CN113402622A

CN113402622A - Quinoline amino carboxymethyl cellulose fluorescent microsphere, preparation method and application thereof

Info

Publication number: CN113402622A
Application number: CN202110670323.1A
Authority: CN
Inventors: 杨益琴; 赵菲; 王忠龙; 孟志远; 王晓媛; 寇佳丽; 武杨梅; 王石发
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2021-06-17
Filing date: 2021-06-17
Publication date: 2021-09-17
Anticipated expiration: 2041-06-17
Also published as: CN113402622B

Abstract

The invention discloses a quinoline amino carboxymethyl cellulose fluorescent microsphere, a preparation method and application thereof, wherein carboxymethyl cellulose is used as a raw material and reacts with epichlorohydrin by an inverse suspension method to prepare a glycidyl ether group carboxymethyl cellulose microsphere; then 8-aminoquinoline and the epoxy group of the glycidyl ether group carboxymethyl cellulose microsphere are subjected to nucleophilic addition reaction to prepare the quinoline amino carboxymethyl cellulose microsphere. The quinoline amino carboxylic acid methyl synthesized by the inventionThe cellulose microsphere emits orange fluorescence under ultraviolet irradiation, has good luminous performance, and is added with Cu²⁺After ionization, Cu can be specifically identified²⁺Ions, so that the original orange fluorescence is rapidly quenched; and quinoline amino carboxymethyl cellulose fluorescent microsphere pair Cu²⁺The ions have strong adsorption capacity and can rapidly remove Cu in the solution²⁺Ions.

Description

Quinoline amino carboxymethyl cellulose fluorescent microsphere, preparation method and application thereof

Technical Field

The invention belongs to the technical field of fluorescence detection, and particularly relates to a quinoline amino carboxymethyl cellulose fluorescent microsphere, a preparation method and application thereof.

Background

Carboxymethyl cellulose (CMC) is an important cellulose derivative, contains abundant hydroxyl and carboxyl in a molecular structure, and different functional groups can be bonded to a carboxymethyl cellulose chain through chemical modification so as to endow the carboxymethyl cellulose with more application properties.

Excessive Cu in the human body²⁺Ions cause liver cirrhosis, diarrhea, vomiting, etc., resulting in various diseases such as Alzheimer's disease, Wilson's disease, etc. In a water body, excessive copper can pollute the water body, stress harm can be caused to aquatic animals and plants, and growth of the aquatic animals and plants is influenced. Conventional detection of Cu²⁺The methods mainly comprise an electrochemical method, a voltammetry method, an atomic absorption spectrometry method, an inductively coupled plasma mass spectrometry method, a spectrophotometry method and the like, but the methods have the defects of expensive equipment, long detection time, incapability of real-time monitoring and the like. Compared with the traditional detection method, the fluorescent probe detection method has the advantages of simplicity, rapidness, sensitivity and the like. Removal of Cu²⁺The common techniques of the ions mainly comprise an ion exchange method, a chemical precipitation method, a photocatalysis method, an adsorption method, membrane filtration and the like, wherein the adsorption method has the characteristics of rapidness, simple and convenient operation, low energy consumption, no secondary pollution and the like. However, neither has been foundCan detect and efficiently adsorb Cu²⁺The bifunctional material of (1).

Therefore, the method is designed and developed to not only detect but also effectively adsorb Cu²⁺The bifunctional material has important significance.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made keeping in mind the above and/or other problems occurring in the prior art.

One of the purposes of the invention is to provide a quinoline amino carboxymethyl cellulose fluorescent microsphere, the synthesized quinoline amino carboxymethyl cellulose microsphere emits orange fluorescence under ultraviolet irradiation, the luminescent property is good, and Cu is added²⁺After ionization, Cu can be specifically identified²⁺Ions, so that the original orange fluorescence is rapidly quenched; and quinoline amino carboxymethyl cellulose fluorescent microsphere pair Cu²⁺The ions have strong adsorption capacity and can rapidly remove Cu in the solution²⁺Ions.

In order to solve the technical problems, the invention provides the following technical scheme: a quinoline amino carboxymethyl cellulose fluorescent microsphere has a structural formula as follows:

another object of the present invention is to provide a method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres, which comprises,

carboxymethyl cellulose (CMC) is used as a raw material and reacts with Epichlorohydrin (ECH) by an inverse suspension method to prepare glycidyl ether group carboxymethyl cellulose microspheres (CMC-GE);

and (2) carrying out nucleophilic ring-opening reaction on the glycidyl ether group carboxymethyl cellulose microsphere and 8-Aminoquinoline (AQ) to prepare the quinoline amino carboxymethyl cellulose fluorescent microsphere (CMC-GE-AQ).

