Fluorescence quenching-based sensing of ofloxacin using dual-nuclear terbium complex†

Ofloxacin (OFX), a potent antibacterial agent widely used in clinical practice, is commonly employed to treat various bacterial infections. However, its overuse has raised significant concerns due to its adverse effects on human health and environmental safety, particularly in terms of antibiotic resistance and environmental contamination. To address this issue, a novel dual-nuclear terbium complex, [Tb₂(DMOAP)₂(DMF)₄Cl₄] (DMOAP = 4-hydroxy-3,5-dimethoxybenzaldehyde), was synthesized as a highly sensitive luminescent probe for OFX detection. Experimental results demonstrated a notable decrease in the fluorescence intensity of complex 1 upon the addition of OFX, indicating a strong fluorescence quenching effect. Quantitative analysis revealed a fluorescence quenching constant of 3.3 × 10⁴ M⁻¹ and a detection limit of 0.3 μM for OFX, showcasing the excellent performance of this complex as a fluorescence probe for OFX detection. In practical applications, the probe successfully detected OFX in purchased drugs with high accuracy, demonstrating its potential in real-world environmental monitoring.