A Magnetic Fluorescent Molecularly Imprinted Chitosan/Nitrogen-Doped Carbon Dot/Fe₃O₄ Nanohybrid for Selective Fluorescence Detection of Ciprofloxacin in Aqueous Systems
Abstract
Antibiotic contamination in aquatic environments has become a significant environmental concern due to the persistence of pharmaceutical residues, biological activity, and their contribution to antimicrobial resistance. Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, is frequently detected in wastewater and natural water systems because conventional treatment processes are insufficient for complete removal. Therefore, the development of rapid, sensitive, and selective detection platforms for ciprofloxacin monitoring is highly desirable. In this study, a multifunctional magnetic fluorescent molecularly imprinted nanohybrid based on chitosan, nitrogen-doped carbon dots (N-CDs), and Fe₃O₄ nanoparticles was developed for selective fluorescence detection of ciprofloxacin. The designed nanohybrid combines the fluorescence properties of N-CDs, magnetic separation capability of Fe₃O₄ nanoparticles, functional advantages of chitosan, and selective molecular recognition ability of molecular imprinting technology. The fabricated nanohybrid was characterized using UV–visible spectroscopy, fluorescence spectroscopy, FTIR, XRD, SEM, TEM, and elemental analysis. The incorporation of N-CDs provided strong fluorescence emission, while Fe₃O₄ nanoparticles contributed magnetic functionality. FTIR analysis confirmed the presence of characteristic functional groups, and XRD verified the crystalline structure of magnetite nanoparticles. The sensing performance was evaluated through ciprofloxacin-induced fluorescence quenching. The nanohybrid exhibited concentration-dependent fluorescence reduction, achieving a linear detection range of 5–100 µM, with R² = 0.992 and a detection limit of 0.85 µM. Molecular imprinting significantly enhanced selective recognition, showing higher response toward ciprofloxacin compared with tetracycline, amoxicillin, and sulfamethoxazole. The developed magnetic fluorescent molecularly imprinted nanohybrid provides a promising platform for selective antibiotic monitoring and advanced environmental sensing applications.
How to Cite
Gaurav , "A Magnetic Fluorescent Molecularly Imprinted Chitosan/Nitrogen-Doped Carbon Dot/Fe₃O₄ Nanohybrid for Selective Fluorescence Detection of Ciprofloxacin in Aqueous Systems", Vol. 2, Issue 10, 25-01-2025, pp. 109-124.
