Fabricating multifunctional low-toxicity ratiometric fluorescent probe for individual detection of Cu2+/glutamate and continuous sensing for glutamate via Cu2+-based platform.

Herein, a multifunctional ratiometric fluorescent (RF) probe Fe-MIL-88NH2@RhB was fabricated for individual detection of Cu2+/Glu and continuous sensing of Glu based on unique coordination principle by encapsulating RhB into the porous of metal-organic-framework-Fe-MIL-88NH2. Designed Fe-MIL-88NH2@RhB platform could selectively identify Cu(II)/Glu accompanying a turn-off/turn-on fluorescent behavior with good linearity. Moreover, if the Fe-MIL-88NH2@RhB/Cu2+ is treated with Glu continuously, the quenching fluorescence of this platform (after Cu2+ sensing at blue emission) would be further in turn restored. Utilizing Fe-MIL-88NH2@RhB probe, the imaging of intracellular Cu(II) and Glu in living A549 cells was successful conducted through divisional channels with a satisfactory low cytotoxicity, meanwhile, the sensing results of Glu in serum by the molecular logic gate was also superior, which may use for development of an medical occupational tool for amyotrophic lateral sclerosis tentative diagnosis. In addition, the MOF shows di-modal response (color and lumescence) to Cu2+ and Glu with excellent selectivity against a wide range of other interference analytes, and the corresponding portable low-toxicity on-line test strips for Cu2+ and Glu recognize has exhibited a remarkable visually chromogenic phenomena, which may utilize for monitoring these contaminants in real water sample. Finally, the feasibility of probe to monitor Cu2+ and Glu in foodstuffs was also evaluated.