Preparation Of NaTb(SO₄)₂ And Tb₂O₂SO₄ Based On Tb(?)/tb(?)Redox Pair And Fluorescence Detection Of Biomolecules

The accurate and sensitive detection of active molecules with redox properties is of practical significance in the fields of biological analysis,medicine,environmental protection and the food industry.Fluorescence detection has the advantages of high sensitivity,rapid response and convenient operation.Tb is a rare earth element with variable valence.Its fluorescence intensity is closely related to the valence.The new Tb-containing inorganic nanoparticles have attracted widespread attention.However,the current mechanism behind Tb-containing fluorescent probes is still limited to the antenna effect between various sensitizers and Tb3+.From the perspective of the Tb(?)/Tb(?)redox pair,it has not yet been developed to make full use of it.The unique nature of Tb detection strategy,especially for the detection of redox active molecules(such as H2O2,GSH/VC).In addition,the variable valence of Tb ions endows some Tb-containing nanomaterials with mimic enzyme activity,which can be used for colorimetric detection of active molecules(such as GSH).And low-toxicity Tb-containing nanoenzymes also play an active role in tumor treatment.In this project,we designed and synthesized a kind of nano-fluorescent material based on Tb(?)/Tb(?)redox pair luminescence switch,used for the detection of redox active molecules,and aimed at the enzymatic activity of Tb-containing inorganic nanomaterials in tumors.Active attempts have been made in the treatment of oxidative stress.The specific research contents are as follows:1.NaTb(SO4)2 nano-materials were prepared by solvothermal method,and spherical Tb2O2SO4 nanoparticles were obtained by high-temperature calcination in an air atmosphere at 900?.The prepared NaTb(SO4)2 spherical nanoparticles have a diameter of about 300 nm,and the main phase is hexagonal crystal phase.The size of Tb2O2SO4 is about 260 nm,which is smaller than that of NaTb(SO4)2,and the surface of the particles becomes rough after calcination,and the phase has also changed.2.In the fluorescence performance test,when excited with 379 nm wavelength,the emission spectrum of NaTb(SO4)2 has emission peaks at 491 nm,545 nm and 580 nm.Tb2O2SO4 still has the same emission peak position,but the fluorescence intensity Decline.XPS data show that there are mixed valence states of Tb(?)and Tb(?)in the two materials,and the two valence states of Tb exhibit different luminous intensities.The luminescent Tb(?)/Tb(?)redox electron pair is used for the detection of redox molecules.Take the common hydrogen peroxide(H2O2),reduced glutathione(GSH)and ascorbic acid(VC)as examples.In the detection of H2O2,due to the addition of H2O2,the fluorescent Tb(?)is oxidized to non-fluorescent Tb(?),causing fluorescence quenching,thereby realizing the "turn-off" mode fluorescence detection of the oxidative active molecule H2O2.In the detection of GSH,the NaTb(SO4)2-Fe3+-GSH system was established.On the basis of the energy transfer between Fe3+and Tb causing NaTb(SO4)2 fluorescence quenching,the addition of GSH affects the energy between Fe3+ and Tb transfer to restore the fluorescence of the system.In addition,Tb2O2SO4 can directly detect reducing GSH/VC through the valence transition of Tb(?)?Tb(?).So far,the "turn-on" mode fluorescence detection of the reductive active molecule GSH/VC using the Tb(?)/Tb(?)redox electron pair is realized.3.In the test of mimic enzyme properties,Tb2O2SO4 nanomaterials showed good properties of oxidase and peroxidase mimics.The color and absorbance of the Tb2O2SO4 oxidase substrate TMB and the oxidized product oxTMB were used to detect the reductive active molecule GSH,and the colorimetric detection of Tb2O2SO4 to GSH was realized.In the in vitro treatment experiment of tumor cells,Tb2O2SO4 was incubated with a variety of cancer cells for 24 hours,and the cytotoxicity was within a safe level,and under different pH conditions,safe doses of hydrogen peroxide showed certain lethality to cancer cells.