CN112098390B - Surface enhanced Raman scattering substrate and preparation method thereof - Google Patents
Surface enhanced Raman scattering substrate and preparation method thereof Download PDFInfo
- Publication number
- CN112098390B CN112098390B CN202010971591.2A CN202010971591A CN112098390B CN 112098390 B CN112098390 B CN 112098390B CN 202010971591 A CN202010971591 A CN 202010971591A CN 112098390 B CN112098390 B CN 112098390B
- Authority
- CN
- China
- Prior art keywords
- zno
- silver
- nano
- tower
- raman scattering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/65—Raman scattering
- G01N21/658—Raman scattering enhancement Raman, e.g. surface plasmons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
- B22F1/054—Nanosized particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
- B22F1/054—Nanosized particles
- B22F1/0553—Complex form nanoparticles, e.g. prism, pyramid, octahedron
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
Abstract
The invention provides a surface-enhanced Raman scattering substrate which comprises tetrahedral and cubic silver nanoparticles and a ZnO nano-tower array, wherein the average diameter of the tetrahedral and cubic silver nanoparticles is about 50-110 nm, the ZnO nano-tower is similar to a hexagonal prism, the diameter of the prism at the tip is gradually reduced to form a step-shaped appearance, the average length of the ZnO nano-tower is 2-4 mu m, and the average diameter at the high half-length is 500-800 nm. The surface-enhanced Raman scattering substrate provided by the invention has an excellent enhancement effect.
Description
Technical Field
The invention relates to the technical field of Surface-enhanced Raman detection, in particular to a preparation method of a silver nanoparticle/ZnO nano-tower Surface-enhanced Raman Scattering (SERS) substrate.
Background
In 1928, Raman was found by c.v. Raman. The laser in the 60 s greatly improved the excitation efficiency, became the ideal light source of Raman spectrum, and the research of Raman scattering entered the brand-new period. The development of monochromators, detectors, optical microscopes, weak signal detection technologies and computer technologies in the later period makes the raman spectroscopy technology make great progress in many fields such as chemistry, physics and biology. Currently, raman spectroscopy is widely used in the fields of materials, chemical engineering, petroleum, polymers, biology, environmental protection, geology and the like.
The Raman scattering effect is very weak and its scattered light intensity is about 10 of the incident light intensity-6～10-9The application and development of raman spectroscopy are greatly limited. In 1974, Fleischmann et al found that the Raman signal intensity of the tt spin molecules adsorbed on the rough surface of the gold and silver was greatly improved, and the signal intensity was changed along with the change of the applied potential of the electrode. In 1977, the enhancement effect related to rough surfaces of silver, gold, copper and the like is called Surface Enhanced Raman Scattering (SERS) effect, and the corresponding spectrum is called Surface enhanced Raman spectrum through systematic experimental research and theoretical calculation by Jeanmaire, Van Duyne, Albrecht and creeton and the like. Subsequently, SERS phenomena were also observed on other rough surfaces.
Since the past decades, SERS spectroscopy has attracted much attention as a rapid, non-destructive, and environmentally friendly means for high sensitivity detection in the fields of chemistry, food, pharmacy, and biomolecules. The largest raman signal and a large proportion of the average enhancement on a SERS substrate are usually from highly localized locations of very high enhancement (hot-spots). Therefore, the preparation of the SERS substrate carrying high-density hot spots is very important to further reduce the detection limit of the substrate to expand the application field of the SERS technology, especially for the recently researched very hot single-molecule raman detection technology. The main sources of hotspots include: the nanogap of the metal particles and the nanotip of the metal, and thus the hot spot density of the substrate can be improved from both aspects. In addition, Eric c. Le Ru et al report that to obtain high signal enhancement from hot spots, the molecules to be tested must be close to or located in the hot spot region (typically required to be less than 10 nm), which is of little concern and very challenging.
Conventional SERS substrates are composed of pure noble metals, but such substrates are expensive and have high technical requirements, which are not suitable for practical applications. Recently, the noble metal/semiconductor heterogeneous SERS substrate has received attention because it not only has electromagnetic enhancement of a pure noble metal substrate, but also has strong chemical enhancement through electron transfer among the noble metal, the semiconductor, and the molecule to be measured, and further, various structures of the semiconductor can carry numerous noble metal particles to realize a high-density three-dimensional hot spot. Among them, silver/ZnO heterogeneous substrates have been extensively studied due to the changeable structure of ZnO and electron transfer resonance caused by the work function difference between silver and ZnO. However, the current preparation methods of silver/ZnO heterogeneous substrates mainly comprise ion sputtering, chemical plating, photochemical reduction, electrodeposition and the like, and have several disadvantages:
firstly, the preparation equipment is expensive, the SERS substrate with low detection limit and practical application value is difficult to prepare on a large scale in a simple and cheap mode,
secondly, the silver/ZnO heterogeneous substrate prepared by the existing method is not ideal for enhancing the Raman spectrum, and has a great room for improvement.
