A fluorescence-enhanced noble metal nanomaterial and a fluorescence wavelength adjustment method

Abstract

The present invention discloses a fluorescence-enhanced noble metal nanomaterial and a method for adjusting fluorescence wavelength. First, a noble metal fluorescence pressure sensing material is provided, which is composed of a gold complex layer and a phosphine ligand layer covering the gold complex layer, and can display a fluorescence pressure trajectory under pressure; in addition, a fluorescence-enhanced noble metal nanomaterial is provided, which is obtained by mixing and fully grinding a gold complex and a phosphine ligand, has a strong golden fluorescence, and has a certain thermal stability. After synthesis, the fluorescence performance is greatly improved compared with the fluorescence intensity of the precursor complex. The present invention can realize the ligand exchange of the complex through simple operation; the fluorescent material can realize the adjustment of the fluorescence wavelength under different states. The fluorescent material of the present invention can be applied to the field of pressure tracking sensors, and has important potential application value in the fields of organic light-emitting diodes, fluorescent probes, biological imaging and fluorescence sensing.

Description

Technical Field

[0001] The present invention belongs to the technical field of precious metal nano fluorescent materials, and specifically relates to a fluorescence enhanced precious metal nano material and a fluorescence wavelength adjustment method. The material may be applied to the field of pressure sensors. Background Art

[0002] The development of metal complexes is not only limited to applications in catalysts and as precursors for cluster synthesis, but is also widely used in organic light-emitting diodes, anti-tumor therapy, food testing, fluorescent probes, and bioimaging. Therefore, precious metal complex fluorescent materials have received widespread attention.

[0003] The existing methods for enhancing the fluorescence of complexes mainly include heterometallic doping and designing new ligands, but these two methods are too cumbersome and difficult to operate. The method of using existing ligands and substrates for ligand exchange is a relatively mature solution. Ligand exchange is also widely used in cluster structure enhancement and size conversion between clusters. Therefore, it is necessary to develop a simple method that can achieve complex fluorescence enhancement and high-yield ligand exchange. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a fluorescence-enhanced precious metal nanomaterial and a method for adjusting the fluorescence wavelength, which provides a new idea for designing and enhancing the fluorescence performance of fluorescent nanomaterials, and can also achieve the purpose of ligand exchange in the complex. The precious metal fluorescent nanomaterial of the present invention exhibits excellent fluorescence performance and has a certain thermal stability; its fluorescence performance after synthesis is greatly improved compared with the fluorescence intensity of the precursor complex. Tests show that the material has excellent fluorescence properties, with a quantum yield of up to 79% and a fluorescence lifetime of 9μs. The preparation method provided by the present invention has a high substrate utilization rate, and the fluorescent material can be obtained without additional purification. It has important potential application value in the fields of organic light-emitting diodes, fluorescent probes, biological imaging and fluorescence sensing.

[0005] One of the purposes of the present invention is to provide a noble metal fluorescent pressure sensing material, which is composed of a gold complex layer and a phosphine ligand layer covering the gold complex layer, and can display a fluorescent pressure trajectory under pressure. Figure 6 shown.

[0006] The pressure is ≥20N.

[0007] The molecular formula of the gold complex is Au2C 27 H 26 P2Cl2, its structure is shown below:

[0008]

[0009] The structure of the phosphine ligand is:

[0010]

[0011] The second object of the present invention is to provide a fluorescence enhanced noble metal nanomaterial, which is obtained by mixing and fully grinding a gold complex and a phosphine ligand, denoted as M gri , with strong golden fluorescence. Its fluorescence enhancement effect is as follows Figure 2 As shown. gri Fluorescence correlation test was performed, and the results were as follows Figure 3 As shown, M gri The fluorescence wavelength is 550±20nm.

