Electrochemical Detection of Ciprofloxacin Using a Functionalized Graphene Oxide Nanocomposite Sensor

Abstract

Widespread misuse of ciprofloxacin (CIP) threatens ecosystems and human health by fostering antibiotic resistance. This work develops an electrochemical sensor with high sensitivity for CIP detection by altering an electrode made of glassy carbon with a cobalt phthalocyanine-functionalized graphene oxide (CoPc/GO) nanocomposite. The CoPc/GO synergy significantly improved the electroactive area, electron transfer, and CIP adsorption. Using square-wave voltammetry, the sensor achieved a broad linear range (0.01–10.0 μM) with a 2.1 nM detection limit. It demonstrated excellent repeatability (RSD < 3.5%), reproducibility (RSD < 4.8%), stability over four weeks, and strong resistance to interferences (<5% signal change). Successful application in spiked wastewater and river water samples, with recoveries of 97.2–103.5%, confirms its practicality for environmental monitoring of antibiotic residues