As a preferred scheme of the preparation method of the quinoline amino carboxymethyl cellulose fluorescent microsphere, the preparation method comprises the following steps: performing nucleophilic ring-opening reaction, adding the glycidyl ether group carboxymethyl cellulose microsphere into water, and adjusting the pH value of a reaction system; slowly adding 8-aminoquinoline tetrahydrofuran solution for reaction, filtering the reaction mixture, washing a filter cake with ethanol to remove residual 8-aminoquinoline, and washing until the filtrate is free of fluorescence to obtain the quinoline amino carboxymethyl cellulose fluorescent microsphere.

As a preferred scheme of the preparation method of the quinoline amino carboxymethyl cellulose fluorescent microsphere, the preparation method comprises the following steps: the addition amount of the 8-aminoquinoline tetrahydrofuran solution is 7-82 mmol/g.

As a preferred scheme of the preparation method of the quinoline amino carboxymethyl cellulose fluorescent microsphere, the preparation method comprises the following steps: in the 8-aminoquinoline tetrahydrofuran solution, 0.05-0.70 g of 8-aminoquinoline is dissolved in 2-10 mL of tetrahydrofuran.

As a preferred scheme of the preparation method of the quinoline amino carboxymethyl cellulose fluorescent microsphere, the preparation method comprises the following steps: and adjusting the pH value of the reaction system to 11-14.

As a preferred scheme of the preparation method of the quinoline amino carboxymethyl cellulose fluorescent microsphere, the preparation method comprises the following steps: and slowly adding 8-aminoquinoline tetrahydrofuran solution for reaction, and reacting for 4-8 h at 65 ℃.

Another object of the present invention is to provide the quinoline amino carboxymethyl cellulose fluorescent microsphere as described above for detecting and adsorbing Cu²⁺The application of ion dual-function material.

Compared with the prior art, the invention has the following beneficial effects:

the invention relates to a quinoline amino carboxymethyl cellulose fluorescent microsphere prepared by taking carboxymethyl cellulose which is a derivative of natural renewable resource cellulose as a matrix, and the preparation method is used for treating Cu²⁺The ions have strong adsorption capacity and can rapidly remove Cu in the solution²⁺Ion(s)Is a method for simultaneously detecting and removing Cu²⁺The ionic dual-function material has good application prospect.

Drawings

In order to more clearly illustrate the technical solutions of 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 inventive exercise. Wherein:

FIG. 1 is an infrared spectrum of CMC-GE-AQ, CMC-GE, CMC and AQ in example 1 of the present invention;

FIG. 2 is a graph showing fluorescence spectra of CMC-GE-AQ, CMC-GE, CMC and AQ in example 1 of the present invention;

FIG. 3 is a graph showing fluorescence spectra and fluorescence photographs of CMC-GE-AQ suspensions in accordance with different AQ addition amounts in example 2 of the present invention;

FIG. 4 is a graph showing fluorescence spectra and fluorescence photographs of CMC-GE-AQ in various solvents in example 3 of the present invention;

FIG. 5 shows the results of the fluorescent responses of CMC-GE-AQ to different metal ions in example 4 of the present invention;

FIG. 6 shows Cu variants in example 5 of the present invention²⁺The fluorescence intensity of CMC-GE-AQ at concentration;

FIG. 7 is a graph of CMC-GE and CMC-GE-AQ versus Cu at different initial concentrations for example 6 of the present invention²⁺The adsorption properties of the ions;

FIG. 8 shows the Cu adsorption by CMC-GE and CMC-GE-AQ in example 7 of the present invention²⁺Front and rear images.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, specific embodiments thereof are described in detail below with reference to examples of the specification.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Example 1

Synthesis and characterization of quinoline amino carboxymethyl cellulose fluorescent microsphere (CMC-GE-AQ)

The preparation method of the quinoline amino carboxymethyl cellulose microsphere comprises the following reaction formula:

the method comprises the following specific steps:

(1) preparation of glycidyl ether-based carboxymethyl cellulose microspheres

Mixing 240mL of liquid paraffin, 0.95g of span 80 and 3.3mL of C₄H₉OH and 3.3mL CCl₄Adding into a 500mL three-neck flask equipped with a thermometer, a condenser and a stirrer, stirring at 60 deg.C, and slowly adding into a prepared carboxymethyl cellulose NaOH solution (3g carboxymethyl cellulose dissolved in 60mL NaOH solution with pH of 14); then 12mL of epichlorohydrin is added dropwise and the reaction is carried out for 3 h. And filtering the reaction mixture, washing a filter cake by using ethanol to remove excessive epichlorohydrin, and washing the filter cake to be neutral by using distilled water to obtain the glycidyl ether-based carboxymethyl cellulose microsphere (CMC-GE).

