CN110788319A - Heating bowl-shaped Au-SiO2 nanoreactor and preparation method thereof - Google Patents

Abstract

The invention provides a heatable bowl-shaped Au-SiO ₂ nano-reactor and a preparation method thereof, wherein the preparation method comprises the following steps: Step 1: preparing a SiO ₂ nanosphere monolayer film on a carrier _; Nano-gold particles are grown on the nano-sphere monolayer film, and the SiO ₂ nano-spheres coated with nano-gold are peeled off from the carrier; Step 3: A bowl-shaped Au-SiO ₂ nano-reaction is prepared by using the SiO ₂ nano-spheres coated with nano-gold device. The morphology of the nano-reactor prepared by the method of the invention is bowl-shaped, which has advantages in light gathering and loading; because the particles are large, the photothermal efficiency is high, and the absorbable spectral range is wide; there are SiO ₂ nanometers near the nano-gold. The tablet can strengthen the fixing effect; the method of the present invention does not need to use a surfactant during the operation, avoids the toxicity risk brought by the surface modifier, and the finished product can be reused.

Description

Heating bowl-shaped Au-SiO2 nanoreactor and preparation method thereof

technical field

The invention relates to a heatable nano-reactor, namely the preparation technology of bowl-shaped Au-SiO ₂ , in particular to a method for using the photothermal effect of large-sized nano-gold particles to generate heat under illumination to trigger a reaction or improve reaction efficiency, etc. The characteristic preparation method of bowl-shaped Au- _SiO2 .

Background technique

The optical properties of plasmonic resonant metallic structures have attracted great attention in physical chemistry. More recently, the ability to focus light on the nanoscale has propelled their use in numerous photonics technologies (plasmons) and research efforts. The phenomenon of localized surface plasmon resonance (LSPR) enables the absorbed photons to partially generate heat through efficient photothermal conversion when a nanostructure is illuminated by a light beam. This effect opens up its application and development in many fields such as photothermal therapy, drug delivery, and catalysis. However, due to the limitations of morphology, size and other factors, the photothermal efficiency is also limited, and the low heat generation is one of the biggest problems limiting its application.

Among all metals, some noble metals exhibit strong absorption properties in the visible, near-infrared, or near-ultraviolet regions. Especially for gold nanoparticles, it has been demonstrated in photothermal applications, because gold nanoparticles are easy to prepare, easy to achieve multifunctionalization and tunable optical properties, the photothermal effect can be controlled by tuning the size, shape, composition and structure of plasmonic structures . Localized heating enables thermally assisted reactions to proceed efficiently in temperature-sensitive media such as biological environments. Various temperature-sensitive enzymes exist in nature, such as N-acetylneuraminic acid lyase, creatinine amide hydrolase, and cholesterol oxidase, whose optimum temperature is higher than room temperature or body temperature. However, few supports can load enzymes and simultaneously heat them for maximum catalytic efficiency.

SUMMARY OF THE INVENTION

In order to solve the defects of the prior art, the present invention provides a heatable bowl-shaped Au-SiO ₂ nano-reactor and a preparation method thereof, wherein the preparation method comprises the following steps:

Step 1: Preparation of _SiO2 nanosphere monolayer film on the carrier;

Step 2: growing gold nanoparticles on the _SiO2 nanosphere monolayer film, and peeling off the SiO2 nanospheres coated with gold nanoparticles from the carrier;

Step 3: Preparation of bowl-shaped Au- _SiO2 nanoreactors with nano-gold-coated _SiO2 nanospheres.

Further: the specific operation process of step 1 is: disperse _SiO2 amorphous nanospheres with a diameter of 100-600nm in ethylene glycol dimethyl ether or ethylene glycol methyl ether solution, and then move it into an evaporation tool to evaporate water Then a carrier coated with a single layer of _SiO2 nanospheres is obtained.

Further: the concentration of ethylene glycol dimethyl ether or ethylene glycol methyl ether solution is 20-150 mg/mL.

Further: the evaporation tool is a rotary evaporator.

Further: the specific operation process of step 2 is as follows: firstly, the carrier covered with single-layer SiO ₂ nanospheres is placed in the growth chamber, and then nano-gold with a thickness of less than 1 μm is grown on the surface of the single-layer SiO ₂ nanosphere film by sputtering , and then the SiO ₂ nanospheres coated with nano-gold were peeled off from the carrier and collected, dried and used for later use.

