CN103992789B - A kind of preparation method of inorganic-organic hybrid fluorescent microsphere - Google Patents

Abstract

The preparation method of a kind of inorganic-organic hybrid fluorescent microsphere of the present invention, belongs to fluorescent material preparing technical field.This its method has been synthesized with acrylamide (AM) for monomer for utilizing precipitation polymerization method, allyl group fluorescein is linking agent as fluorescence dye, Vinylstyrene (DVB), 2,2 ˊ-azo two is butyronitrile (AIBN) inorganic-organic hybrid fluorescent microsphere (SiO that is initiator ₂mPSPoly (AM-co-DVB)).The SiO of preparation ₂it is narrow that MPSPoly (AM-co-EGDMA) microballoon has particle size distribution range, and synthesis is simple, good dispersity, the features such as fluorescent emission is strong.

Description

A kind of preparation method of inorganic-organic composite fluorescent microsphere

technical field

The invention relates to a method for preparing inorganic-organic composite fluorescent microspheres, which belongs to the technical field of fluorescent material preparation.

Background technique

Fluorescent microspheres, as a special functional microsphere, are more and more popular among scientific researchers for their stable morphological structure and stable and efficient luminous efficiency. The newly developed fluorescent microspheres have uniform particle size, good monodispersity, good stability and high luminous efficiency. Fluorescent microspheres generally refer to microspheres marked with fluorescent substances (including surface coating) on the surface of the microspheres or microspheres containing fluorescent substances (such as embedding or aggregation) in the internal structure of the microspheres, which can excite fluorescence when stimulated by external energy. It is a functional microsphere loaded with fluorescent molecules, and its shape can be any shape, generally spherical. In recent years, with the in-depth study of fluorescent probe technology, people have been able to prepare a variety of fluorescent microspheres with particle sizes ranging from nanometer to submicron. Fluorescent microspheres have a relatively stable morphological structure and luminescent behavior, and are much less affected by external conditions such as solvents, heat, electricity, and magnetism than pure fluorescent compounds. However, due to their complex preparation process, weak fluorescence, easy aggregation and background Fluorescence limitations, etc., have severely limited the application fields of fluorescent microspheres. Therefore, it is particularly important to overcome these problems with reasonable structural design and process design.

Fluorescent microspheres refer to particles with a diameter ranging from nanometers to tens of microns, loaded with fluorescent substances on the surface or inside, and capable of emitting fluorescence when stimulated by external conditions. The shape of fluorescent microspheres is mostly spherical, but there are also other shapes. The carrier of fluorescent microspheres can be polymer or inorganic material. According to the difference of carrier and fluorescent substance, it is generally divided into two categories: inorganic/organic fluorescent microspheres and organic/organic fluorescent microspheres. Commonly used fluorescent dyes, such as rhodamine, fluorescein, and Nile red dye, are often used to prepare fluorescent spheres. Rhodamine and fluorescein dyes have excellent biocompatibility, high quantum yield and large extinction coefficient; Nile red dye is often used as an environment-sensitive fluorescent probe to detect biomolecules. In addition, micron-scale materials have large surface area and good dispersion and are often used in the fields of biomedicine and colloid science.

In summary, the inorganic-organic composite fluorescent microspheres of the present invention have the characteristics of narrow particle size distribution range, simple synthesis, good dispersibility, and strong fluorescence emission.

Contents of the invention

Acrylamide (AM) was synthesized by precipitation polymerization, allyl fluorescein was used as fluorescent reagent, divinylbenzene (DVB) was used as crosslinking agent, 2,2'-azobisisobutyronitrile (AIBN) Organic-inorganic composite SiO ₂ Poly(AM-co-DVB) fluorescent microspheres as initiator. The prepared SiO ₂ Poly(AM-co-DVB) fluorescent microspheres have strong green fluorescence and thin fluorescent shell.

