A method for regulating the wavelength of emission of a fat amine type unconventional fluorescent polymer sequentially red-shifted

Abstract

The present application relates to the technical field of fluorescent sensor, in particular to a method for regulating the wavelength emission of aliphatic amine type unconventional fluorescent polymer to sequentially red shift. At present, there is a lack of method for regulating the fluorescent color of aliphatic amine type non-conjugated fluorescent polymer to sequentially change from blue light to red light. In view of the above technical problem, the present application provides a method for regulating the wavelength emission of aliphatic amine type unconventional fluorescent polymer to sequentially red shift. The method is for aliphatic amine type unconventional fluorescent polymer, by sequentially changing the length of straight-chain secondary amine alcohol carbon chain, the type of substituent group on the amino group and the relative position of amino group and alkyl alcohol hydroxyl group in the reaction raw material, so that the aliphatic amine type unconventional fluorescent polymer sequentially red shifts according to the adjustment order. The method is simple, controllable and environmentally friendly, and has good application prospect in the fields of fluorescent sensor, biomedical imaging, photodynamic therapy and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluorescent sensor, in particular to a method for regulating wavelength order red shift of fat amine type unconventional fluorescent polymer emission. BACKGROUND

[0002] In recent years, with the rapid development of polymer light-emitting materials, traditional conjugated fluorescent materials (such as polymers containing fused ring aromatic hydrocarbons or aromatic heterocyclic structures) gradually expose limitations such as complex preparation process, poor biocompatibility, and insufficient environmental stability due to their dependence on π-π conjugated system light-emitting mechanism. Under this background, a class of non-conjugated polymers without fused ring or aromatic heterocyclic structure has attracted widespread attention due to its unique aggregation state photoluminescence phenomenon, and is called unconventional new light-emitting material. This kind of material produces fluorescence through intramolecular or intermolecular non-conjugated action (such as steric hindrance, hydrogen bond, cluster effect, etc.) in the aggregation state, showing a completely different light-emitting mechanism from traditional materials, and has significant advantages such as simple preparation, adjustable structure, excellent hydrophilicity, and outstanding biocompatibility, becoming an ideal candidate material in the fields of fluorescent sensor, biomedical imaging, photodynamic therapy, etc.

[0003] Current research shows that non-conjugated polymers (such as polyamide, polyethyleneimine, polyether, etc.) can realize light emission through the following mechanisms:

[0004] Clusteroluminescence: The lone pair electrons (such as N, O atoms) or functional groups (such as hydroxyl, amino) in the molecular chain form a dense electron cloud in the aggregation state, and produce fluorescence through space conjugation or charge transfer.

[0005] Dynamic bond interaction: Dynamic crosslinking such as hydrogen bond, ionic interaction can regulate the light-emitting performance.

[0006] Excited state intramolecular proton transfer (ESIPT): Some polymers containing amino or hydroxyl groups can achieve Stokes shift through proton transfer.

[0007] Such materials have been successfully applied in biological labeling, cell imaging and drug delivery systems. For example, polyethyleneimine (PEI) derivatives show potential in in vivo imaging due to their good water solubility and low toxicity.

[0008] Although unconventional light-emitting materials have significant advantages, their light-emitting color regulation ability is severely limited, which is specifically manifested in:

[0009] Narrow emission wavelength range: Existing materials are mostly concentrated in the blue or green light region (400-550nm), and lack of regulation means covering the full spectrum of visible light (especially red light, 600-700nm).

[0010] Unclear structure-property relationship: the luminescence mechanism of non-conjugated systems is complex, and the effects of functional group types, molecular chain topological structures (such as linear, branched, hyperbranched), and aggregation state microenvironments (such as crystallinity and interchain spacing) on luminescent color have not been systematically elucidated.

[0011] Regulation difficulties of aliphatic amine polymers: although aliphatic amine type (such as tertiary amine groups) polymers have excellent biocompatibility and pH responsiveness, their luminescent wavelengths are mostly limited to the blue-green light region (450-520 nm), and strategies for red shift to the red light region through chemical modification or physical means have not been reported.

[0012] Insufficient dynamic range: existing methods (such as changing solvent polarity and regulating pH value) can only achieve limited wavelength shift (<50 nm), which is difficult to meet the needs of wide spectral coverage for applications such as multi-color labeling and anti-counterfeiting coding.