Further: control the thickness of gold nanoparticles by adjusting sputtering parameters.

Further: the SiO ₂ nanospheres coated with nano-gold are collected by placing the carrier in ultrapure water for ultrasonic oscillation.

Further: the specific operation process of step 3 is as follows: after dispersing the _SiO2 nanospheres coated with nano _- gold in ultrapure water, move it into the reaction kettle, then add NaBH to the reaction kettle and heat, and the reaction ends to obtain a For the finished product, the pre-finished product was washed to neutral pH, then dried and collected to obtain a bowl-shaped Au-SiO ₂ nanoreactor.

Further _: the SiO nanospheres coated with nano gold are dispersed in ultrapure water and the concentration of the solution made is 3-20mg/mL, and 1-40mL of this solution is added to the reactor, and the NaBH added _The concentration is 0.05 -2g/mL, the heating temperature is 70-120°C, the reaction time is 8-30 hours, and the obtained sample is washed with ultrapure water to neutral pH.

The present invention can heat the bowl-shaped Au-SiO ₂ nano-reactor, which is made by any one of the above-mentioned preparation methods.

Beneficial effects: the morphology of the nano-reactor prepared by the method of the present invention is bowl-shaped, which has advantages in light gathering and loading; because the particles are large, the photothermal efficiency is high, and the absorbable spectral range is wide; near the nano-gold there are long The SiO ₂ nanosheet can strengthen the immobilization effect; the method of the present invention does not need to use a surfactant during the operation, avoids the toxicity risk brought by the surface modifier, and the finished product can be reused.

Description of drawings

Fig. 1 is the transmission electron micrograph of the SiO nanosphere coated with nano-gold obtained in step ₂ in Example 1 of the present invention,

₂ is a scanning electron micrograph of the Au-SiO nanoreactor obtained in step 3 in Example 1 of the present invention,

3 is a transmission electron micrograph of the Au-SiO _nanoreactor obtained in step 3 in Example 1 of the present invention,

4 is a scanning transmission electron micrograph of the Au-SiO _nanoreactor obtained in step 3 in Example 1 of the present invention,

Fig. 5 is the Si element scanning mapping diagram of Au-SiO nanoreactor obtained in step ₃ in Example 1 of the present invention,

Fig. 6 is the scanning mapping diagram of O element of Au-SiO nanoreactor obtained in step ₃ in Example 1 of the present invention,

Fig. 7 is the Au element scanning mapping diagram of the Au-SiO nanoreactor obtained in step ₃ in Example 1 of the present invention,

8 is a high-power transmission electron micrograph of the Au-SiO nanoreactor obtained in step ₃ in Example 1 of the present invention,

Fig. 9 is the photothermal conversion analysis chart of the embodiment of the present invention and the comparative example under the wavelength of 532nm illumination,

Fig. 10 is the photothermal conversion analysis chart of the embodiment of the present invention and the comparative example under illumination with a wavelength of 765 nm,

FIG. 11 is an analysis chart of photothermal conversion under illumination with a wavelength of 1064 nm for the embodiment of the present invention and the comparative example.

Detailed ways

Below in conjunction with the accompanying drawings and specific embodiments, the present invention will be further clarified. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Modifications of equivalent forms all fall within the scope defined by the appended claims of this application.

The heatable bowl-shaped Au _- SiO nano-reactor of the present invention is made by the preparation method of the following steps:

Step 1: Disperse _SiO2 amorphous nanospheres with a diameter of 100-600nm in ethylene glycol dimethyl ether or ethylene glycol methyl ether solution with a concentration of 20-150mg/mL, and then move them into an evaporation tool, which It can be a rotary evaporator, and after evaporating the water, a carrier covered with a single layer of SiO ₂ nanospheres is obtained, so as to achieve the purpose of preparing a SiO ₂ nanosphere monolayer film on the carrier;

Step 2: First, place the carrier covered with single-layer SiO ₂ nanospheres in the growth chamber, control the thickness of gold nanoparticles by adjusting the sputtering parameters, and then use sputtering on the surface of the single-layer SiO ₂ nanosphere film Gold nanoparticles with a thickness of less than 1 μm are grown, and then the SiO ₂ nanospheres coated with gold nanoparticles are peeled off and collected from the carrier. _SiO2 nanospheres, dried for later use;

Step 3: After dispersing the _SiO2 nanospheres coated with gold nanoparticles in ultrapure water to prepare an aqueous solution of _SiO2 nanospheres coated with gold nanoparticles with a concentration of 3-20 mg/mL, take 1-40 mL of the solution and transfer it into The reaction kettle is added with a concentration of 0.05-2g/mL of NaBH ₄ and heated at 70-120 ° C for 8-30 hours, the reaction finishes to obtain a pre-finished product, and the pre-finished product is washed with ultrapure water to pH neutrality, It was then collected after drying to obtain a bowl-shaped Au- _SiO2 nanoreactor.

