A circularly polarized luminescent material, its preparation method and application

Abstract

The present invention discloses a circularly polarized luminescence material based on a solid thin film of biological macromolecules, and a preparation method and application thereof. The present invention realizes supramolecular chiral transfer and amplification of CPL signals in a solid thin film system established by a biological macromolecule complex, a cationic surfactant, and an organic dye molecule. The thin film can be stretched to three times its initial length, and as the stretching ratio increases, the CPL signal is gradually amplified. Moreover, the preparation method is simple and highly operable.

Description

Technical Field

[0001] The present invention belongs to the field of circularly polarized luminescence materials, and particularly relates to a circularly polarized luminescence material based on a solid film of biological macromolecules, a preparation method thereof, and applications thereof. Background Art

[0002] Circularly polarized luminescence (CPL) is a unique chiral optical property of chiral luminescence systems and has become one of the most useful tools for studying the excited-state properties of chiral materials. Chiral optical materials with CPL activity have broad application prospects in many research fields such as three-dimensional display, enantioselective recognition of enantiomers, and non-invasive biomedical diagnosis, and have received extensive attention. In recent years, it has been reported that CPL-active materials can be constructed by using simple self-assembly strategies through various non-covalent interactions between molecules, and can be conveniently regulated by external stimuli such as light irradiation, changes in pH value or temperature, and application of electric and magnetic fields.

[0003] Inspired by nature, many organisms can respond to mechanical strain and convert this stimulus into chemical or electrical signals. Scientists have gradually developed mechanochemistry to explore the effects of mechanical stimuli on optical responses or chemical signals. In recent years, the application of mechanical forces in chemical systems, whether in the form of mechanical stretching, shearing, grinding, or sonication, has brought many fascinating development prospects. At the same time, considering the inevitability of mechanical forces in chemical systems and the wide application of mechanical properties, mechanical response performance is becoming a particularly attractive property of smart materials. However, so far, there are few reported studies on converting mechanical stimuli into chiral optical signals. Summary of the Invention

[0004] The object of the present invention is to propose a method for realizing amplification of circularly polarized luminescence by mechanical stretching in a biological macromolecule thin film material. The present invention doped non-chiral cationic fluorescent dye molecules such as 4',6-diamidino-2-phenylindole dihydrochloride (DAPI), berberine hydrochloride (BCH), acridine orange (AO), and ethidium bromide (EB) into a solid film to explore the effect of mechanical stretching on chiral signals.

[0005] In order to achieve the above object of the invention, the present invention provides the following technical solutions:

[0006] A circularly polarized luminescence thin film material based on a solid film of biological macromolecules is prepared by a method including the following steps:

[0007] 1) Dissolve a certain proportion of chiral biological macromolecules, quaternary ammonium salt surfactants with different carbon chain lengths, and non-chiral cationic dyes in an aqueous solution, stir evenly at room temperature, and obtain a complex precipitate through an ion exchange reaction; centrifuge to collect the precipitate, and freeze-dry to obtain a solid powder;

[0008] 2) Wash the solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, filter and then dry it under vacuum to obtain the complex;

[0009] 3) Dissolve the obtained complex in an organic solvent, and gradually volatilize the solvent at room temperature to finally obtain a complex film with stretchable properties.

[0010] The method further includes: testing the CPL spectrograms of the complex films before and after stretching in different dye-doped complex film systems.

[0011] The multiple of the stretching can be 1 - 3 times the initial length of the film.

[0012] In the above method step 1), the chiral biopolymers include proteins, nucleic acids, lipids, carbohydrates, etc.;

[0013] In the above method step 1), the quaternary ammonium salt surfactants with different carbon chain lengths include dodecyl dimethyl ammonium chloride, tetradecyl dimethyl ammonium chloride, hexadecyl dimethyl ammonium chloride, octadecyl dimethyl ammonium chloride, C n TAC (n = 12, 14, 16, 18), dodecyl dimethyl ammonium bromide, tetradecyl dimethyl ammonium bromide, hexadecyl dimethyl ammonium bromide, octadecyl dimethyl ammonium bromide, and C n TAB (n = 12, 14, 16, 18);

[0014] In the above method step 1), the achiral dye molecules include at least one of cationic dyes such as 4',6-diamidino-2-phenylindole dihydrochloride (DAPI), berberine hydrochloride (BCH), acridine orange (AO), ethidium bromide (EB), thioflavin, and safranine;

[0015]

[0016] In the above method step 1), the molar ratio of the chiral biopolymer to the quaternary ammonium salt surfactant can be 0.5 - 3.

[0017] In the above method step 1), the molar ratio of the chiral biopolymer to the achiral cationic dye can be 1 / 16 - 1, specifically 1:16, 1:8, 1:4, 1:2, or 1:1.

[0018] In the above method step 2), the washing is performed at least twice.

[0019] In the above method step 3), the organic solvent includes ethanol, chloroform, dichloromethane, ethyl acetate, methanol, and a mixed solvent of two solvents.

