Surface Coating Of Nano Luminescent Material GdPO₄·H₂O:Eu³⁺ And Its Interaction With Protein

Protein is not only the basic organic matter of cells,but also an important component of life and the cornerstone of life materials.Exploring the interaction between proteins and small molecules is to explore life activities at the molecular level.Compared with other biological detection methods,fluorescence technology has obvious advantages such as fast response,high sensitivity and strong selectivity.It has important practical significance for monitoring and treating some diseases.Due to the unique 4f level orbit of rare earth materials,rare earth nano luminescent materials have unique luminescent properties,high sensitivity and strong penetration ability.Fluorescent probes made of rare earth nano luminescent materials can effectively overcome many defects in the application of organic dyes,fluorescent proteins and quantum dots in biomedical field.Therefore,they have great application potential in biological imaging,medical detection and so on.Rare earth nanoparticles are mostly hydrophobic and have no functional groups to connect with biomolecules.Their application in the field of biology and medicine is greatly limited.Therefore,the research and development of nano fluorescent materials with good water solubility and biocompatibility is to solve the bottleneck problem of current scientific research.Based on this,this thesis synthesized Gd PO₄·H₂O:Eu³⁺phosphor,explored the best synthesis conditions,sought the method to solve the poor water solubility of phosphor,and explored the interaction mechanism between phosphor and protein.This thesis mainly studies from the following aspects:（1）Using Eu³⁺as activator and Gd PO₄as matrix,orange red nano phosphor Gd PO₄·H₂O:Eu³⁺was prepared by hydrothermal method.The microstructure,morphology and luminescence properties of phosphors were characterized and analyzed by means of X-ray diffraction（XRD）,field emission scanning electron microscopy（SEM）and transmission electron microscopy（TEM）,infrared spectroscopy（FT-IR）,fluorescence spectroscopy（FL）and vibrating sample magnetometer（VSM）.The optimal doping amount of Eu³⁺was explored,and the concentration quenching and energy transfer mechanism between phosphor nanoparticles were studied.（2）The surface of rod-shaped nano phosphor Gd PO₄·H₂O:Eu³⁺@PEG was coated with polyethylene glycol（PEG）,and the rod-shaped Gd PO₄·H₂O:Eu³⁺@PEG with good water solubility was obtained.The surface coating mechanism and the luminescence and magnetic properties of nano phosphor were studied.（3）Based on the molecular interaction theory,the calibration process of bovine serum albumin（BSA）and human serum albumin（HSA）by Gd PO₄·H₂O:Eu³⁺@PEG at room temperature was studied.At the same time,the interaction between BSA and HSA and the conformation of BSA and HSA by Gd PO₄·H₂O:Eu³⁺@PEG at different temperatures were studied.