阅读说明：本技术 一种稀土超分子凝胶发光材料、其制备和应用 (Rare earth supermolecule gel luminescent material, preparation and application thereof ) 是由 王宏 张彬彬 董学林 周琪 于 2019-11-13 设计创作，主要内容包括：本发明属于功能性稀土荧光材料领域,具体涉及一种稀土超分子凝胶发光材料、其制备和应用。以5,5’,5”-(1,3,5-三嗪-2,4,6-三亚氨基)-三间苯二甲酸为有机配体,在加热条件下,利用该有机配体分子的π-π相互作用、氢键及其与稀土盐中稀土离子的配位作用,该有机配体与稀土离子结合并自组装形成稀土超分子凝胶发光材料。所形成的凝胶具有稀土特有的光发射,荧光单色性好,量子产率高。本发明的稀土超分子凝胶在加热或冷藏(0～90℃)、机械力或水分子刺激下仍能够保持稳定的光发射；并且所发明的稀土超分子凝胶能够在水相中简便、快速、准确地检测唾液酸,具有选择性好、灵敏度高、检测限低的优点。(The invention belongs to the field of functional rare earth fluorescent materials, and particularly relates to a rare earth supermolecule gel luminescent material, and preparation and application thereof. The preparation method comprises the steps of taking 5, 5' - (1,3, 5-triazine-2, 4, 6-trisamino) -tri-isophthalic acid as an organic ligand, and under the heating condition, utilizing pi-pi interaction of molecules of the organic ligand, hydrogen bonds and coordination of the organic ligand and rare earth ions in rare earth salt, and combining and self-assembling the organic ligand and the rare earth ions to form the rare earth supramolecular gel luminescent material. The formed gel has the special light emission of rare earth, good fluorescence monochromaticity and high quantum yield. The rare earth supermolecule gel can still keep stable light emission under heating or refrigeration (0-90 ℃), mechanical force or water molecule stimulation; the rare earth supermolecule gel can simply, quickly and accurately detect sialic acid in a water phase, and has the advantages of good selectivity, high sensitivity and low detection limit.)

1. A preparation method of a rare earth supermolecule gel luminescent material is characterized in that 5, 5' - (1,3, 5-triazine-2, 4, 6-triphenylamine) -tri-m-phthalic acid is used as an organic ligand, under the heating condition, pi-pi interaction of molecules of the organic ligand, hydrogen bonds and coordination of the hydrogen bonds and rare earth ions in rare earth salt are utilized, and the organic ligand is combined with the rare earth ions and self-assembled to form the rare earth supermolecule gel luminescent material.

2. The method of claim 1, wherein the rare earth salt is terbium chloride or europium chloride.

3. The method of claim 1 or 2, comprising the steps of:

(1) mixing an organic solution of 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid with a rare earth salt solution to obtain a mixed solution of an organic ligand and rare earth ions;

(2) mixing poor solvent of 5, 5' - (1,3, 5-triazine-2, 4, 6-three amino) -tri-isophthalic acid with the mixed solution of the organic ligand and rare earth ions, and heating to obtain the rare earth supramolecular gel luminescent material.

4. The method according to claim 3, wherein the 5, 5', 5 "- (1,3, 5-triazine-2, 4, 6-trisaminol) -tri-isophthalic acid of step (1) is mixed with rare earth ions in a rare earth salt in a molar ratio of 1:0.2 to 1: 20; the concentration of the organic solution of the organic ligand 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid is 10-50 mmoL/L; the final concentration of the rare earth ions in the mixed solution of the organic ligand and the rare earth ions is 10-80 mmol/L.

5. The method according to claim 3, wherein the organic solvent used in the organic solution is DMF and/or DMSO.

6. The method of claim 3, wherein the poor solvent for 5, 5', 5 "- (1,3, 5-triazine-2, 4, 6-trisylamino) -tri-isophthalic acid is one or more of methanol, ethanol and water.

7. The method according to claim 3, wherein the volume ratio of the poor solvent for 5, 5', 5 "- (1,3, 5-triazine-2, 4, 6-trisylamino) -tri-isophthalic acid to the mixed solution of the organic ligand and the rare earth ion is 9:1 to 1: 9.

8. The method according to claim 3, wherein the heating temperature in the step (2) is 50 to 100 ℃ and the heating time is 20 to 200 min.