Example 1

Step 1: Preparation of _SiO2 nanosphere monolayer film on the support

Disperse 0.3 g of _SiO2 amorphous nanospheres with a diameter of 450 nm in 10 mL of ethylene glycol dimethyl ether by ultrasonic vibration, and spread the _SiO2 nanospheres on a glass sheet by a rotary evaporator to form a _SiO2 nanosphere monolayer film;

Step 2: Grow gold nanoparticles on the _SiO2 nanosphere monolayer film, peel off the _SiO2 nanospheres coated with nano-gold from the carrier, and take the _SiO2 nanospheres coated with nano-gold obtained in this step for electron Microscopic transmission, its morphology is shown in Figure 1;

The glass sheet covered with single-layer _SiO2 nanospheres is placed in the growth chamber, and a nano-gold particle layer with a thickness of 15 nm is grown on the surface of the single-layer _SiO2 nanosphere film by means of a small ion sputtering apparatus. Placed in ultrapure water and ultrasonically vibrated to collect SiO nanospheres coated with nano _- gold, and dried for later use;

Step 3: Preparation of bowl-shaped Au _- SiO nanoreactors with nano-gold _- coated SiO nanospheres

The SiO nanospheres coated with nano-gold obtained in step ₂ are dispersed in 5mL ultrapure water, the concentration is 3mg/mL, the obtained solution is added in the 20mL reactor, and NaBH is added ₍ concentration is 0.1g/mL) , placed in an oven with a temperature of 80 °C, and reacted for 12 hours. The obtained pre-finished product was washed with ultrapure water until the pH was neutral, dried and collected to obtain a bowl-shaped Au- _SiO2 nanoreactor, which was subjected to a series of electron microscopes. Scan and transmit as shown in Figure 2-8.

Example 2

The ethylene glycol dimethyl ether of step 1 in Example 1 was replaced with ethylene glycol methyl ether, and other steps and conditions were consistent with those of Example 1.

Example 3

Change the weight of _SiO2 amorphous nanospheres in step 1 in Example 1 to 0.5 g, and the other steps and conditions are the same as those in Example 1.

Example 4

The thickness of the gold nanoparticle layer in step 2 in Example 1 was changed to 30 nm, and other steps and conditions were the same as those in Example 1.

Example 5

The thickness of the gold nanoparticle layer in step 2 in Example 1 was changed to 50 nm, and other steps and conditions were the same as those in Example 1.

Example 6

The thickness of the gold nanoparticle layer in step 2 in Example 1 was changed to 80 nm, and other steps and conditions were the same as those in Example 1.

Example 7

The concentration of _SiO2 nanospheres in step 3 in Example 1 was changed to 5 mg/mL, and other steps and conditions were kept the same as those in Example 1.

Example 8

The reaction time of step 3 in Example 1 was changed to 24h, and other steps and conditions were consistent with Example 1.

Example 9

The reaction temperature of step 3 in Example 1 was changed to 100° C., and other steps and conditions were the same as those in Example 1.

The finished products obtained in the 7 examples were subjected to electron microscope scanning and transmission detection, and the bowl-shaped Au-SiO ₂ nanoreactors as shown in Figures 2-6 were obtained.

Comparative Example 10

The processing procedure of step 3 is deleted, and other steps and conditions are the same as those in embodiment 1.

Comparative Example 11

The processing procedures of steps 1 and 2 were deleted, and _SiO2 nanospheres were directly used in step 3, and other steps and conditions were kept the same as those in Example 1.

Comparative Example 12

In Example 8, the mode of medium-loading gold nanoparticles in step 2 was changed to stirring, and the other steps and conditions were the same as those in Example 8.

