阅读说明：本技术 一种荧光星型聚合物及其制备方法和应用 (Fluorescent star polymer and preparation method and application thereof ) 是由 宋健 李铁 于 2020-04-01 设计创作，主要内容包括：本申请提供一种荧光星型聚合物及其制备方法和应用,该聚合物的重复单元的结构式为式I或式II；所述式I的结构式如下所示：<Image he="435" wi="447" file="DDA0002435050680000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>所述式II的结构式如下所示：<Image he="468" wi="461" file="DDA0002435050680000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>式I中,R和R’均为烷基,R和所述R’中的碳原子数均为6～14；式II中,R为烷基,R的碳原子数为6～14。该聚合物是以苯[1,2-b:3,4-b’:5,6-b”]三噻吩(TTB)与芴或者咔唑为结构单元的二维聚合物网状结构,该聚合物响应速度快、选择性好、灵敏度高,可以为化学爆炸物荧光检测技术提供有利帮助,也能够应用于发光二极管、生物成像、传感器等领域。(The application provides a fluorescent star polymer and a preparation method and application thereof, wherein the structural formula of a repeating unit of the polymer is shown as a formula I or a formula II; the structural formula of the formula I is shown as follows: the structural formula of formula II is shown below: in the formula I, R and R 'are both alkyl, and the number of carbon atoms in R and R' is 6-14; in the formula II, R is alkyl, and the number of carbon atoms of R is 6-14. The polymer is benzene [1,2-b:3,4-b':5,6-b ] "]The response speed of the two-dimensional polymer network structure with the structural unit of trithiophene (TTB) and fluorene or carbazoleThe method has the advantages of high speed, good selectivity and high sensitivity, can provide favorable help for the fluorescence detection technology of chemical explosives, and can also be applied to the fields of light-emitting diodes, biological imaging, sensors and the like.)

1. A fluorescent star polymer is characterized in that the structural formula of a repeating unit of the polymer is shown as a formula I or a formula II;

the structural formula of the formula I is shown as follows:

the structural formula of formula II is shown below:

in the formula I, R and R 'are both alkyl, and the number of carbon atoms in R and R' is 6-14; in the formula II, R is alkyl, and the number of carbon atoms of R is 6-14.

2. The fluorescent star polymer of claim 1, wherein if the repeating units of the polymer are of formula I; the general formula of the polymer is formula III;

if the structural formula of the repeating unit of the polymer is formula II; the general formula of the polymer is formula IV;

the structural formula of formula III is shown below:

the structural formula of the formula IV is shown as follows:

in the formula I, n is an integer between 1 and 100; in the formula II, n is an integer between 1 and 100.

3. A method for preparing the fluorescent star polymer of any of claims 1 or 2 comprising the steps of:

benzo [1,2-b:3,4-b ':5, 6-b' ] trithiophene reacts with butyl lithium under anhydrous and oxygen-free conditions to obtain a lithiated compound;

reacting the lithium compound with trimethyl tin chloride or tributyl tin chloride to obtain di-stannyl benzo [1,2-b:3,4-b':5,6-b "] trithiophene;

using bis-stannated benzo [1,2-b:3,4-b':5,6-b "] trithiophene as a first polymerization precursor, and bromine-substituted alkylfluorene or bromine-substituted alkylcarbazole as a second polymerization precursor; adding the first polymerization precursor and the second polymerization precursor into an organic solvent under an oxygen-free condition, and mixing to obtain a mixed solution;

adding a palladium catalyst into the mixed solution, and carrying out Stille coupling reaction on the mixed solution at a set reaction temperature for a set reaction time to obtain the polymer;

wherein if the bromine-substituted alkylfluorene is used as a second polymerization precursor, the structural formula of the repeating unit of the polymer is formula I; if the bromine-substituted alkyl carbazole is used as the second polymerization precursor, the structural formula of the repeating unit of the polymer is formula II.