[0013] The root cause of the above problems lies in the fundamental difference between the luminescence mechanism of non-conjugated systems and traditional materials:

[0014] Lack of energy level regulation of non-conjugated backbone: traditional π-π conjugated materials can directly regulate the energy gap by extending the conjugation length or introducing substituents, while non-conjugated systems rely on local electronic states and cluster effects, making energy level regulation significantly more difficult.

[0015] Coupling effects of multiple factors: luminescent properties are affected by multiple factors such as electronic properties of functional groups, molecular chain conformation, and aggregation state packing mode, and changes in a single structural parameter cannot achieve a wide range of wavelength regulation. SUMMARY

[0016] The existing problem in the prior art is that there is currently a lack of a method for regulating the fluorescence color of non-conjugated fluorescent polymers to sequentially change from blue light to red light. In order to solve the above technical problems, the present application provides a method for regulating the emission wavelength of aliphatic amine type non-traditional fluorescent polymers to sequentially red shift, the aliphatic amine type non-traditional fluorescent polymer comprises the following structural general formula:

[0017]

[0018] The above aliphatic amine type non-traditional fluorescent polymer is a product obtained by room temperature click reaction of the hydroxyl group of an aliphatic primary amine alcohol or an aliphatic secondary amine alcohol with the alkyne group of ethylene glycol dipropargylate or acetyl amide dipropargylate, the value of n is determined by the amount of raw materials and reaction conditions in the click reaction, in the above structural general formula, the value of m is in the range of 2-6, m is an integer, R1 includes straight chain alkyl, cycloalkyl or aryl;

[0019] By sequentially changing the value of m or the type of R1 substituent, the maximum absorption peak and emission peak of the above aliphatic amine type non-traditional fluorescent polymer sequentially red shift.

[0020] Preferably, the aliphatic secondary amine alcohol comprises the following structural formula:

[0021]

[0022] R1 in the above structural formula comprises a linear alkyl group, a cyclic alkyl group or an aryl group; the aliphatic secondary amine alcohol is a linear secondary amine alcohol, and m is an integer ranging from 2 to 6.

[0023] Preferably, R1 comprises one of a phenyl group, a cyclohexyl group, a methyl group, an ethyl group, an isopropyl group and a tert-butyl group.

[0024] Preferably, the aliphatic primary amine alcohol comprises the following structural formula:

[0025]

[0026] In the above structural formula, m is an integer ranging from 2 to 6.

[0027] Preferably, for Formula I, when m = 2 and the molar ratio of the aliphatic secondary amine alcohol to ethyleneglycol dipropargylate is 1:1, the maximum excitation wavelength and the maximum emission wavelength of the obtained aliphatic amine type unconventional fluorescent polymer are sequentially red-shifted when R1 is sequentially adjusted to be a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a cyclohexyl group or a phenyl group.

[0028] Preferably, for Formula II, when R1 is a methyl group and the molar ratio of the aliphatic secondary amine alcohol to acetylamide dipropargylate is 1:1, the maximum excitation wavelength and the maximum emission wavelength of the obtained aliphatic amine type unconventional fluorescent polymer are sequentially red-shifted when m is sequentially adjusted to be m = 4 or 3 or 2.

[0029] Preferably, for Formula III, when the molar ratio of the aliphatic primary amine alcohol to ethyleneglycol dipropargylate is 1:1, the maximum excitation wavelength and the maximum emission wavelength of the obtained aliphatic amine type unconventional fluorescent polymer are sequentially red-shifted when m is sequentially adjusted to be m = 2 or 3 or 4 or 6.

[0030] The present application has the following beneficial effects:

[0031] (1) The present application is directed to aliphatic amine type unconventional fluorescent polymers, and by sequentially changing the length of the carbon chain of the secondary amine alcohol and the type of the substituent group on the amino group in the reaction raw material, the fluorescent color of the specific aliphatic amine type unconventional fluorescent polymer is sequentially red-shifted according to the adjustment order, and the fluorescent color of the specific aliphatic amine type unconventional fluorescent polymer appears from the blue light region to the red light region, and even to the near-infrared region.