9. The rare earth supramolecular gel luminescent material prepared by the preparation method of any one of claims 1 to 8.

10. Use of rare earth supramolecular gel light emitting material according to claim 9, for preparing fluorescent probe for detecting sialic acid.

Technical Field

The invention belongs to the field of functional rare earth fluorescent materials, and particularly relates to a rare earth supramolecular gel luminescent material, preparation and application thereof, and more particularly relates to a rare earth supramolecular metal gel luminescent material with luminescence stability based on an organic ligand 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminonaphthalene) -tri-isophthalic acid, and a preparation method and application thereof.

Background

The rare earth fluorescent material has important application in the fields of illumination, sensing, imaging, fluorescent marking, anti-counterfeiting and the like due to the advantages of excellent optical properties such as narrow emission peak, good fluorescence monochromaticity, large Stokes displacement, long fluorescence life and the like. The luminous intensity of the rare earth fluorescent material is easily affected by heat, water molecules and mechanical force, so that the luminous stability of the rare earth fluorescent material is insufficient, and the application of the rare earth fluorescent material in a temperature-variable environment and the like is limited.

In the past, scientists have made various efforts to improve the stability of light emission of rare earth luminescent materials, including fixing rare earth in a matrix such as a polymer, a film, zeolite, liquid crystal, etc. by a physical or chemical method. It is noted that these methods for improving stability usually require the rare earth ions to be loaded in the matrix after being combined with the ligand, and when the structure of such matrix is destroyed, the luminescence stability of the rare earth brought by the method is correspondingly lost. Rare earth luminescent gels have been reported to be prepared by co-doping rare earth ions and organic ligands in the gel network using a supramolecular self-assembly strategy, but rely on weak interactions to drive the structural collapse of the formed gel after temperature rise resulting in the disappearance of light emission Bhowmik S. (Chemical communications,2010,46, 8642-. In addition, in the method for improving the rare earth luminescence stability, a ligand matched with the energy of rare earth ions is generally required to be searched to form a rare earth luminescence complex, and then the rare earth luminescence complex is loaded in a matrix, so that the process is complicated. Therefore, designing a substrate which can match with the energy of rare earth ions, has an antenna effect and stabilizes the luminescent property of rare earth is still a great challenge at present.

Sialic acid is a monosaccharide with a nine-carbon backbone, which plays an important role in physiological and pathological processes, and abnormal expression and distribution of sialic acid on the cell surface or in body fluids are closely associated with various diseases, including cancer and diabetes, as well as cardiovascular and nervous system diseases. Therefore, it is of great significance to develop efficient detection methods for detecting sialic acid. Some methods such as colorimetric method, chromatographic method, enzymatic method and the like can be effectively used for sialic acid detection, but the methods have respective defects, such as the colorimetric method is easily interfered by a matrix and has low sensitivity, the chromatographic method needs high cost and needs professional operation, and the enzymatic method also has the problem of high test cost. Therefore, the luminescent sensor with high development sensitivity, simple operation and low cost for detecting sialic acid has good application prospect.

Disclosure of Invention

In view of the above drawbacks or needs for improvement of the prior art, the present invention provides a rare earth supramolecular gel light emitting material with luminescence stability, its preparation and application by using 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminonaphthalene) -tri-isophthalic acid (abbreviated as H in the present invention)₆L) is an organic ligand, under the heating condition, the organic ligand is combined with rare earth ions and self-assembled to form the rare earth supermolecule gel luminescent material by utilizing the pi-pi interaction of organic ligand molecules, hydrogen bonds and the coordination of the organic ligand molecules and the rare earth ions in rare earth salts, and the rare earth supermolecule gel can keep stable light emission property under the stimulation of heating or refrigeration (0-90 ℃), mechanical force and water molecules, so that the technical problems that the luminescent stability of the rare earth luminescent material in the prior art is poor or the stability improving process is complicated and the like are solved.

In order to achieve the above objects, according to one aspect of the present invention, a method for preparing a rare earth supramolecular gel light emitting material is provided, wherein 5, 5', 5 ″ - (1,3, 5-triazine-2, 4, 6-trisimino) -tri-isophthalic acid is used as an organic ligand, and under heating conditions, the organic ligand is combined with rare earth ions and self-assembled to form the rare earth supramolecular gel light emitting material by using pi-pi interaction, hydrogen bonds and coordination of rare earth ions in rare earth salts of the organic ligand molecules.

