphene oxide@clay composite

The accumulation of harmful residuals can lead to voluminous environmental problems and then negatively affect human health. For this purpose, it is necessary to focus on the development of a rapid and sensitive strategy for its monitoring. In this work, a green, fairly fast, inexpensive and sensitive electrochemical sensor was developed to determine and monitor Cipro residues in various samples such as environmental resources, wastewater, urine, and drug formulations (Flonox 500 Aflox 500 and Cifloxine 250). It consists of a carbon paste electrode (CPE) modified with clay-supported reduced graphene oxide composite (GrGO/CL@CPE). The rGO was prepared using green and easily chemically converted GO (electrochemically prepared) to rGO nanosheets based on glucose (G) as a green reducing agent (GrGO). The proposed sensor demonstrates a high electro-oxidation signal compared with other based sensors, and the oxidation potential was found to be reduced by around 35 mV. The GrGO/CL@CPE was used for monitoring Cipro in the range of 0.05–10 μM in phosphate buffer at a biological pH of 7 (PB_7) and it offered a low detection limit (DL) (S/N=3) of 0.048 μM. Furthermore, it was found to be capable of detecting Cipro in pronounced samples with excellent results, offering promising prospects for actual clinical assays.