[0020] The present invention also provides a method for mechanically stretching and amplifying circularly polarized luminescence.

[0021] The method for mechanically stretching and amplifying circularly polarized luminescence provided by the present invention is to mechanically stretch the stretchable composite film prepared by the above method to achieve amplification of circularly polarized luminescence.

[0022] The multiple of the mechanical stretching can be 1 - 3 times the initial length of the film.

[0023] The present invention realizes supramolecular chiral transfer and amplification of CPL signals in a solid film system established by a biomacromolecule complex, a cationic surfactant, and an organic dye molecule. This film can be stretched to three times its initial length, and as the stretching ratio increases, the CPL signal is gradually amplified. Moreover, the preparation method is simple and highly operable.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] Based on chiral biomacromolecule DNA, the present invention successfully prepares a stretchable composite film. This method has the characteristics of simple process, easy operation, easy regulation, and strong practicability. This dye-doped DNA composite film not only provides a good template for chiral transfer but also helps to quantify the chiral transfer from chiral molecules to achiral molecules according to macroscopic mechanical stimuli, and has broad application prospects in optical display and materials science. Description of the Drawings

[0026] Figure 1 Pictures of DNA composite films doped with different dyes under visible light and ultraviolet light irradiation as the stretching ratio increases.

[0027] Figure 2 CPL spectra of DAPI dye-doped DNA composite film before and after stretching.

[0028] Figure 3 CPL spectra of BCH dye-doped DNA composite film before and after stretching.

[0029] Figure 4 CPL spectra of AO dye-doped DNA composite film before and after stretching.

[0030] Figure 5 CPL spectra of EB dye-doped DNA composite film before and after stretching. Detailed Embodiments

[0031] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. Unless otherwise specified, the methods are all conventional methods. Unless otherwise specified, the raw materials can all be obtained from public commercial channels.

[0032] The biomacromolecule DNA used in the following examples, CAS No. 68938-01-2, was purchased from Acros Organics, product number 406251000.

[0033] Example 1. DAPI Dye-Doped Composite Film System

[0034] 1. Weigh 0.5 g of biomacromolecule DNA, 0.4 g of dodecyldimethylammonium chloride, and 27.73 mg of DAPI and place them in a 250 mL round-bottom flask. Add 100 mL of water to dissolve, and after uniform mixing, a precipitate is obtained.

[0035] 2. Then, centrifuge to collect the precipitate at a speed of 10,000 r / min and freeze-dry to obtain a solid powder. Next, wash the obtained solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, repeat twice, and after filtration, vacuum dry to obtain the composite.

[0036] 3. Dissolve the obtained composite in an organic solvent (a mixed solvent of CHCl3 / EtOH with a volume ratio of 1:1 - 5:1), and gradually volatilize the solvent at room temperature to finally obtain a composite film with stretchable properties.

[0037] Figure 1 In [a], there are pictures of the DAPI dye-doped composite film under visible light and ultraviolet light irradiation as the stretching ratio increases. It can be clearly seen that the length of the film can be stretched to three times the original, and there is no obvious color change.

[0038] Figure 2 These are the CPL spectra of the DAPI dye-doped composite film before and after stretching. It can be seen that in the case of no stretching, a weak negative CPL signal is detected at 470 nm; as the stretching degree increases, the CPL signal of the composite film gradually increases, and the amplification of circularly polarized luminescence is realized in the DAPI dye-doped composite film system through mechanical stretching.

[0039] Example 2. BCH Dye-Doped Composite Film System

[0040] 1. Weigh 0.5 g of biomacromolecule DNA, 0.4 g of dodecyldimethylammonium chloride, and 37.18 mg of BCH and place them in a 250 mL round-bottom flask. Add 100 mL of water to dissolve, and after uniform mixing, a precipitate is obtained.

[0041] 2. Then centrifuge to collect the precipitate at a speed of 10,000 r / min, and freeze-dry to obtain a solid powder. Next, wash the obtained solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, repeat twice, and vacuum-dry after filtration to obtain the complex.

[0042] 3. Dissolve the obtained complex in an organic solvent (a CHCl3 / EtOH mixed solvent with a volume ratio of 1:1 - 5:1), and gradually evaporate the solvent at room temperature to finally obtain a complex film with stretchable properties.

[0043] Figure 1 In Figure b are pictures of the BCH-dye-doped complex film under visible and ultraviolet light irradiation as the stretching ratio increases. It can be clearly seen that the length of the film can be stretched to three times its original length, and there is no obvious color change.

[0044] Figure 3 Figure shows the CPL spectra of the BCH-dye-doped complex film before and after stretching. It can be seen that without stretching, a weak negative CPL signal is detected at 540 nm; as the stretching degree increases, the CPL signal of the complex film gradually increases, and amplification of circularly polarized luminescence is achieved in the BCH-dye-doped complex film system through mechanical stretching.