Preferably, the rare earth salt is terbium chloride or europium chloride.

Preferably, the preparation method comprises the following steps:

(1) mixing an organic solution of 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid with a rare earth salt solution to obtain a mixed solution of an organic ligand and rare earth ions;

(2) mixing poor solvent of 5, 5' - (1,3, 5-triazine-2, 4, 6-three amino) -tri-isophthalic acid with the mixed solution of the organic ligand and rare earth ions, and heating to obtain the rare earth supramolecular gel luminescent material.

Preferably, the 5, 5' - (1,3, 5-triazine-2, 4, 6-trisylamino) -tri-isophthalic acid in the step (1) is mixed with rare earth ions in rare earth salt according to a molar ratio of 1: 0.2-1: 20; the concentration of the organic solution of the organic ligand 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid is 10-50 mmoL/L; the final concentration of the rare earth ions in the mixed solution of the organic ligand and the rare earth ions is 10-80 mmol/L.

Preferably, the 5, 5' - (1,3, 5-triazine-2, 4, 6-trisylamino) -tri-isophthalic acid in the step (1) is mixed with rare earth ions in a rare earth salt according to a molar ratio of 1: 0.5-1: 15.

Preferably, the organic solvent used in the organic solution is DMF and/or DMSO.

Preferably, the poor solvent of 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminol) -tri-isophthalic acid is one or more of methanol, ethanol and water.

Preferably, the volume ratio of the poor solvent of the 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminoidene) -tri-isophthalic acid to the mixed liquid of the organic ligand and the rare earth ions is 9:1 to 1: 9.

Preferably, the heating temperature in the step (2) is 50-100 ℃; the heating time is 20-200 min.

Preferably, the heating temperature in the step (2) is 65-85 ℃; the heating time is 30-150 min.

According to another aspect of the invention, the rare earth supramolecular gel luminescent material prepared by the preparation method is provided.

According to another aspect of the invention, the application of the rare earth supramolecular gel luminescent material is provided, and the rare earth supramolecular gel luminescent material is used for preparing a fluorescent probe for detecting sialic acid.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

(1) the invention uses H₆And L is an organic ligand, and under the heating condition, the organic ligand is combined with rare earth ions to form a supramolecular gel material. At H₆Pi-pi interaction of L, hydrogen bond and H₆The L and the rare earth ions are self-assembled under the coordination action to form the rare earth supermolecule gel luminescent material, and the formed gel material has the unique light emission of rare earth, high luminous intensity, good fluorescence monochromaticity and high quantum yield.

(2) The rare earth supermolecule gel has stable light emission property, and the light emission intensity can still keep stable light emission property under the stimulation of heating or refrigeration (0-90 ℃), mechanical force and water molecules.

(3) The rare earth supramolecular gel material with luminescence stability provided by the invention is prepared without being loaded in a matrix to improve the stability, and the preparation method is simple and has high stability.

(4) The rare earth supermolecule gel xerogel powder has stronger light emission in aqueous solution and can quantitatively detect sialic acid with high sensitivity and high selectivity. Sialic acid can cause decrease of light emission intensity in the xerogel powder aqueous solution, and the sialic acid has concentration of 40-180 μ M to I₀I has a linear relationship (I)₀And I is the luminescence intensity of the probe when no sialic acid is added and when a certain concentration of sialic acid is added, respectively), and thus can be used for quantitatively detecting sialic acid. The quenching constant of the compound on sialic acid can be up to 86000M^-1The detection limit can be as low as 9.1 mu M, and the detection shows higher sensitivity on sialic acid. In the selective experiment of sialic acid structural analogues of fructose, glucose, mannose and galactose, only sialic acid can cause quenching of light emission, and other structural analogues cannot cause quenching of light emission. In addition to this, even the concentration of fructose, glucose, mannose and galactoseIs 100 times of sialic acid, does not change the quenching of the sialic acid to the luminescent material, and shows high selectivity for sialic acid detection.

