Carbon dots derived from green jujube as chemosensor for tetracycline detection

The detection of tetracycline antibiotics in environmental waters is crucial due to their widespread use, persistence, and potential toxicity. Herein, highly fluorescent blue-emitting carbon dots (B-CDs) were synthesized via a facile, green solvothermal approach using green jujube as the carbon source and ethylenediamine as the nitrogen dopant. The B-CDs exhibited an exceptional quantum yield of 24.7% in ethanol along with excitation-dependent photoluminescence from surface defects. Remarkably, the B-CDs displayed high selectivity and sensitivity toward tetracycline antibiotics through static quenching and inner filter effects. A linear correlation between fluorescence quenching and tetracycline concentration enabled quantitative detection down to 0.062 μM. The feasibility of using B-CDs for antibiotic sensing in real waters was validated by spike-recovery experiments achieving 91.5-100.8% recoveries. The findings provide insights into natural product-derived carbon nanomaterials while offering an eco-friendly sensing platform with potential for on-site antibiotic monitoring and environmental remediation.