4. The preparation method according to claim 3, wherein the molar ratio of the benzo [1,2-b:3,4-b':5,6-b "] trithiophene, the butyl lithium and the trimethyl tin chloride or the tributyltin chloride is 1 (3-3.6): (3.4-4.2).

5. The method according to claim 3, wherein the molar ratio of the first polymerization precursor to the palladium catalyst is (10 to 20): 1.

6. the production method according to claim 3, wherein the palladium catalyst comprises palladium acetate, tetratriphenylphosphine palladium or bistriphenylphosphine palladium dichloride.

7. The method according to claim 3, wherein the organic solvent is toluene or chlorobenzene.

8. The method according to claim 3, wherein the reaction temperature is 60 to 100 ℃.

9. The method according to claim 4, wherein the predetermined reaction time is 5 to 30 minutes.

10. Use of the fluorescent star polymer of any one of claims 1-2 in fluorescence detection, bioimaging, the preparation of fluorescence detection sensors and the preparation of light emitting diodes.

Technical Field

The application relates to the technical field of fluorescence detection, in particular to a fluorescent star polymer and a preparation method and application thereof.

Background

The adverse effects of explosives on national defense safety, ecological environment and human health have attracted a great deal of attention. Thus promoting researchers' exploration and development of cost-effective, selective, portable, rapid and sensitive detection methods for detecting explosives. Among various technologies for detecting explosives, fluorescence detection methods have the advantages of high sensitivity, good selectivity, fast response speed, simple operation, strong portability, low cost and the like, and are effective sensing methods in the field of explosive detection.

Most of the explosive fluorescence detection materials generally adopted in the current field are small molecular materials. Adsorption is formed by weak van der waals interaction between the explosive and the fluorescent material, and fluorescence quenching or fluorescence enhancement is generated. Some fluorescent detection small molecular materials in the prior art can realize detection within the range of 0.1-120 mu M at present, and further improve the sensitivity of fluorescent detection, and new fluorescent detection materials need to be designed and synthesized urgently.

Disclosure of Invention

The method solves the technical problem that the sensitivity of the fluorescence detection of the explosives in the prior art needs to be further improved.

In order to solve the technical problem, the embodiment of the application discloses a fluorescent star polymer, wherein the structural formula of a repeating unit of the polymer is shown as a formula I or a formula II;

the structural formula of the formula I is shown as follows:

the structural formula of formula II is shown below:

in the formula I, R and R 'are both alkyl, and the number of carbon atoms in R and R' is 6-14; in the formula II, R is alkyl, and the number of carbon atoms of R is 6-14.

Further, if the structural formula of the repeating unit of the polymer is formula I; the general formula of the polymer is formula III;

if the structural formula of the repeating unit of the polymer is formula II; the general formula of the polymer is formula IV;

the structural formula of formula III is shown below:

the structural formula of the formula IV is shown as follows:

an integer number. In the formula I, n is an integer between 1 and 100; in the formula II, n is 1-100

The second aspect of the present application provides a method for preparing the fluorescent star-shaped polymer, which comprises the following steps:

benzo [1,2-b:3,4-b ':5, 6-b' ] trithiophene reacts with butyl lithium under anhydrous and oxygen-free conditions to obtain a lithiated compound;

reacting the lithium compound with trimethyl tin chloride or tributyl tin chloride to obtain di-stannyl benzo [1,2-b:3,4-b':5,6-b "] trithiophene;

using bis-stannated benzo [1,2-b:3,4-b':5,6-b "] trithiophene as a first polymerization precursor, and bromine-substituted alkylfluorene or bromine-substituted alkylcarbazole as a second polymerization precursor; adding the first polymerization precursor and the second polymerization precursor into an organic solvent under an oxygen-free condition, and mixing to obtain a mixed solution;

adding a palladium catalyst into the mixed solution, and carrying out Stille coupling reaction on the mixed solution at a set reaction temperature for a set reaction time to obtain the polymer;

wherein if the bromine-substituted alkylfluorene is used as a second polymerization precursor, the structural formula of the repeating unit of the polymer is formula I; if the bromine-substituted alkyl carbazole is used as the second polymerization precursor, the structural formula of the repeating unit of the polymer is formula II.