(5) The rare earth supermolecule gel has the advantages that the market of the raw materials for preparing the rare earth supermolecule gel is easy to obtain, the price is low, the required amount of xerogel for sialic acid detection is small (for a rare earth supermolecule gel probe solution with the concentration of 10 mu g/mL, if the volume of the solution used for each detection is 1mL, the required mass of xerogel powder of the supermolecule gel is 10 mu g), and the problem of high sialic acid detection cost is expected to be solved.

Drawings

FIG. 1 shows terbium H₆And the comparison graph of the luminescence spectrum of the L in the solution state and the gel state.

FIG. 2 shows Tb H₆L supramolecular gel electron microscopy pictures. The organic solvent is DMF, methanol, H₆The concentration of L is 12mmol/L, and the concentration of terbium chloride is 12 mmol/L.

FIG. 3 shows Tb H₆And the supramolecular gel formed by the L in different solvents emits a fluorescence spectrum.

FIG. 4 is H₆And the L and different terbium ion salt solutions are self-assembled to form a supermolecular gel.

FIG. 5 is H₆And L and different rare earth ions are self-assembled to form a supermolecular gel.

FIG. 6 is a fluorescence spectrum of the effect of rare earth ion type on the emission of light from rare earth supramolecular gel.

FIG. 7 is terbium H₆And the fluorescence spectrum of the L supramolecular gel is stable to the temperature (0-90 ℃).

FIG. 8 shows Tb H₆Fluorescence spectrum of L supramolecular gel responding to mechanical force.

FIG. 9 shows Tb H₆The fluorescence spectrum of the L supermolecule xerogel powder aqueous solution, the consumption of the xerogel is 10 mug.

FIG. 10 shows terbium H₆And (3) a light emission stability fluorescence spectrum diagram of the L supermolecule xerogel powder aqueous solution.

FIG. 11 is terbium H₆And the luminous response graph of the L supermolecule xerogel powder to sialic acid with different concentrations in aqueous solution.

FIG. 12 is terbium H₆And (3) a fitting curve graph of the luminous intensity of the L supermolecule xerogel powder in the aqueous solution and the sialic acid concentration.

FIG. 13 shows terbium H₆And (3) selectively measuring sialic acid detection of the L supermolecule xerogel powder in an aqueous solution.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention provides a preparation method of a rare earth supermolecule gel luminescent material, which is characterized in that 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminol) -tri-isophthalic acid is taken as an organic ligand, under the heating condition, the organic ligand is combined with rare earth ions and self-assembled to form the rare earth supermolecule gel luminescent material by utilizing the pi-pi interaction of the organic ligand molecules, hydrogen bonds and the coordination of the organic ligand molecules and the rare earth ions in rare earth salts.

The organic ligand 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid adopted by the invention contains carboxyl and can be coordinated and combined with rare earth ions, the high conjugated structure of the organic ligand enables the organic ligand to have good pi-pi stacking effect in the gelling process, and carboxyl and amino which do not participate in coordination can provide intermolecular hydrogen bonding binding sites in the gelling process. In the experimental process, the heating can promote the pi-pi interaction of the organic ligand molecules and the hydrogen bond interaction between molecules to be greatly enhanced, and meanwhile, the coordination of the organic ligand molecules and rare earth salt is more obvious in performance compared with the situation that the organic ligand molecules and the rare earth salt are not heated under the heating condition, and the number of the complexing sites is obviously increased. Therefore, heating is a necessary condition for promoting the organic ligand and the rare earth salt of the present invention to form the rare earth supramolecular gel light-emitting material.

In some embodiments, the rare earth salt is terbium chloride.

In some embodiments, the preparation method specifically comprises the following steps:

(1) mixing an organic solution of 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid with a rare earth salt solution to obtain a mixed solution of an organic ligand and rare earth ions;

(2) mixing poor solvent of 5, 5' - (1,3, 5-triazine-2, 4, 6-three amino) -tri-isophthalic acid with the mixed solution of the organic ligand and rare earth ions, and heating to obtain the rare earth supramolecular gel luminescent material.

In some embodiments, the 5, 5' - (1,3, 5-triazine-2, 4, 6-trisylamino) -tri-isophthalic acid in step (1) is mixed with rare earth ions in a rare earth salt in a molar ratio of 1:0.2 to 1: 20; preferably 1:0.5 to 1:15, and more preferably 1:0.6 to 1: 8. The concentration of the organic solution of the organic ligand 5, 5' - (1,3, 5-triazine-2, 4, 6-triamino) -tri-isophthalic acid is 10-50 mmoL/L, and preferably 20-45 mmoL/L. The organic solvent adopted in the organic solution is DMF and/or DMSO; the final concentration of the rare earth ions in the mixed solution of the organic ligand and the rare earth ions is 10-80 mmol/L, and preferably 12-75 mmol/L.