[0012] The molecular formula of the gold complex is Au2C 27 H 26 P2Cl2, its structure is shown below:

[0013]

[0014] The structure of the phosphine ligand is:

[0015]

[0016] The gold complex is prepared by the following method:

[0017] 1 mL of HAuCl4 was added to an eggplant-shaped bottle, 220 mg of 1,3-bis(diphenylphosphino)propane was added, and ethanol solution was added. The solution was stirred until the color of the solution slowly changed from golden yellow to milky white. The stirring was stopped. After the stirring was stopped, the solution was rotary evaporated to dryness, and the product was washed and dried to obtain a gold complex, which was recorded as M. sub The present invention synthesizes the above metal complex and adds a foreign similar ligand with a shorter chain, and fluorescence enhancement can be achieved without adding a solution reaction.

[0018] The third object of the present invention is to provide a method for adjusting the fluorescence wavelength of fluorescence-enhanced noble metal nanomaterials, comprising the following steps:

[0019] (1) Take the fluorescence enhancing noble metal nanomaterial M gri Add methanol solution into the eggplant-shaped bottle and stir until the white solid gradually disappears and the solution gradually turns into a light yellow clear transparent solution. Stop the reaction and record the sample as M gri -MeOH. The fluorescence data of the sample is measured as follows Figure 4 As shown, the fluorescence wavelength is 600±20nm. gri It is not the state after ligand exchange has occurred, but M subAfter adding methanol and stirring, a ligand exchange reaction can occur to obtain M gri -MeOH is the product after ligand exchange, which is a mixture.

[0020] (2) Take M gri -MeOH sample was added dropwise on the glass plate and dried. The sample was recorded as M gri -MeOH-Dry. The fluorescence data of the sample is measured as follows Figure 4 As shown, the fluorescence wavelength is 510±20nm. gri -MeOH is also a mixture after methanol is removed.

[0021] (3) After the reaction of step (2) is completed, the product is rotary evaporated, washed and dried to obtain a white solid product, which is recorded as M gri -MeOH-Wash-Dry. The fluorescence data of the sample is measured as follows Figure 4 As shown, the fluorescence wavelength is 468±20nm. gri -MeOH-Wash-Dry is M gri -MeOH-Dry removes the exchanged ligands to obtain a compound with a specific structure.

[0022] Take the dried product M gri -MeOH-Wash-Dry Add dichloromethane solution to fully dissolve the product, add it to the single crystal bottle, cover the top with poor solvent ether, and it will crystallize after two days. Its structure is as follows Figure 5 The chemical formula is Au2C 50 H 44 P4Cl2, the structure is as follows:

[0023]

[0024] The crystal data was measured; the molecular weight was 1233.57 g / mol, belonging to the triclinic system, the space group was P-1, and the unit cell parameters were alpha=101.469(5) o , beta = 107.066(4) o , gamma = 98.991(5) o , Z = 2. It is transparent, colorless, blocky crystals, tasteless, insoluble in water, and easily soluble in ethanol solution.

[0025] Optical performance tests show that the provided fluorescent nanomaterial M griIt has good gold fluorescence performance and very strong luminescence intensity, and is expected to be used in the field of pressure tracking sensors. It is also expected to have important application value in the fields of organic light-emitting diodes, fluorescent probes, biological imaging and fluorescent sensing. Figure 3 shown.

[0026] The beneficial effects of the present invention are embodied in:

[0027] The noble metal fluorescent nanomaterial M of the present invention gri It is prepared by a simple grinding synthesis method. The preparation method adopted by the present invention has the advantages of simplicity, high efficiency, repeatability and no pollution. The fluorescent nanomaterial provided by the present invention has a high quantum yield, exhibits excellent fluorescence properties, and has good thermal stability, and a ligand exchange method can be realized in the solution. gri The fluorescence wavelength can also be adjusted in different states. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the synthesis route of the present invention;

[0029] Figure 2 Fluorescence comparison of gold complex and foreign similar ligand before and after grinding under UV light irradiation;

[0030] Figure 3 a is the fluorescence image of grinding different substrate ratios, b is the emission intensity test comparison before and after grinding;

[0031] Figure 4 M gri Comparison of fluorescence wavelengths under different conditions;

[0032] Figure 5 This is the crystal structure of the product after ligand exchange, and the molecular formula is Au2C 50 H 44 P4Cl2;

[0033] Figure 6 is the pressure trajectory fluorescence image;

[0034] Figure 7 M gri Comparison of fluorescent colors in different states. From left to right: M gri 、M gri -MeOH, M gri -MeOH-Dry, M gri -MeOH-Wash-Dry. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to the examples. Unless otherwise specified, the raw materials or equipment used in the present invention are all commercially available.

