A turn-on fluorescence probe Eu3+ functionalized Ga-MOF integrated with logic gate operation for detecting ppm-level ciprofloxacin (CIP) in urine.

The threatening of antibiotic drugs for human and environment is being paid more and more attention. Ciprofloxacin (CIP), a strong quinolone antibiotic drug widely used in therapeutic treatments, is the most frequently detected in surface waters among the fluoroquinolones, which represents animal and human health risks. A novel highly fluorescent Ga-based hybrid (Eu3+@1) has been synthesized based on metal-organic framework (MOF) by encapsulating lanthanide cations Eu3+ in its channels. The as-synthesized compound possesses excellent water and pH-independent stability. It displays week red luminescence of Eu3+ in itself and can sense the CIP concentration as turn-on fluorescent probe in the human urine. With addition of CIP, the evident luminescence enhancement is clearly observed from the Eu3+@1. Linear correlation between the fluorescence intensity and the concentration of CIP is investigated, proving the excellent performance of Eu3+@1 in the detection of CIP with linear range (0.01-0.2 mg/mL) and low detection limit (2.4 ppm or 2.4 μg/mL). The response time is also very quick, less than 3 min. Based on these findings, we introduce AND logic gate strategy to the probe. The input of the logic gates (0, 1), (0, 1, 1), (1, 1, 1) cause the different outputs of CIP determination "LOW" (<25 ppm),"NORMAL" (25-76 ppm), "HIGH" (>76 ppm), respectively. The novel strategy can be applied for a real-time CIP concentration evaluation by intelligent discrimination.