(2) Preparation of quinoline amino carboxymethyl cellulose fluorescent microsphere

Adding 26.6g of glycidyl ether group carboxymethyl cellulose microspheres into 75mL of water, and adjusting the pH value of a reaction system to 12 by using a 30% NaOH solution; slowly adding a prepared 8-aminoquinoline tetrahydrofuran solution (0.47g of 8-aminoquinoline is dissolved in 4mL of tetrahydrofuran), reacting at 65 ℃ for 6h, filtering the reaction mixture, washing a filter cake with ethanol to remove residual 8-aminoquinoline, and washing until the filtrate is free of fluorescence to obtain the quinoline amino carboxymethyl cellulose fluorescent microspheres (CMC-GE-AQ).

And (3) analyzing the characteristics of the CMC, the AQ, the CMC-GE and the CMC-GE-AQ. An infrared spectrometer (VERTEX80V, Bruker) is arranged at 4000-650 cm^-1Structural analysis of the sample was recorded over the scan range. The resolution of 32 scans was 4cm^-1. FT-IR spectra of CMC-GE-AQ, CMC-GE, CMC and AQ, as shown in FIG. 1. The FT-IR spectrum of AQ showed 3450cm^-1And 3350cm^-1The absorption band at (b) is primary amine stretching. On the other hand, the CMC is 1000-1300 cm^-1Bands in the range are caused by C-C and C-O vibrations in alcohols, ethers and esters. The CMC-GE-AQ, CMC-GE and CMC samples were at 3430cm^-1And 2925cm^-1There are absorption bands. The former is the band where the O-H stretching vibration is located, and the latter is-CH₂-a belt on which the stretching vibrations are located. CMC-GE at 1113cm^-1A new band appears, which is the stretching vibration of the epoxy group. After AQ is functionalized, the spectrum of CMC-GE-AQ is obviously changed. At 1384cm^-1(tensile vibration of C-N) and 1725cm^-1Two new bands appeared (C ═ N tensile vibration). The spectroscopic data strongly suggest the successful introduction of AQ on CMC-GE.

Respectively uniformly dispersing quinoline amino carboxymethyl cellulose fluorescent microspheres, glycidyl ether group carboxymethyl cellulose microspheres, carboxymethyl cellulose and 8-aminoquinoline in DMF + H₂The fluorescence emission spectra of these four samples were measured in a mixed solvent of O (DMF: water ═ 8:2, v/v), and the results are shown in fig. 2. The result shows that the fluorescence intensity of the quinoline fluorescent carboxymethyl cellulose microsphere is twice as high as that of 8-aminoquinoline, and the glycidyl ether group carboxymethyl cellulose microsphere does not have fluorescence.

Example 2

Influence of AQ introduction amount on CMC-GE-AQ fluorescence intensity

This example CMC-GE-AQ was prepared in the same manner as example 1 except that AQ was added in amounts of 7mmol/g, 22mmol/g, 37mmol/g, 52mmol/g, 67mmol/g and 82mmol/g, respectively, and named CMC-GE-AQ₁、CMC-GE-AQ₂、CMC-GE-AQ₃、CMC-GE-AQ₄、CMC-GE-AQ₅ and CMC-GE-AQ₆。

Respectively adding CMC-GE-AQ₁、CMC-GE-AQ₂、CMC-GE-AQ₃、CMC-GE-AQ₄、CMC-GE-AQ₅ and CMC-GE-AQ₆Uniformly dispersed in DMF + H₂Fluorescence emission spectra of the six samples were measured in a mixed solvent of O (DMF: water ═ 8:2, v/v) and compared with that of CMC-GE in example 1, and the results are shown in fig. 3.

The result shows that the CMC-GE suspension is not fluorescent, and the CMC-GE-AQ is added with the increasing of the introduction amount of the AQ₁、CMC-GE-AQ₂、CMC-GE-AQ₃And CMC-GE-AQ₄Gradually increases in fluorescence intensity. Wherein the CMC-GE-AQ₅The suspension had good fluorescence intensity. When the introduced amount of AQ is more than 67mmol/g, CMC-GE-AQ₆The fluorescence intensity of (2) is drastically decreased. This phenomenon is consistent with the consequences of energy dissipation. The energy that the molecules acquire from the excitation source is fixed and collisions between fluorescent small molecules compete with the fluorescent pathway. However, the increase of the concentration of the small molecules increases the collision probability of the fluorescent small molecules, resulting in energy dissipation, thereby greatly reducing the luminous efficiency of the fluorescence. Thus, CMC-GE-AQ₅The microspheres with the most suitable amount of AQ were introduced and selected for further study.

