Eu-doped Mg-Al LDH As A Responsive Fluorescent Material And Its Interaction With Biomolecules

The work is aim at doping rare earth ions on the layeres of Mg-Al layered double hydroxide (LDH) and obtaining the Eu-doped Mg-Al LDH with fluorescent property. Variuos factors which affect the structure and fluorescent property of Eu-doped Mg-Al LDH have been systematically studied, and the optimum synthesizing conditions have been determined. Meanwhile, the reconstruction of calcinied Mg-Al-Eu ternary LDH in different pH solution system has been investigated. It was found that the structure and fluorescence of Mg-Al LDH can be recovered when the calcined LDH was immersed in different pH solution for three days, which is caused by the structural memory effect of LDH. While the structure and fluorescence of Mg-Al LDH changed obviously as the calcined sample was immersed in the solution for a week, which may be due to the corrosion of reacting solution on the recovered sample under the weak basic or acidic condition. Further, the study on the fluorescence of Eu-doped Mg-Al LDH sensitivity or response to biological molecules has been carried out, and the mechanism of the fluorescence of Eu-doped Mg-Al LDH sensitivity to biological molecules has been probed. Research indicated that the fluorescence of Eu-doped Mg-Al LDH was almost quenched and new emissions occurred when the Eu-doped Mg-Al LDH reacted with tryptophan, glutamic acid, and pyridine, respectively. The property based on the fluorescence of the Eu-doped Mg-Al LDH response to biological molecules make the Eu-doped LDH material potential application in biological probe, such as probing genic mutation and mismatch or absence of basic group, etc. This layered inorganic material has higher thermal stability and less toxicity compared with those of organic materials which are applied in biological probes.