CN105328203B - 1 H, 1,2,4 triazoles, 3 mercaptan bovine serum albumin(BSA) fluorescent au nanocluster material and preparation method thereof - Google Patents

Abstract

The invention discloses a 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nano-cluster fluorescent material and a preparation method thereof. Chlorauric acid, 1-H-1 , 2,4‑triazole‑3‑thiol and bovine serum albumin were used as raw materials to synthesize water-soluble gold nanocluster fluorescent materials in one step. The invention is a preparation method of a novel gold nano-cluster fluorescent material, which has the advantages of rapid preparation, simplicity, environmental protection and the like. The synthesized 1‑H‑1,2,4‑triazole‑3‑thiol‑bovine serum albumin‑gold nanoclusters exhibit strong rose-red fluorescence (the maximum emission wavelength is 650 nm), Stoke It has the advantages of large Stein shift (245 nm), good water solubility and high stability.

Description

1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster fluorescence Materials and their preparation methods

technical field

The invention relates to a preparation method of 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nano-cluster fluorescent material, which belongs to the field of nanotechnology.

Background technique

In recent years, the application of fluorescent nanomaterials as fluorescent markers in biology has attracted much attention. So far, researchers have developed many different types of fluorescent nanomaterials such as semiconductor quantum dots, dye-doped nanoparticles, and carbon nanodots. As a new class of fluorescent nanomaterials, fluorescent gold nanoclusters (AuNCs) have the advantages of good photophysical properties, large specific surface area, easy surface modification, and adjustable fluorescence properties. Gold nanoclusters are stable aggregates composed of several to dozens of gold atoms, usually less than 2 nm in diameter, between single atoms and nanoparticles or bulky metals. Due to its size close to the Fermi wavelength of electrons, the continuous energy state property splits into discrete energy states, and molecular-like size-dependent effects appear. It has broad application prospects in the fields of compound detection, biosensing and imaging, optoelectronics and nanomedicine.

The preparation techniques of gold nanocluster fluorescent materials mainly include chemical reduction method, inverse microemulsion method, template synthesis method, monomolecular layer protection technology and ligand etching method. Among them, the monolayer protection technology is a simple and gentle cluster synthesis method. Small molecules containing certain functional groups are used as protective groups to form a protective layer on the cluster surface, thereby stabilizing gold nanoclusters and making them difficult to agglomerate. In recent decades, researchers at home and abroad have proposed a variety of different methods to prepare gold nanoclusters with high fluorescence quantum yield, good water solubility and tunable emission color.

The invention uses chloroauric acid, 1-H-1,2,4-triazole-3-thiol and bovine serum albumin as raw materials to synthesize the water-soluble gold nano-cluster fluorescent material in one step. Bovine serum albumin was used as a stabilizer, and 1-H-1,2,4-triazole-3-thiol was used as a reducing agent and modifier to control the formation of gold nanoclusters. The prepared 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster has strong rose-red fluorescence, large Stokes shift and good water solubility.

Contents of the invention

The object of the present invention is to provide a kind of 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nano-cluster fluorescent material and its 1-H-1,2,4 - Triazole-3-thiol is a reducing agent and a modifier, and bovine serum albumin is used as a stabilizer to synthesize a gold nano-cluster fluorescent material in one step.

In order to achieve the above object, the present invention adopts the following technical solutions: the preparation method of 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster fluorescent material of the present invention , which is characterized in that it is made by the following steps: mixing bovine serum albumin solution and chloroauric acid solution evenly, then adding 1-H-1,2,4-triazole-3-thiol solution, shaking and mixing , react for a certain period of time to obtain 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanoclusters, gold nanoclusters can be obtained after freeze-drying the aqueous solution of the fluorescent material of the gold nanoclusters Fluorescent material powder.

