Visual fluorescence detection of ciprofloxacin by Zn-metal-organic framework@nanocellulose transparent films based on aggregation-induced emission

The invention and production of Ciprofloxacin (CIP) have a positive impact on medical treatment, but the overuse of CIP is also harmful to the environment. In this paper, we prepared a novel film material for detection of CIP by in situ synthesis of zinc-based metal-organic framework (Zn-BDC) on TEMPO-oxidized cellulose nanofibers (TOCNF). The nanoscale Zn-BDC were uniformly distributed on the TOCNF that was beneficial to realize the transparency and functionality of Zn-BDC@TOCNF whose transparency was up to 87 %. Zn-BDC@TOCNF showed no fluorescence itself while showed bright fluorescence upon the contact of CIP, which was proposed as the aggregation-induced emission (AIE) of CIP that defused and assembled in the Zn-BDC@TOCNF. There was a certain linear relationship between fluorescence intensity and concentration of CIP (R² = 0.994, LOD = 0.083 μM). In the detection process, CIP could still fluoresce in Zn-BDC@TOCNF even if it was interfered by other ions and small biological molecules, and the weak acid environment was conducive to AIE of CIP. Generally, it was of great significance to establish a rapid and effective monitoring mechanism for CIP in water for environmental protection and ecological balance.