"On-On-Off" Recyclable Fluorescence Battery for Direct and Selective Detection of Glyphosate and Cu²

Residues of environmental organophosphorus pesticides (OPs) will seriously endanger human health. Most reported OP sensors utilized the restrictions capacity of OPs on the catalytic capacity of acetylcholinesterase (AChE) to acetylthiocholine chloride (ATCh), which suffers from high costs, weak stability, long reaction time, and unrecyclable. Herein, a recyclable strategy was proposed for selective and sensitive detection of glyphosate (Gly). The weak fluorescence of UIO-66-NH₂ at 450 nm was enhanced almost 10-fold after reacting with Gly because of the rotation-restricted emission enhancement mechanism. Moreover, inspired by the process of charging and discharging the batteries, we introduced Cu²⁺ to chelate with Gly. Because of the strong chelation between Cu²⁺ and Gly, the Gly was removed from UIO-66-NH₂, which resulted in the quenching of fluorescence intensity and making UIO-66-NH₂ recycle. This method proposed is fast, recyclable, easily conducted, and with a low 0.33 μM LOD in dd H₂O based on 3σ/S. The recovery rates of Gly in tap water ranged from 93.07 to 104.35% within a satisfied 7.75% RSD. The Cu²⁺ LOD is 0.01 mM based on 3σ/S and 94.37-118.34% recovery rates within 6.48% RSD in tap water. We believe that the findings in this work provide a meaningful and promising strategy to detect Gly and Cu²⁺ in real samples. This sensor first successfully achieves the recycling use of the material in OP fluorescence detection, which greatly decreases the cost of the designed sensor and reduces the possibility of secondary pollution to the environment, broadens a new circulation dimension of fluorescence detection methods in detecting OPs, and has the potential to remove glyphosate from water. It also provides a method to utilize functionalized metal-organic frameworks to establish various sensors.