The technical scheme adopted in the present invention is:

A preparation method of inorganic-organic composite fluorescent microspheres is carried out according to the following steps:

(1) Preparation of SiO ₂ MPS nanospheres:

_SiO2 nanospheres were prepared by hydrolysis method. Ammonia water was added to ethanol and distilled water (1:1, v/v), ultrasonicated for 15 minutes, and magnetically stirred. Measure tetraethyl orthosilicate (TEOS) and slowly drop it into the above solution. After the dropwise addition, react at room temperature for 24 hours. Measure 3-methacryloyloxypropyltrimethoxysilane (MPS) and slowly add it dropwise into the resulting milky white dispersion, and continue to stir for 24 hours. After the reaction, the SiO ₂ nanospheres were collected by a high-speed centrifuge and dried in a vacuum oven for 12 h.

2. Preparation of SiO ₂ MPSPoly (AM-co-DVB) microspheres:

Ultrasonic disperse SiO ₂ MPS nanospheres in acetonitrile, then add 2~4mmol acrylamide (AM), 0.036~0.072g allyl fluorescein and 0.1~1.0mL cross-linking agent divinylbenzene (DVB); mix After uniformity, add 2.5% initiator azobisisobutyronitrile (AIBN) based on the total amount of monomers. Air was purged by bubbling nitrogen gas for 15 minutes, and sealed under nitrogen atmosphere. Using heat-initiated polymerization, place it in a 60°C constant temperature oil bath and heat for 24 hours. After the polymerization is completed, a yellow crude product is obtained. Soak and wash with ethanol until the washing liquid is colorless, and use a fluorescence spectrometer to detect that there is no luminescent substance remaining in the washing liquid.

In step (1), add 2.0mL of ammonia water to every 50mL of ethanol and distilled water (1:1, v/v), measure 2.0mL of tetraethyl orthosilicate (TEOS), and finally add 1mL of 3-methacryloyloxy Propyltrimethoxysilane (MPS).

In step (2), 250 mg of SiO ₂ MPS nanospheres were ultrasonically dispersed in 60 mL of acetonitrile, and 2-4 mmol AM, 0.036-0.072 g of allyl fluorescein and 0.1-1.0 mL of cross-linking agent DVB were added to each 60 mL of acetonitrile.

The technical advantage of the present invention is that vinyl-modified fluorescein is used as a fluorescent dye to co-polymerize with monomers and cross-linking, so that allyl fluorescein is uniformly dispersed in the microsphere shell, and the microspheres emit light evenly; prepared by precipitation polymerization Fluorescent microspheres with narrow particle size distribution.

Description of drawings

Fig. 1 Transmission electron microscope (TEM) of SiO ₂ MPSPoly(AM-co-DVB) microspheres. It can be seen from the figure that the diameter of the microsphere is about 0.27 μm, the thickness of the shell layer is about 5 nm, the particle size is uniform, and the dispersion is good.

Fig. 2 Scanning electron microscope (SEM) of SiO ₂ MPSPoly(AM-co-DVB) microspheres. It can be seen from the figure that the microspheres have a good spherical shape, and the particle size is relatively uniform, with a diameter of about 270nm.

Fig. 3 Fluorescence spectrum of SiO ₂ MPSPoly(AM-co-DVB). It can be seen from the figure that the fluorescence emission peak of the microsphere is 521nm.

detailed description

The present invention will be further described below in conjunction with specific implementation examples, but the present invention is not limited to these examples.

Example 1

Ultrasonic disperse 250mg SiO ₂ MPS nanospheres in 60mL of acetonitrile, add 2mmol of AM, 0.036g of allyl fluorescein and 0.1mL of DVB to each 60mL of acetonitrile; add 2.5% of the total amount of monomer azo after mixing evenly Diisobutyronitrile (AIBN). Air was purged by bubbling nitrogen gas for 15 minutes, and sealed under nitrogen atmosphere. Using heat-initiated polymerization, place it in a 60°C constant temperature oil bath and heat for 24 hours. After the polymerization is completed, a yellow crude product is obtained. Soak and wash with ethanol until the washing liquid is colorless, and use a fluorescence spectrometer to detect that there is no luminescent substance remaining in the washing liquid.