The preparation method of the described 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster fluorescent material is characterized in that bovine serum albumin is used as a stabilizer, 1 -H-1,2,4-triazole-3-thiol was used as reducing agent and modifier to control the formation of gold nanoclusters.

The volume ratio of the chloroauric acid solution, bovine serum albumin solution and 1-H-1,2,4-triazole-3-thiol solution is 5:3:2.

The concentration of the chloroauric acid solution used can be 1～100 mmol/L, the most preferred concentration is 10 mmol/L, the bovine serum albumin solution can be 5～500 mg/mL, the most preferred concentration is 50 mg/mL, 1 The concentration of -H-1,2,4-triazole-3-thiol solution can be 0.01~1 mol/L, the most preferred concentration is 0.1 mol/L, and the most preferred concentration is 0.1 mol/L dissolved therein sodium hydroxide.

The chloroauric acid solution, the bovine serum albumin solution and the 1-H-1,2,4-triazole-3-thiol solution were mixed evenly and then placed at 4°C for 0.5-2 hours, most preferably 1 hour.

The prepared gold nanocluster material aqueous solution is colorless, and has no absorption peak at 520 nm in the ultraviolet-visible spectrum. Under the irradiation of ultraviolet light, it produces strong rose-red fluorescence, and the maximum excitation wavelength and emission wavelength are 405 nm and 650 nm, respectively.

The preparation method of the best gold nanocluster fluorescent material of the present invention is as follows:

All glassware used in the following procedure was soaked in aqua regia, rinsed thoroughly with double distilled water, and allowed to dry. The gold nanocluster fluorescent material was prepared as follows: 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL was mixed with 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and 0.5 mL of 0.1 mol/L 1-H-1,2,4-triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, react at 4°C for 1 h to obtain 1-H-1,2 , 4-triazole-3-thiol-bovine serum albumin-gold nanoclusters. The obtained gold nanoclusters are reddish-brown liquid with strong rose-red fluorescence under the irradiation of ultraviolet lamp (365 nm).

The 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster prepared by the above-mentioned preparation method of the present invention is characterized in that it is easily soluble in water, and the aqueous solution is reddish brown , produces strong rose-red fluorescence under ultraviolet light irradiation, and the maximum excitation and emission wavelengths are 405 nm and 650 nm, respectively.

The average particle size of the gold nanoclusters is 2 nm.

The 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster is characterized in that the aqueous solution is placed in the dark at 4°C for 2 months without sedimentation , the fluorescence intensity and the position of the maximum emission peak remained unchanged.

The 1-H-1,2,4-triazole-3-thiol-bovine serum albumin-gold nanocluster is characterized in that chloroauric acid is the gold source, 1-H-1,2 , 4-triazole-3-thiol is used as a reducing agent and a modifying agent, and bovine serum albumin is used as a stabilizer.

Advantages of the present invention:

(1) In the present invention, 1-H-1,2,4-triazole-3-thiol is used as a reducing agent and a modifier, and a water-soluble gold nanocluster fluorescent material is synthesized in the next step in the presence of bovine serum albumin , which has the advantages of fast, simple and environmentally friendly preparation.

(2) The gold nanoclusters prepared by the present invention have strong rose-red fluorescence (maximum emission wavelength is 650 nm), large Stokes shift (245 nm) and other characteristics.

Description of drawings

Figure 1 shows the appearance of gold nanocluster fluorescent nanomaterials under visible light (A) and ultraviolet light (B).

Fig. 2 is an ultraviolet-visible absorption spectrum diagram of a gold nanocluster fluorescent nanomaterial.

Fig. 3 is the excitation and emission spectrum diagram of the gold nanocluster fluorescent nanomaterial.

Fig. 4 is an energy-scattering X-ray energy spectrum diagram of a fluorescent nanomaterial of a gold nanocluster.

Fig. 5 is a transmission electron microscope image of a gold nanocluster fluorescent nanomaterial.

Fig. 6 is an X-ray photoelectron energy spectrum diagram of a gold nanocluster fluorescent nanomaterial.