[0032] (2) The method for adjusting the fluorescent color of the aliphatic amine type unconventional fluorescent polymer is simple, controllable and environmentally friendly.

[0033] (3) The development of the present application will solve the core problem of single light-emitting color of aliphatic amine non-traditional light-emitting materials, and provide key technical support for its application in the following fields:

[0034] Multicolor anti-counterfeiting label: high security coding is achieved by combining polymers of different light-emitting colors;

[0035] In vivo multi-channel imaging: fluorescent markers covering blue light to red light can avoid the interference of biological tissue autofluorescence;

[0036] Photodynamic therapy: red light region emitting materials have deeper tissue penetration ability, which can improve the treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 : is the emission spectrum of LP-1, LP-2, LP-3, LP-4, LP-5 and LP-6 in Example 1 at their respective maximum excitation wavelengths.

[0038] Figure 2 : is the emission spectrum of LP-7, LP-8 and LP-9 in Example 2 at their respective maximum excitation wavelengths.

[0039] Figure 3 : is the emission spectrum of BP-1, BP-2, BP-3 and BP-4 in Example 4 at their respective maximum excitation wavelengths.

[0040] Figure 4 : is the visible light and ultraviolet light irradiation diagram of LP-1, LP-2, LP-3 and LP-4 in Example 1 mixed with silica gel powder at a mass ratio of 1:50 respectively.

[0041] Figure 5 : is the application effect diagram of using the DMF solution formed by LP-1, LP-2, LP-3 and LP-4 in Example 1 as an anti-counterfeiting label.

[0042] Figure 6 : Fluorescent emission spectrum of LP-6 and non-traditional linear fluorescent polymer obtained in Comparative Example 1.

[0043] Figure 7 : Fluorescent emission spectrum of LP-9 and non-traditional linear fluorescent polymer obtained in Comparative Example 2. DETAILED DESCRIPTION

[0044] The present application will be described in detail below in conjunction with the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present application, and are not a limitation on the scope of the present application.

[0045] The activated alkyne monomers used in the following examples of the present application can be purchased on the market or easily synthesized, wherein the activated alkyne monomers in the following examples of the present application It can be synthesized according to the method reported in the reference (ACS Appl. Polym. Mater. 2024, 6, 4127-4137).

[0046] Example 1

[0047] Ethylene glycol dipropynate (0.222 g, 1 equiv) was sequentially mixed and stirred with N-benzylethanolamine (0.151 g, 1 equiv), 2-(cyclohexylamino)ethanol (0.143 g, 1 equiv), 2-methylaminoethanol (0.075 g, 1 equiv), 2-(ethylamino)ethyl-1-ol (0.089 g, 1 equiv), 2-(isopropylamino)ethanol (0.103 g, 1 equiv), and 2-(tert-butylamino)ethanol (0.117 g, 1 equiv) at 25 °C for 6 h. After the reaction was completed, the four reaction solutions were subjected to hexane precipitation, filtration, and drying to obtain six groups of non-traditional linear fluorescent polymers with different structures: LP-1, LP-2, LP-3, LP-4, LP-5, and LP-6.

[0048] Fluorescence spectroscopy analysis revealed a significant red shift in the maximum absorption and emission peaks of LP-1, LP-2, LP-3, LP-4, LP-5, and LP-6 in solid-state conditions. The maximum excitation wavelengths of LP-1, LP-2, LP-3, LP-4, LP-5, and LP-6 in solid-state were 450 nm, 458 nm, 468 nm, 475 nm, 496 nm, and 550 nm, respectively, and the maximum emission wavelengths were 488 nm, 502 nm, 511 nm, 530 nm, 548 nm, and 592 nm, respectively, corresponding to blue, cyan, green, yellow, orange, and red light (as per the instruction manual). Figure 1 As shown in the figure, this method can regulate the emission color of aliphatic amine-type non-traditional fluorescent polymers by adjusting the substituents on the amino groups of the secondary amine alcohol monomer, so that the emission color of the obtained aliphatic amine-type non-traditional linear fluorescent polymer gradually changes from the blue light region to the red light region. Electron cloud density order: phenyl < cyclohexyl < methyl < ethyl < isopropyl < tert-butyl.