Example 3

Effect of solvent on CMC-GE-AQ fluorescence intensity

CMC-GE-AQ prepared in example 1 was uniformly dispersed in DMF + H₂In a mixed solvent of O, DMF/H₂The volume ratios of O were 8:2, 7:3, 6:4 and 5:5, respectively, and fluorescence emission spectra of these four samples were measured, and the results are shown in FIG. 4. The fluorescence intensity of CMC-GE-AQ at the emission peak gradually increased with the increase of the DMF to water volume ratio. When DMF/H₂The fluorescence emission reached a maximum at a volume ratio of O of 8: 2. The trend of increase is consistent with a decrease in the average dielectric constant.

Example 4

Fluorescent response of CMC-GE-AQ to different metal ions

The CMC-GE-AQ prepared in example 1 was uniformly dispersed in DMF+H₂In O mixed solvent (DMF: H)₂O8: 2, v/v) were made into suspensions, 10 was added separately^-4mol L^-1Metal ion Pb of²⁺、Cu²⁺、Ag⁺、Hg²⁺、Zn²⁺、Cd²⁺、Mg²⁺、Al³⁺、Cs⁺And Mn²⁺The fluorescence intensity of the suspension was then measured and 10 more samples were added for each sample^-4mol L^-1Cu of (2)²⁺The fluorescence intensity of the suspension after ionization was measured, and the results are shown in FIG. 5, in which (a) is the fluorescence spectrum of CMC-GE-AQ suspension of different metal ions, and (b) is the fluorescence spectrum of other metal ions and Cu²⁺Fluorescence intensity of CMC-GE-AQ suspension in coexistence. Most of all metal ions tested had no significant effect on the fluorescence phenomenon of CMC-GE-AQ, only Cu²⁺The quenching effect of the ions on the quinoline amino carboxymethyl cellulose fluorescent microsphere is obvious, so that the fluorescence is quenched. Researching the interference of CMC-GE-AQ fluorescence detection capability and recording other metal ions and Cu²⁺Maximum fluorescence value of CMC-GE-AQ in coexistence. As can be seen from FIG. 5, other metal ions coexist to add Cu²⁺The interference of the CMC-GE-AQ fluorescence response is small or slight. Proving CMC-GE-AQ vs Cu²⁺Has good selectivity and interference resistance.

Example 5

Different Cu²⁺Fluorescent intensity of CMC-GE-AQ at concentration

CMC-GE-AQ complex suspensions prepared in example 1 (DMF: water ═ 8:2) were taken and Cu was added at various concentrations²⁺The fluorescence emission spectrum of the suspension after ionization was measured and the results are shown in FIG. 6, in which (a) is different Cu²⁺The fluorescence spectrum of the CMC-GE-AQ suspension at the concentration (b) is the maximum fluorescence intensity and the corresponding Cu²⁺Linear fit of concentration. At 10^-6～7×10^-5In the mol/L concentration range, with Cu²⁺The maximum fluorescence intensity of CMC-GE-AQ is rapidly reduced when the ion concentration is increased, when Cu is added²⁺Ion concentration higher than 10^-5At mol/L, the rate of descent becomes slower or even flatter. At 10^-6～7×10^-5maximum fluorescence intensity in the mol/L range with corresponding Cu²⁺The concentrations were fitted linearly. Calculated values for R2 of greater than 0.99 indicate that the maximum fluorescence intensity corresponds to Cu over a wide range of concentrations²⁺The concentration has a good linear relationship. Method for measuring CMC-GE-AQ to Cu by adopting fluorescence titration method²⁺The detection sensitivity of (3). The results show that CMC-GE-AQ is on Cu²⁺The fluorescence detection of the ions has good sensitivity, and the detection limit is 7 multiplied by 10^-8M。

Example 6

CMC-GE-AQ vs Cu²⁺Adsorption capacity of

Weighing 10mg of CMC-GE and CMC-GE-AQ, and adding 50mL of Cu with initial concentration of 20-260 mg/L²⁺Adsorbing the ionic solution at 30 deg.C for 4h, and calculating CMC-GE and CMC-GE-AQ to Cu according to the concentration change of copper ion solution before and after adsorption measured by atomic spectrophotometer²⁺The results of the adsorption amount of the ions are shown in FIG. 7. The two microspheres have similar adsorption performance and the adsorption quantity is dependent on Cu²⁺The initial concentration increases. Most notably, the adsorption capacity of CMC-GE-AQ was greater than that of CMC-GE over the entire concentration range. This illustrates the CMC-GE-AQ vs Cu²⁺Has good adsorption capacity. The maximum adsorption capacity reaches 493.26mg/g, and the quinoline amino carboxymethyl cellulose fluorescent microsphere is Cu²⁺The ions have strong adsorption capacity.

