A Recyclable Eu3+-Functionalized Dual-Emissive Metal-Organic Framework for Portable, Rapid Detection and Efficient Removal of Malachite Green

An europium-functionalized, dual-emissive, metal-organic fluorescent sensor (EuUCNDA) was constructed via post-synthetic modification of a UiO-66-type precursor through coordination interactions.EuUCNDA displayed extremely highly selectivity and sensitivity for malachite green (MG) with a low detection limit of 13.01 nM, a wide linear concentration range (0–50 μM), excellent anti-interference properties, a rapid response (<1 min), and the possibility to be recycled. The good sensing performance of EuUCNDA enables the practical detection of MG in fish pond water and grass carps with good recoveries. Moreover,EuUCNDA can be reused for sensing MG, the fluorescence intensity can be restored over 90% after 7 cycles. Furthermore, EuUCNDA-embedded paper-based sensors combined with smartphone imaging afford portable, visual monitoring of MG in real samples. Notably, besides the good sensing performance, EuUCNDA could efficiently remove MG from water. Hence, this work provides a recyclable and sensitive fluorescent sensor for portable, visual, rapid detection and efficient removal of MG.