In some embodiments, the poor solvent for the 5, 5', 5 "- (1,3, 5-triazine-2, 4, 6-trisaminol) -tri-isophthalic acid is one or more of methanol, ethanol, and water.

In some embodiments, the volume ratio of the poor solvent of 5, 5' - (1,3, 5-triazine-2, 4, 6-trisaminoidene) -tri-isophthalic acid to the mixed solution of the organic ligand and the rare earth ion is 9:1 to 1:9, and preferably ranges from 9:1 to 4: 6.

In some embodiments, the heating temperature in the step (2) is 50-100 ℃, preferably 65-85 ℃; the heating time is 20-200 min, preferably 30-150 min.

The invention also provides the rare earth supramolecular gel luminescent material prepared by the preparation method. The rare earth supermolecule gel can keep stable light emission property under the conditions of heating or refrigeration (0-90 ℃), mechanical force and water molecule stimulation.

The invention also provides application of the rare earth supramolecular gel luminescent material, which can be used for preparing a fluorescent probe for detecting sialic acid. The xerogel powder prepared from the rare earth supermolecule gel can be used for quantitatively detecting sialic acid in aqueous solution with high sensitivity.

Organic ligand H used in the invention₆The chemical structural formula of L is as follows:

in a preferred embodiment of the invention, H is first introduced₆Mixing the organic solution of L and the solution of rare earth ion salt according to a certain proportion and concentration, and then mixing with H₆And mixing poor solvents of L, and heating to obtain the supermolecule rare earth gel luminescent material. The heating serves here to promote the coordination of the organic ligands with the rare earth ions, the pi-pi of the organic ligands and the formation of hydrogen bonding interactions. H₆The organic solvent in the organic solution of L is DMF or DMSO, and other organic solvents such as formamide are tried in the experimental process of the invention, so that gel cannot be formed. The preferable rare earth ion is terbium ion, and the prepared rare earth supermolecule gel material has the best performance. In experiments, other rare earth ions with good self-luminescence performance, such as europium ions and samarium ions, have been tried, but under the same conditions, the prepared gel material does not emit light or has poor luminescence performance. Derived therefrom, H₆L ligand absorbs light to transfer energy to rare earth ions, and H is in the process of energy transfer₆The energy level matching of L and rare earth ions is important, H of the invention₆L is only optimally matched with the energy level of the rare earth terbium ion, and the luminous performance is possibly poor due to the variety of any rare earth ion.

The preparation process of the gel material is particularly critical, and the conditions such as the concentration, the proportion, the feeding sequence and the like of the organic ligand and the rare earth ions have great influence on the gel formation and the gel forming performance. The invention selects proper concentration, proportion and charging sequence, and controls specific preparation conditions and process parameters, so that the rare earth supermolecule gel material with luminescence stability and sialic acid detection function can be successfully prepared.

The rare earth supramolecular gel luminescent material provided by the invention is simple and controllable in preparation process, the obtained rare earth supramolecular gel has rare luminescence stability, and the luminescence intensity can still keep stable light emission under the stimulation of heating or refrigeration (0-90 ℃), mechanical force and water molecules. The rare earth supermolecule gel xerogel powder has stronger light emission in water environment, can quantitatively detect sialic acid with high sensitivity and high selectivity, and is used for preparing a fluorescent probe for detecting sialic acid.

The rare earth supermolecule gel system comprises an organic ligand, rare earth ions and an organic solvent, and is formed by depending on pi-pi interaction and hydrogen bond interaction of the organic ligand and coordination interaction of the organic ligand and the rare earth ions. The formed gel has the special light emission of rare earth, good fluorescence monochromaticity and high quantum yield. The invention has the advantages that: the rare earth supermolecule gel can still keep stable light emission under heating or refrigeration (0-90 ℃), mechanical force or water molecule stimulation; the rare earth supermolecule gel can simply, quickly and accurately detect sialic acid in a water phase, and has the advantages of good selectivity, high sensitivity and low detection limit.

The following are examples: