DOE-Optimized Fluorescent Sensor Based on CQDs@Ag@Cu for Sensitive Detection of Cefixime in Wastewater

Cefixime, a prominent member of the cephalosporin antibiotic family, is widely employed to treat various bacterial infections. Continuous monitoring of its concentration in biological fluids is essential to ensure therapeutic efficacy and minimize potential adverse effects. In this study, a novel fluorescent sensing platform was developed based on carbon quantum dots (CQDs) synthesized from Artemisia absinthium biomass, subsequently functionalized with copper and silver ions (CQDs@Ag@Cu) via a one-pot hydrothermal method. The synthesized nanocomposite demonstrated significant fluorescence enhancement in the presence of cefixime, which is attributed to specific interactions between the antibiotic molecules and the doped CQDs. The optimal fluorescence response was observed at pH 6.5, with minimal interference from other coexisting analytes. The sensor exhibited a linear dynamic range from 117.6 to 529.21 µM and a detection limit as low as 50.5 µM. Practical applicability was confirmed through analysis of cefixime in spiked wastewater samples, underscoring its potential utility in biomedical monitoring and clinical diagnostics. These findings endorse the eco-friendly nanoprobe as a promising tool for therapeutic drug monitoring.