Further, the molar use ratio of the benzo [1,2-b:3,4-b':5,6-b "] trithiophene, the butyl lithium and the trimethyl tin chloride or the tributyl tin chloride is 1 (3-3.6): (3.4-4.2).

Further, the molar usage ratio of the first polymerization precursor to the palladium catalyst is (10-20): 1.

further, the palladium catalyst comprises palladium acetate, tetratriphenylphosphine palladium or bistriphenylphosphine palladium dichloride.

Further, the organic solvent is toluene or chlorobenzene.

Further, the set reaction temperature is 60-100 ℃.

Further, the set reaction time is 5-30 minutes.

The third aspect of the application provides the application of the fluorescent star polymer in fluorescence detection, biological imaging, preparation of a fluorescence detection sensor and preparation of a light-emitting diode.

By adopting the technical scheme, the application has the following beneficial effects:

the fluorescent star polymer provided by the application is a two-dimensional polymer network structure taking benzene [1,2-b:3,4-b ':5, 6-b' ] trithiophene (TTB) and fluorene or carbazole as structural units, and all luminescent units can be efficiently quenched by combining one acceptor site in a polymer molecule, namely a molecular wire effect or a one-point contact and multi-point response effect. In addition, the polymer has high response speed, good selectivity and high sensitivity, can provide favorable help for a chemical explosive fluorescence detection technology, and can also be applied to the fields of light-emitting diodes, biological imaging, sensors and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic synthesis scheme of a fluorescent star polymer according to one embodiment of the present application;

FIG. 2 is a synthetic scheme of a fluorescent star polymer P1 according to an example of the present application;

FIG. 3 is a synthetic scheme of a fluorescent star polymer P2 according to an example of the present application;

FIG. 4 is a synthetic scheme of a fluorescent star polymer P3 according to one embodiment of the present application;

FIG. 5 is a synthetic scheme of a fluorescent star polymer P5 according to one embodiment of the present application;

FIG. 6 is a synthetic scheme of a fluorescent star polymer P5 according to one embodiment of the present application;

FIG. 7 is a synthetic scheme of a fluorescent star polymer P6 according to one embodiment of the present application;

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the present application. In the description of the embodiments of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The embodiment of the application discloses a fluorescent star polymer, wherein the structural formula of a repeating unit of the polymer is shown as a formula I or a formula II;

the structural formula of the formula I is shown as follows:

the structural formula of formula II is shown below:

in the formula I, R and R 'are both alkyl, and the number of carbon atoms in R and R' is 6-14; in the formula II, R is alkyl, and the number of carbon atoms of R is 6-14. The fluorescent star polymer provided by the application can be applied to fluorescence detection, such as fluorescence detection of chemical explosives, and can also be applied to the fields of light-emitting diodes, biological imaging, fluorescence detection sensors and the like.

In the examples of the present application, if the structural formula of the repeating unit of the polymer is formula I; the general formula of the polymer is formula III;

if the structural formula of the repeating unit of the polymer is formula II; the general formula of the polymer is formula IV;

the structural formula of formula III is shown below:

the structural formula of the formula IV is shown as follows:

in the formula I, R and R 'are both alkyl, the number of carbon atoms in R and R' is 6-14, and n is an integer between 1 and 100; in the formula II, R is alkyl, the number of carbon atoms of R is 6-14, and n is an integer between 1-100.