Example 7

Comparing CMC-GE and CMC-GE-AQ for Cu adsorption²⁺The adsorption conditions of the CMC-GE-AQ to Cu under sunlight and ultraviolet lamps²⁺The visual response process of adsorption is shown in fig. 8; wherein (a) is the adsorption of Cu by CMC-GE and CMC-GE-AQ²⁺The adsorption conditions of the front and the back under sunlight are (b) CMC-GE and CMC-GE-AQ are used for adsorbing Cu²⁺Front and back under the ultraviolet lamp. First, CMC-GE and CMC-GE-AQ were uniformly dispersed in the solution. Meanwhile, it is transparent in the sun and emits bright orange fluorescence under 365 nm ultraviolet light. While adding Cu to the suspension²⁺After that, the microspheres become small and dark rapidly, and the fluorescence is quenched obviously. The CMC-GE-AQ can be used as a fluorescent probe with quick response.

Cu adsorption by CMC-GE and CMC-GE-AQ²⁺SEM images before and after are shown in FIG. 8, in which (c) is CMC-GE adsorbing Cu²⁺The former SEM image (d) is that CMC-GE-AQ adsorbs Cu²⁺SEM image of front stage, (e) CMC-GE adsorbing Cu²⁺The SEM image after (f) is that CMC-GE-AQ adsorbs Cu²⁺SEM image after. As can be seen from FIG. 8(c), the dried CMC-GE microspheres had petal-shaped macropores, whereas the CMC-GE-AQ microspheres were more dense, FIG. 8 (d). As is apparent from FIGS. 8(e) and (f), two kinds of microspheres adsorbed Cu²⁺The rear part is smaller, and the surface is smoother. Two kinds of microspheres are due to Cu²⁺The contraction is obvious by the interaction with the anion carboxyl in the CMC-GE-AQ network, the surface is relatively compact, and the fundamental reason is the reduction of electrostatic repulsion. The result shows that the CMC-GE-AQ detects Cu²⁺Has high sensitivity and specificity.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. A quinoline amino carboxymethyl cellulose fluorescent microsphere is characterized in that: the structural formula is as follows:

2. the method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 1, wherein the method comprises the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

carboxymethyl cellulose is used as a raw material, and reacts with epichlorohydrin by an inverse suspension method to prepare glycidyl ether-based carboxymethyl cellulose microspheres;

and carrying out nucleophilic ring-opening reaction on the glycidyl ether group carboxymethyl cellulose microsphere and 8-aminoquinoline to prepare the quinoline amino carboxymethyl cellulose fluorescent microsphere.

3. The method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 2, wherein the method comprises the following steps: performing nucleophilic ring-opening reaction, adding the glycidyl ether group carboxymethyl cellulose microsphere into water, and adjusting the pH value of a reaction system; slowly adding 8-aminoquinoline tetrahydrofuran solution for reaction, filtering the reaction mixture, washing a filter cake with ethanol to remove residual 8-aminoquinoline, and washing until the filtrate is free of fluorescence to obtain the quinoline amino carboxymethyl cellulose fluorescent microsphere.

4. The method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 3, wherein the method comprises the following steps: the addition amount of the 8-aminoquinoline tetrahydrofuran solution is 7-82 mmol/g.

5. The method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 3 or 4, wherein the method comprises the following steps: in the 8-aminoquinoline tetrahydrofuran solution, 0.05-0.70 g of 8-aminoquinoline is dissolved in 2-10 mL of tetrahydrofuran.

6. The method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 3 or 4, wherein the method comprises the following steps: and adjusting the pH value of the reaction system to 11-14.

7. The method for preparing quinoline amino carboxymethyl cellulose fluorescent microspheres according to claim 3 or 4, wherein the method comprises the following steps: and slowly adding 8-aminoquinoline tetrahydrofuran solution for reaction, and reacting for 4-8 h at 65 ℃.

8. The quinoline amino carboxymethyl cellulose fluorescent microsphere as claimed in claim 1 for detecting and adsorbing Cu²⁺The application of ion dual-function material.