[0036] Embodiment 1:

[0037] S1. Use a 1ml pipette to measure 1ml of HAuCl4 and add it to an eggplant-shaped bottle. Add 220mg of 1,3-bis(diphenylphosphino)propane, 50ml of ethanol solution, and a magnetic bar of appropriate size. Stir at 1500rpm for 6h. The color of the solution slowly changes from golden yellow to milky white. Stop stirring. The concentration of chloroauric acid added is 0.2g / ml.

[0038] S2. After stopping stirring, the solution was evaporated to dryness by rotary evaporation. The dried product was washed 2×2 times with ethanol and ether respectively, centrifuged, and placed in a drying oven at 60-70°C for 24 hours. The sample was recorded as M sub The fluorescence data of the sample is shown in the figure below. Figure 3 The sample has almost no fluorescence.

[0039] S3, weigh the dried sample M in step S2 sub 50 mg, weigh 44 mg (2 equivalents) of bis(diphenylphosphino)methane, add both into a mortar at the same time, and grind them thoroughly in the mortar with a pestle for 10 min. The sample is recorded as M gri Measure the fluorescence data of the sample as follows Figure 3 shown.

[0040] Note: To determine the appropriate grinding ratio for the strongest fluorescence, adjust M sub The ratio of bis(diphenylphosphino)methane was ground and the fluorescence was measured as Figure 3 shown.

[0041] S3-1. Take sample M sub 50 mg, weigh 22 mg (1 equivalent) of bis(diphenylphosphino)methane, add both into a mortar at the same time, and grind them thoroughly in the mortar with a pestle for 10 min. The sample is recorded as M gri -1, measured fluorescence as Figure 3 shown.

[0042] S3-2, take sample M sub 50 mg, weigh 44 mg (2 equivalents) of bis(diphenylphosphino)methane, add both into a mortar at the same time, and grind them thoroughly in the mortar with a pestle for 10 min. The sample is recorded as M gri -2, the fluorescence was measured as Figure 3 shown.

[0043] S3-3, take sample M sub 50 mg, weigh 66 mg (3 equivalents) of bis(diphenylphosphino)methane, add both into a mortar at the same time, and grind them thoroughly in the mortar with a pestle for 10 min. The sample is recorded as M gri -3, measured fluorescence as Figure 3 shown.

[0044] In summary, the ratio in S3-2 is the best fluorescence.

[0045] Embodiment 2:

[0046] S4, based on the fluorescent material obtained in S3, take the sample M in this step gri 50 mg was added to an eggplant-shaped bottle, 50 ml of methanol solution was added, and a magnetic rod of appropriate size was added to stir for 30 min. The white solid gradually disappeared and the solution gradually turned into a light yellow clear and transparent solution. The reaction was stopped and the sample was recorded as M gri -MeOH. The fluorescence data of the sample is measured as follows Figure 4 shown.

[0047] S5, take M gri -1 ml of MeOH solution sample was slowly dripped onto a glass plate and dried at 60°C. After drying, the glass plate was covered with a translucent white solid, which was recorded as M gri -MeOH-Dry. The fluorescence data of the sample is measured as follows Figure 4 shown.

[0048] S6. After the reaction is completed, the vacuum rotary evaporator is connected to vacuum rotary evaporate the solution to obtain a white solid, which is washed 2×2 times with n-hexane and ether respectively, centrifuged, and placed in a drying oven at 60-70°C for 24 hours to obtain a white solid product, which is recorded as Mgri-MeOH-Wash-Dry. The fluorescence data of the sample is shown in Figure 4.