[0045] Example 3. AO-dye-doped complex film system

[0046] 1. Weigh 0.5 g of biological macromolecule DNA, 0.4 g of dodecyl dimethyl ammonium chloride, and 36.99 mg of AO and place them in a 250 mL round-bottom flask, add 100 mL of water to dissolve, and obtain a precipitate after uniform mixing.

[0047] 2. Then centrifuge to collect the precipitate at a speed of 10,000 r / min, and freeze-dry to obtain a solid powder. Next, wash the obtained solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, repeat twice, and vacuum-dry after filtration to obtain the complex.

[0048] 3. Dissolve the obtained complex in an organic solvent (a CHCl3 / EtOH mixed solvent with a volume ratio of 1:1 - 5:1), and gradually evaporate the solvent at room temperature to finally obtain a complex film with stretchable properties.

[0049] Figure 1 In Figure c are pictures of the AO-dye-doped complex film under visible and ultraviolet light irradiation as the stretching ratio increases. It can be clearly seen that the length of the film can be stretched to three times its original length, and there is no obvious color change.

[0050] Figure 4CPL spectra of the AO-doped composite film before and after stretching. It can be seen that without stretching, a weak negative CPL signal was detected at 630 nm; as the stretching degree increased, the CPL signal of the composite film gradually enhanced, and the amplification of circularly polarized luminescence was achieved in the AO-doped composite film system through mechanical stretching.

[0051] Example 4. EB-doped composite film system

[0052] 1. Weigh 0.5 g of biopolymer DNA, 0.4 g of didodecyldimethylammonium chloride, and 39.43 mg of EB and place them in a 250 mL round-bottom flask. Add 100 mL of water for dissolution, and after uniform mixing, a precipitate is obtained.

[0053] 2. Then centrifuge to collect the precipitate at a speed of 10,000 r / min and freeze-dry to obtain a solid powder. Next, wash the obtained solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, repeat twice, and after filtration, dry it under vacuum to obtain the composite.

[0054] 3. Dissolve the obtained composite in an organic solvent (a CHCl3 / EtOH mixed solvent with a ratio of 1:1 - 5:1), and through gradual evaporation of the solvent at room temperature, a composite film with stretchable properties is finally obtained.

[0055] Figure 1 In d, pictures of the EB-doped composite film under visible light and ultraviolet light irradiation with the increase of the stretching ratio are shown. It can be clearly seen that the length of the film can be stretched to three times the original length, and there is no obvious color change.

[0056] Figure 5 CPL spectra of the EB-doped composite film before and after stretching. It can be seen that without stretching, a weak negative CPL signal was detected at 670 nm; as the stretching degree increased, the CPL signal of the composite film gradually enhanced, and the amplification of circularly polarized luminescence was achieved in the EB-doped composite film system through mechanical stretching.

Claims

1. A method for preparing a circularly polarized luminescence thin film material based on a biomacromolecule solid thin film, comprising the following steps: 1) Dissolve a chiral biomacromolecule, a quaternary ammonium salt-type surfactant, and an achiral cationic dye in an aqueous solution, stir evenly at room temperature, and obtain a complex precipitate through an ion exchange reaction; Centrifuge to collect the precipitate and freeze-dry to obtain a solid powder; 2) Wash the solid powder with chloroform and ether, dissolve it in chloroform, pour it into ether to precipitate, filter and then dry it under vacuum to obtain a complex; 3) Dissolve the obtained complex in an organic solvent, and gradually volatilize the solvent at room temperature to finally obtain a complex thin film with stretchable properties; In the step 1), the chiral biomacromolecule is biomacromolecule DNA with a CAS number of 68938-01-2; In the step 1), the quaternary ammonium salt-type surfactant is didodecyldimethylammonium chloride; In the step 1), the achiral cationic dye is selected from at least one of the following: 4',6-diamidino-2-phenylindole dihydrochloride, berberine hydrochloride, acridine orange, ethidium bromide; 2. The preparation method according to claim 1, characterized in that: In the step 1), the molar ratio of the chiral biomacromolecule to the achiral cationic dye is 1 / 16 to 1.

3. The preparation method according to claim 1, characterized in that: In the step 2), the washing is performed at least twice.

4. The preparation method according to claim 1, characterized in that: In the step 3), the organic solvent is ethanol, chloroform, dichloromethane, ethyl acetate, methanol, or a mixed solvent of two solvents.

5. The preparation method according to claim 1, characterized in that: The method further includes: stretching the obtained complex thin film with stretchable properties and testing the CPL spectrograms of the thin film before and after stretching.

6. A circularly polarized luminescence thin film material based on a biomacromolecule solid thin film prepared by the method according to any one of claims 1-5.

7. A method for mechanically stretching and amplifying circularly polarized luminescence, which is to mechanically stretch the circularly polarized luminescence thin film material based on a biomacromolecule solid thin film according to claim 6 to achieve amplification of circularly polarized luminescence.

8. The method according to claim 7, wherein: The multiple of the mechanical stretching is 1-3 times the initial length of the thin film.

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