Example 2

Ultrasonic disperse 250mg SiO2MPS nanospheres in every 60mL acetonitrile, add 4mmolAM, 0.072g allyl fluorescein and 1.0mLDVB to every 60mL acetonitrile; add 2.5% initiator azobisisobutyronitrile after mixing evenly (AIBN). Air was purged by bubbling nitrogen gas for 15 minutes, and sealed under nitrogen atmosphere. Using heat-initiated polymerization, place it in a 60°C constant temperature oil bath and heat for 24 hours. After the polymerization is completed, a yellow crude product is obtained. Soak and wash with ethanol until the washing liquid is colorless, and use a fluorescence spectrometer to detect that there is no luminescent substance remaining in the washing liquid. .

Example 3

Ultrasonic disperse 250mg SiO2MPS nanospheres in every 60mL acetonitrile, add 3mmolAM, 0.054g allyl fluorescein and 0.5mLDVB to every 60mL acetonitrile; add 2.5% initiator azobisisobutyronitrile after mixing evenly (AIBN). Air was purged by bubbling nitrogen gas for 15 minutes, and sealed under nitrogen atmosphere. Using heat-initiated polymerization, place it in a 60°C constant temperature oil bath and heat for 24 hours. After the polymerization is completed, a yellow crude product is obtained. Soak and wash with ethanol until the washing liquid is colorless, and use a fluorescence spectrometer to detect that there is no luminescent substance remaining in the washing liquid. TEM, SEM and fluorescence emission spectra are shown in Figure 1, Figure 2 and Figure 3, respectively.

Claims (1)

1. a preparation method for inorganic-organic hybrid fluorescent microsphere, is characterized in that carrying out according to following step:

(1) SiO ₂the preparation of MPS nanometer ball:

Hydrolysis method is adopted to prepare SiO ₂nanometer ball: ethanol and distilled water by volume 1:1 add ammoniacal liquor, ultrasonic 15 minutes, magnetic agitation;

Measuring tetraethyl orthosilicate TEOS slowly instills in above-mentioned solution, after dropwising, react 24 hours under room temperature condition, measuring 3-methacryloxypropyl trimethoxy silane MPS is slowly added drop-wise in the oyster white dispersion liquid of generation, continue stirring 24 hours, after reaction terminates, supercentrifuge is utilized to collect SiO ₂nanometer ball, dry 12h in vacuum drying oven;

(2) SiO ₂the preparation of MPSPoly (AM-co-DVB) microballoon:

By SiO ₂mPS nanometer ball ultrasonic disperse is in acetonitrile, then acrylamide AM, 0.036 ~ 0.072g allyl group fluorescein and 0.1 ~ 1.0mL cross-linker divinylbenzene DVB is added respectively, the initiator Diisopropyl azodicarboxylate AIBN of 2.5% of the total amount of substance of monomer is added after mixing, pass into nitrogen 15 minutes excluding airs, seal under nitrogen atmosphere, adopt thermal-initiated polymerization mode, be placed in 60 DEG C of thermostatical oil baths and heat 24 hours, after being polymerized, obtain yellow thick product; Colourless to washing lotion with alcohol immersion washing, use spectrofluorometer to detect washing lotion and retain without luminophore;

Wherein add 2.0mL ammoniacal liquor in every 50mL ethanol and distilled water in step (1), measure the tetraethyl orthosilicate TEOS of 2.0mL, finally add 1mL3-methacryloxypropyl trimethoxy silane MPS;

Wherein ultrasonic disperse 250mgSiO in every 60mL acetonitrile in step (2) ₂mPS nanometer ball, every 60mL acetonitrile adds 2 ~ 4mmolAM, 0.036 ~ 0.072g allyl group fluorescein and 0.1 ~ 1.0mL linking agent DVB respectively.