[0049] S7, take 20mg S6 dry sample Mgri-MeOH-Wash-Dry, add 1ml dichloromethane solution, fully dissolve the product, slowly drop it into a 5ml single crystal bottle, slowly drop ether solution on the top to the top and plug the bottle stopper. After two days, the ligand exchanged gold complex can be obtained, and its structure is as follows Figure 5 As shown, the product after ligand exchange has a very high crystal yield (60%).

[0050] In summary, we can obtain the ligand exchange product by adding solvent and stirring, and the crystalline product is easy to obtain.

[0051] Embodiment 3:

[0052] S8, take 50mg M sub Cover it on the grinding plate, and then evenly cover it with a layer of bis(diphenylphosphine)methane ligand. Under the action of pressure, the fluorescence pressure trajectory diagram can be displayed, such as Figure 6 shown.

[0053] The beneficial effects of the present invention are:

[0054] In this synthesis method, a fluorescent material with high quantum yield and long fluorescence lifetime can be obtained by simply adding ligands to a complex with almost no fluorescence and grinding them. In the synthesis process of this material, it is not necessary to add a large amount of solvent and stir the method as in the traditional compound synthesis. This method provides a new idea for enhancing the basic properties of fluorescent materials; this invention can realize the function of fine-tuning the length of ligands in metal complexes; this invention M gri The sample can realize the function of adjusting the fluorescence wavelength in different states; the invention M gri Or it can be applied to the field of pressure tracking sensors. The invention may be applied in the field of pressure tracking sensors. The pressure trajectory fluorescence image is as follows Figure 6 shown.

Claims

1. A noble metal fluorescent pressure sensing material, characterized in that: The noble metal fluorescent pressure sensing material is composed of a gold complex layer and a phosphine ligand layer covering the gold complex layer, and can display a fluorescent pressure track under pressure; The molecular formula of the gold complex is Au2C 27 H 26 P2Cl2, its structure is shown below: The structure of the phosphine ligand is:

2. The noble metal fluorescent pressure sensing material according to claim 1, characterized in that: The pressure is ≥20N.

3. A fluorescence-enhanced noble metal nanomaterial, characterized in that: The fluorescence enhanced noble metal nanomaterial is obtained by mixing and fully grinding the gold complex and the phosphine ligand, and is denoted as M gri , with strong golden fluorescence; The molecular formula of the gold complex is Au2C 27 H 26 P2Cl2, its structure is shown below: The structure of the phosphine ligand is:

4. The fluorescence enhanced noble metal nanomaterial according to claim 3, characterized in that: The amount of the gold complex added is 50 mg, and the amount of the phosphine ligand added is 22-66 mg.

5. The fluorescence enhanced noble metal nanomaterial according to claim 4, characterized in that: The amount of the gold complex added was 50 mg, and the amount of the phosphine ligand added was 44 mg.

6. A method for adjusting the fluorescence wavelength of fluorescence-enhanced noble metal nanomaterials according to claim 3, characterized in that The steps include: (1) Take the fluorescence enhancing noble metal nanomaterial M gri Add methanol solution into the eggplant-shaped bottle and stir until the white solid gradually disappears and the solution gradually turns into a light yellow clear transparent solution. Stop the reaction and record the sample as M gri -MeOH, fluorescence wavelength is 600±20nm; (2) Take M gri -MeOH sample was added dropwise on the glass plate and dried. The sample was recorded as M gri -MeOH-Dry, fluorescence wavelength is 510±20nm; (3) After the reaction of step (1) is completed, the product is rotary evaporated, washed and dried to obtain a white solid product, which is recorded as M gri -MeOH-Wash-Dry, the fluorescence wavelength is 468±20nm.

7. The method according to claim 6, characterized in that: In step (3), the washing reagents are n-hexane and ether.

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