The samples obtained in the examples and comparative examples were subjected to photothermal effect tests under illumination of different wavelengths and different powers, and the results are shown in Figures 9-11. For comparison, gold nanoparticles supported on silica capsules, Au-silica spheres, Au-silica bowls and immobilized on silica capsules were tested at different sputtering times. The Au-silica samples are responsive to illumination with broad wavelengths from UV to NIR. As shown in Figures 9-11, silica capsules cannot generate heat, so gold nanoparticles are a unique heat resource in these gold-silica systems. The temperature of Au nanoparticles loaded on silica capsules can be increased by 60 °C and 48 °C when irradiated with 532 nm laser of 90 mW and 60 mW, respectively. However, when the power was reduced (30mW) or the wavelength was getting higher and higher, the gold nanoparticles on the silica gel produced almost no heat. The temperature of the Au-silica spheres is much higher than that of the gold nanoparticles supported on silica capsules, because the size of the gold nanoparticles by sputtering is tens of times larger than that of the synthesized gold nanoparticles. The temperature of the Au-silica bowl is higher than that of the Au-silica sphere due to the morphology of the open shell structure of the gold nanoparticles. In all cases, the temperature increased with the size of the gold nanolayers.

Claims (10)

1. the preparation method of heating bowl-shaped Au-SiO nano _- reactor, is characterized in that: comprise the following steps: Step 1: Preparation of _SiO2 nanosphere monolayer film on the carrier; Step 2: growing gold nanoparticles on the SiO ₂ nanosphere monolayer film, and peeling off the SiO ₂ nanospheres coated with nano gold from the carrier; Step 3: Preparation of bowl-shaped Au- _SiO2 nanoreactors with nano-gold-coated _SiO2 nanospheres. 2. The preparation method of the heatable bowl-shaped Au _- SiO nano-reactor according to claim 1, characterized in that: the specific operation process of step ₁ is: dispersing SiO amorphous nano-spheres with a diameter of 100-600nm in the ethylene glycol dimethyl ether or ethylene glycol methyl ether solution, and then move it into an evaporation tool to evaporate the water to obtain a carrier covered with single-layer SiO ₂ nanospheres. 3. The method for preparing a heatable bowl-shaped _SiO2 nanoreactor according to claim 2, wherein the concentration of the ethylene glycol dimethyl ether or ethylene glycol methyl ether solution is 20-150 mg/mL. 4. The method for preparing a heatable bowl-shaped _SiO2 nanoreactor according to claim 2, wherein the evaporation tool is a rotary evaporator. 5. The preparation method of the heatable bowl-shaped SiO nano _- reactor according to claim 1, characterized in that: the specific operation process of step ₂ is: firstly, the carrier covered with single-layer SiO nano-spheres is placed in the growth chamber , and then sputtering is used to grow nano-gold with a thickness of less than 1 μm on the surface of the single-layer SiO ₂ nanosphere film, and then the SiO ₂ nano-spheres coated with nano-gold are peeled off from the carrier and collected, dried and used for later use. 6 . The method for preparing a heatable bowl-shaped Au-SiO ₂ nanoreactor according to claim 5 , wherein the thickness of the gold nanoparticles is controlled by adjusting sputtering parameters. 7 . 7. The preparation method of the heatable bowl-shaped Au-SiO ₂ nano-reactor according to claim 5, characterized in that: by placing the carrier in ultrapure water and carrying out ultrasonic vibration to collect the nano-gold coated _SiO2 nanospheres. 8. The preparation method of the heatable bowl-shaped Au-SiO nanoreactor according to claim ₁ , characterized in that: the specific operation process of step ₃ is: the SiO nanospheres coated with nano-gold are dispersed in ultrapure After the water, it was moved into the reaction kettle, then NaBH was added to the reaction kettle and heated, the reaction was completed to obtain a pre _- finished product, the pre-finished product was washed to a neutral pH, and then dried and collected to obtain a bowl-shaped Au-SiO ₂ Nanoreactor. 9. the preparation method of the heated bowl-shaped Au-SiO ₂ nano-reactor according to claim 8, is characterized in that: the SiO ₂ nano balls coated with nano-gold are dispersed in ultrapure water and the concentration of the solution made is 3-20mg/mL, and get this solution 1-40mL and add it in the reactor, the NaBH that adds Concentration is _0.05-2g /mL, and heating temperature is 70-120 ℃, and the reaction time is 8-30 hours, and the sample obtained is with Wash with ultrapure water to neutral pH. 10. A heatable bowl-shaped Au- _SiO2 nanoreactor, characterized in that: it is made by the preparation method described in any one of the preceding claims.

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