Detailed ways

Example 1:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The obtained gold nanoclusters are a reddish-brown liquid (see Figure 1A), which produces strong rose-red fluorescence under ultraviolet light (see Figure 1B).

Example 2:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The obtained gold nanocluster solution was scanned by ultraviolet-visible spectrum, and it was found that it had no characteristic absorption peak of gold nanoparticles at a wavelength of 520 nm (see FIG. 2 ).

Example 3:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The obtained gold nanocluster solution was scanned by fluorescence spectrum, and its maximum excitation wavelength and emission wavelength were 405 nm and 650 nm, respectively (see Figure 3).

Example 4:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The resulting gold nanocluster solution was drop-coated on a copper grid. Energy dispersive X-ray spectroscopy (see Figure 4) showed that the product contained gold.

Example 5:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The obtained gold nanocluster solution was measured by a transmission electron microscope, and the average particle size of the gold nanocluster was measured to be 2 nm (see FIG. 5 ).

Example 6:

Mix 0.75 mL of bovine serum albumin with a concentration of 50 mg/mL and 1.25 mL of chloroauric acid solution with a concentration of 10 mmol/L, and add 0.5 mL of 1-H-1,2,4- Triazole-3-thiol solution (containing 0.1 mol/L sodium hydroxide), shake and mix well, and react at 4°C for 1 h to obtain 1-H-1,2,4-triazole-3-thiol Alcohol-Bovine Serum Albumin-Gold Nanoclusters. The obtained gold nanocluster solution was freeze-dried to obtain a powder, and the obtained powder was measured by X-ray photoelectron spectroscopy. XPS Au(4f) showed that the gold 4f _7/2 peak and 4f _5/2 peak were located at 84.5 eV and 88.2 eV, respectively. eV, indicating that the valence states of gold in gold nanoclusters coexist in 0-valence and +1-valence modes (see Figure 6).

Claims (4)

1. a kind of 1-H-1, the preparation method of 2,4- triazole -3- mercaptan-bovine serum albumin(BSA)-fluorescent au nanocluster material, Comprise the following steps：The chlorine that the bovine serum albumin(BSA) and 1.25 mL concentration that 0.75 mL concentration is 50 mg/mL are 10 mmol/L Auric acid solution is uniformly mixed, and adds the 1-H-1 wherein containing 0.1 mol/L sodium hydroxides that 0.5 mL concentration is 0.1 mol/L, 2,4- triazole -3- thiol solutions, shaking mix, and when reaction 1 is small at 4 DEG C, obtain 1-H-1,2,4- triazole -3- mercaptan-ox Seralbumin-gold nano cluster, obtained gold nano cluster material aqueous solution is rufous, and uv-vis spectra is 520 Without absworption peak at nm, strong rose fluorescence, maximum excitation wavelength and launch wavelength are produced under 365 nm ultra violet lamps Respectively 405 nm and 650 nm.

2. 1-H-1,2,4- triazoles -3- mercaptan-bovine serum albumin(BSA)-gold nano cluster fluorescence according to claim 1 The preparation method of material, it is characterized in that using bovine serum albumin(BSA) as stabilizer, 1-H-1,2,4- triazole -3- mercaptan are reduction Agent and the formation of dressing agent control gold nano cluster.

3. 1-H-1,2,4- triazoles -3- mercaptan-bovine serum albumin(BSA)-gold nano cluster fluorescence according to claim 1 The preparation method of material, it is characterized in that gold nano cluster average grain diameter is 2 nm.

4. 1-H-1,2,4- triazoles -3- mercaptan-bovine serum albumin(BSA)-gold nano cluster fluorescence according to claim 1 The preparation method of material, occurs, fluorescence intensity and maximum it is characterized in that aqueous solution is placed 2 months under 4 DEG C of dark places without sediment Emission peak positions remain unchanged.