Compared with fluorescent small molecule materials, excitons formed between the fluorescent conjugated polymer and the quencher and transferred electrons can be efficiently transferred through the polymer main chain. In addition, the polymer material is used as a long-chain organic molecule, and fluorescence quenching or fluorescence enhancement generated after the polymer material is agglomerated is more obvious than that of a small-molecule material, so that the sensitivity can be obviously improved. The fluorescent conjugated polymer with the star-shaped structure provided by the application can be used for remarkably increasing the contact area between the material and the explosive molecules, so that the sensitivity of the method is further increased. At present, the polymer is used for picric acid detection, and the test of the lowest concentration of 10nM can be realized, compared with the detection in the range of 0.1-120 MuM in the prior art, the detection is obviously improved.

As a good electron-donating sensing material, the electron-donating capability of the fluorescent conjugated polymer is enhanced through excited state delocalized pi electrons so as to be beneficial to exciton migration and increase the electrostatic interaction between the polymer and the electron-deficient nitro aromatic analyte. In addition, in the fluorescent sensor of the fluorescent conjugated polymer, the combination of one acceptor site in the conjugated polymer molecule can cause the high-efficiency quenching of all the luminescent units, namely the "molecular wire" effect or the "one-point contact, multi-point response" effect.

The fluorescent star polymer provided by the application is a two-dimensional polymer network structure taking benzene [1,2-b:3,4-b ':5, 6-b' ] trithiophene (TTB) and fluorene or carbazole as structural units, and all luminescent units can be efficiently quenched by combining one acceptor site in a polymer molecule, namely a molecular wire effect or a one-point contact and multi-point response effect. In addition, the polymer has high response speed, good selectivity and high sensitivity, can provide favorable help for a chemical explosive fluorescence detection technology, and can also be applied to the fields of light-emitting diodes, biological imaging, sensors and the like.

In a second aspect, the present application provides a method for preparing the fluorescent star polymer, which comprises the following steps:

benzo [1,2-b:3,4-b ':5, 6-b' ] trithiophene reacts with butyl lithium under anhydrous and oxygen-free conditions to obtain a lithiated compound;

reacting the lithium compound with trimethyl tin chloride or tributyl tin chloride to obtain di-stannyl benzo [1,2-b:3,4-b':5,6-b "] trithiophene;

using bis-stannated benzo [1,2-b:3,4-b':5,6-b "] trithiophene as a first polymerization precursor, and bromine-substituted alkylfluorene or bromine-substituted alkylcarbazole as a second polymerization precursor; adding the first polymerization precursor and the second polymerization precursor into an organic solvent under an oxygen-free condition, and mixing to obtain a mixed solution; adding a palladium catalyst into the mixed solution, and carrying out Stille coupling reaction (Steiller reaction) on the mixed solution at a set reaction temperature for a set reaction time to obtain the polymer;

wherein if the bromine-substituted alkylfluorene is used as a second polymerization precursor, the structural formula of the repeating unit of the polymer is formula I; if the bromine-substituted alkyl carbazole is used as the second polymerization precursor, the structural formula of the repeating unit of the polymer is formula II. The synthetic route for preparing the star polymer is shown in figure 1. In FIG. 1, R, R' is an alkyl group having 6 to 14 carbon atoms; n is an integer of 1 to 100.

In the embodiment of the application, the molar ratio of the benzo [1,2-b:3,4-b':5,6-b "] trithiophene, the butyl lithium and the trimethyl tin chloride or the tributyl tin chloride is 1 (3-3.6): (3.4-4.2).

In the embodiment of the application, the molar ratio of the first polymerization precursor to the palladium catalyst is (10-20): 1.

in the embodiment of the application, the palladium catalyst can be palladium acetate, tetratriphenylphosphine palladium, bis-triphenylphosphine palladium dichloride or the like.

In the embodiment of the present application, the organic solvent may be toluene or chlorobenzene.

In the embodiment of the application, the set reaction temperature is 60-100 ℃.

In the embodiment of the application, the set reaction time is 5-30 minutes.

The third aspect of the application provides applications of the fluorescent star-shaped polymer in biological imaging, preparation of a fluorescence detection sensor and preparation of a light-emitting diode.

The following is a description of an example of the preparation of a particular fluorescent star polymer.