[0049] The chemical formulas involved in the above reaction are as follows:

[0050]

[0051] Example 2

[0052] Ethylene glycol dipropynate (0.222 g, 1 equiv) was sequentially mixed and stirred with 4-methylamino-1-butanol (0.117 g, 1 equiv), 3-(methylamino)-1-propanol (0.089 g, 1 equiv), and 2-methylaminoethanol (0.075 g, 1 equiv) at 25 °C for 6 h. After the reaction was completed, the three reaction solutions were precipitated with n-hexane to obtain three non-traditional linear fluorescent polymers with different structures: LP-7 (m=4), LP-8 (m=3), and LP-9 (m=2). Fluorescence spectroscopy analysis revealed a significant red shift in the maximum absorption and emission peaks of LP-7, LP-8, and LP-9 in solid-state applications. The maximum excitation wavelengths of LP-7, LP-8, and LP-9 in solid-state were 468, 579, and 588 nm, respectively, and the maximum emission wavelengths were 515, 619, and 628 nm, respectively, corresponding to cyan, red, and red light-emitting materials (as per the attached specification). Figure 2 As shown in the figure, this method can regulate the emission color of aliphatic amine-type non-traditional fluorescent polymers by adjusting the main chain structure of the secondary amine alcohol monomer, so that the emission color of the obtained aliphatic amine-type non-traditional linear fluorescent polymer gradually changes from the blue light region to the red light region. The chemical formulas involved in the above reaction are as follows:

[0053]

[0054] Example 3

[0055] Dipropynyl acetamide (0.220 g, 1 equiv) was successively mixed and stirred with 4-ethylamino-1-butanol (0.117 g, 1 equiv), 2-methylaminoethanol (0.075 g, 1 equiv), and 3-(methylamino)-1-propanol (0.089 g, 1 equiv) at 25 °C for 6 h. After the reaction was completed, the three reaction solutions were subjected to hexane precipitation, filtration, and drying to obtain four non-traditional linear fluorescent polymers: LP-10, LP-11, and LP-12. Fluorescence spectroscopy analysis revealed a significant red shift in the maximum absorption and emission peaks of LP-10, LP-11, and LP-12 in solid-state conditions. The maximum excitation wavelengths of LP-10, LP-11, and LP-12 in solid-state were 478, 579, and 610 nm, respectively, and the maximum emission wavelengths were 532, 642, and 674 nm, respectively, corresponding to green, red, and red light emission materials (as per the attached specification). Figure 3 As shown in the figure, this method can regulate the emission color of aliphatic amine-type non-traditional fluorescent polymers by adjusting the main chain structure of the secondary amine alcohol monomer, so that the emission color of the obtained aliphatic amine-type non-traditional linear fluorescent polymer gradually changes from the blue light region to the red light region. The chemical formulas involved in the above reaction are as follows:

[0056] Example 4

[0057] Ethylene glycol dipropynate (0.222 g, 1 equiv) was successively mixed and stirred with ethanolamine (0.061 g, 1 equiv), 3-amino-1-propanol (0.075 g, 1 equiv), 4-amino-1-butanol (0.089 g, 1 equiv), and 6-amino-1-hexanol (0.0117 g, 1 equiv) at 30 °C for 12 h. After the reaction was completed, the four reaction solutions were subjected to hexane precipitation, filtration, and drying to obtain three non-traditional linear fluorescent polymers: BP-1 (m=2), BP-2 (m=3), BP-3 (m=4), and BP-4 (m=6). Fluorescence spectroscopy analysis revealed a significant red shift in the maximum absorption and emission peaks of BP-1, BP-2, BP-3, and BP-4 in solid-state conditions. The maximum excitation wavelengths of BP-1, BP-2, BP-3, and BP-4 in solid-state were 480, 462, 438, and 433 nm, respectively, and the maximum emission wavelengths were 542, 522, 498, and 480 nm, respectively, corresponding to orange, green, cyan, and blue-green light emission materials (as per the instruction manual). Figure 4 As shown in the figure, this method can regulate the emission color of aliphatic amine-type non-traditional fluorescent polymers by adjusting the main chain structure of the primary amine alcohol monomer, so that the emission color of the obtained aliphatic amine-type non-traditional linear fluorescent polymer gradually changes from the blue light region to the red light region. The chemical formulas involved in the above reaction are as follows:

[0058]

[0059] Comparative Example 1 is the same as Example 1, except that R1 in Comparative Example 1 is n-butyl. Although the electron cloud density of n-butyl is smaller than that of isopropyl, the maximum excitation wavelength of the fluorescent polymer obtained in Comparative Example 1 is 504 nm, and the maximum emission wavelength is 557 nm. The emission spectrum of the fluorescent polymer obtained in Comparative Example 1 is shown in the attached specification. Figure 6 As shown. The reaction process involved in Comparative Example 1 is as follows:

[0060]

[0061] Comparative Example 2 is the same as Example 2, except that m = 6 in Comparative Example 2. The maximum excitation wavelength of the fluorescent polymer obtained in Comparative Example 2 is 582 nm, and the maximum emission wavelength is 609 nm. The emission spectrum of the fluorescent polymer obtained in Comparative Example 2 is shown in the attached specification. Figure 7 As shown. The reaction process involved in Comparative Example 2 is as follows:

[0062]

[0063] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A method for controlling the sequential redshift of the emission wavelength of aliphatic amine-type non-traditional fluorescent polymers, characterized in that, The aliphatic amine-type non-traditional fluorescent polymers include the following general structural formulas: ； Formula 1, ； Formula 2, ； Formula 3, The above-mentioned aliphatic amine-type non-traditional fluorescent polymer is a product obtained by a room temperature click reaction between the hydroxyl group of an aliphatic primary or secondary amine alcohol and the alkynyl group of ethylene glycol dipropynate or dipropynic acid acetamide. The value of n is determined by the amount of raw materials and reaction conditions in the click reaction. In the above general structural formula, the value of m ranges from 2 to 6, where m is an integer, and R1 includes straight-chain alkyl, cycloalkyl, or aryl groups. By sequentially changing the value of m or the type of R1 substituent, the maximum absorption peak and emission peak of the above-mentioned aliphatic amine-type non-traditional fluorescent polymer are red-shifted sequentially.

2. The method for controlling the sequential redshift of the emission wavelength of aliphatic amine-type non-traditional fluorescent polymers according to claim 1, characterized in that, R1 includes one of phenyl, cyclohexyl, methyl, and ethyl.

3. The method for controlling the sequential redshift of the emission wavelength of aliphatic amine-type non-traditional fluorescent polymers according to claim 1, characterized in that, For Formula 1, when m=2 and the molar ratio of aliphatic secondary amine alcohol to ethylene glycol dipropynate is 1:1, when R1 is adjusted to phenyl, cyclohexyl, methyl, and ethyl in sequence, the maximum excitation wavelength and maximum emission wavelength of the obtained aliphatic amine-type non-traditional fluorescent polymer undergo sequential redshift.

4. The method for controlling the sequential redshift of the emission wavelength of aliphatic amine-type non-traditional fluorescent polymers according to claim 1, characterized in that, For Formula 2, when R1 is methyl and the molar ratio of aliphatic secondary amine alcohol to dipropynic acid acetamide is 1:1, when m is adjusted sequentially to m=4, 3 or 2, the maximum excitation wavelength and maximum emission wavelength of the obtained aliphatic amine type non-traditional fluorescent polymer undergo sequential redshift.

5. The method for controlling the sequential redshift of the emission wavelength of aliphatic amine-type non-traditional fluorescent polymers according to claim 1, characterized in that, For Formula 3, when the molar ratio of aliphatic primary amine alcohol to ethylene glycol dipropynate is 1:1, and m is adjusted sequentially to m=2, 3, 4 or 6, the maximum excitation wavelength and maximum emission wavelength of the obtained aliphatic amine-type non-traditional fluorescent polymer undergo sequential redshift.

6. An anti-counterfeiting label, characterized in that, The method described in any one of claims 1-5 for sequentially redshifting the emission wavelength of a fatty amine-type non-traditional fluorescent polymers utilizes the method described in any one of claims 1-5.

7. A fluorescence sensor, characterized in that, The method described in any one of claims 1-5 for sequentially redshifting the emission wavelength of a fatty amine-type non-traditional fluorescent polymers utilizes the method described in any one of claims 1-5.

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