Disclosure of Invention
In order to further improve the enhancement effect of the silver/ZnO heterogeneous substrate on the raman spectrum and to develop a simpler method for preparing the silver/ZnO heterogeneous surface enhanced raman scattering substrate, the inventors of the present invention have conducted intensive studies and, as a result, have found and provided a simple and inexpensive method for preparing the surface enhanced raman scattering substrate and a surface enhanced raman scattering substrate having high sensitivity.
Specifically, the invention provides a surface-enhanced Raman scattering substrate which comprises tetrahedral and cubic silver nanoparticles and a ZnO nano-tower array, wherein the average diameter of the tetrahedral and cubic silver nanoparticles is about 50-110 nm, the ZnO nano-tower is similar to a hexagonal prism, the diameter of the prism is gradually reduced at the tip to form a step-shaped appearance, the average length of the ZnO nano-tower is 2-4 μm, and the average diameter at the height of the half body is 500-800 nm.
The preparation method of the surface enhanced Raman scattering substrate comprises the following steps:
dissolving inorganic silver salt and polyvinylpyrrolidone in an organic solvent, uniformly mixing, heating and reacting at 160-180 ℃ for 20-24 hours, cooling to room temperature, purifying a product, and dispersing the product in ethanol to obtain nano silver sol;
a nanometer tower preparation process, namely suspending the silicon wafer subjected to hydroxylation treatment in a ZnO nanometer tower growth solution formed by zinc chloride and ammonia water, sealing and heating to 85-95 ℃, carrying out reaction for 50-90 minutes to grow a ZnO nanometer tower array, taking out the silicon wafer after the reaction is finished, and cleaning and drying the silicon wafer to obtain the ZnO nanometer tower array;
and an assembling procedure, namely dripping the nano silver sol into a ZnO nano tower array, thereby assembling and obtaining the silver/ZnO nano tower surface enhanced Raman scattering substrate.
According to the method, firstly, nano silver sol consisting of tetrahedral and cubic silver nanoparticles is synthesized by a solvothermal method, then a ZnO nano tower array is prepared on a silicon substrate by a chemical bath deposition method, and finally, the silver sol is combined with the ZnO nano tower array by a drop casting method.
Drawings
Fig. 1 a and b are TEM images of silver sols of different particle sizes prepared in the present invention;
FIG. 2 is an SEM image of a ZnO nano-tower prepared in the present invention, wherein a and b are two parallel ZnO nano-towers prepared with ammonia water dosage of 2ml and reaction time of 75min, respectively;
FIG. 3 is an SEM image of a silver nanoparticle/ZnO nanocolumn base prepared in the present invention, in which a and b are an overall view and a partially enlarged view of a tip of the silver nanoparticle/ZnO nanocolumn base, respectively;
FIG. 4 is an XRD pattern of a silver nanoparticle/ZnO nanorod substrate prepared in the present invention;
FIG. 5a is a graph of silver nanoparticle/ZnO nanocatalyst baseline assay 10 prepared in the present invention-7～ 10-18Raman spectrum of mol/L rhodamine, FIG. 5b is detection 10-16、10-18An amplified Raman spectrum of mol/L R6G;
FIG. 6 is an SEM image of the preparation of silver nanoparticle/ZnO nanorods for comparison in the present invention. (a) Top view, (b) cross-sectional view;
FIG. 7 shows that the dropping concentration is 10 on the ZnO nano-tower substrate and the ZnO nano-rod substrate respectively-7 M R6 SERS spectrum of 6G solution;
fig. 8 is a TEM image of silver sols of different particle size and morphology prepared at different reaction times. (a) 11 hours, (b) 12 hours, (c) 14 hours, (d) 16 hours, (e) 22 hours, (f) 44 hours;
fig. 9 is a graph of raman signals collected from R6G drops cast onto the base of spherical silver nanoparticles/ZnO nanocatalys.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The invention provides a surface-enhanced Raman scattering substrate which comprises tetrahedral and cubic silver nanoparticles and a ZnO nano-tower array, wherein the average diameter of the tetrahedral and cubic silver nanoparticles is about 50-110 nm, the ZnO nano-tower is similar to a hexagonal prism, the diameter of the prism at the tip is gradually reduced to form a step-shaped appearance, the average length of the ZnO nano-tower is 2-4 mu m, and the average diameter of the high half of the body is 500-800 nm.
The surface enhanced Raman scattering substrate is formed by scattering tetrahedral and cubic silver nanoparticles on a ZnO nano tower array, wherein the shapes of the tetrahedrons and the cubes of the silver nanoparticles are very important, and the inventor of the invention also tests the combination of the spherical silver nanoparticles and the ZnO nano tower and finds that the surface enhancing effect is greatly reduced because: the corners of tetrahedral and cubic silver nanoparticles can focus light into the nanoscale volume near the corners and significantly increase the near-field intensity of these regions, creating hot spots at the tips of the metal nanoparticles. Preferably, the tetrahedral and cubic silver nanoparticles have an average diameter of about 60 to 80 nm. In addition, the ZnO nano-tower is similar to a hexagonal prism in shape, the diameter of the prism is gradually reduced at the tip, and the step-shaped appearance is very important. The inventors also tested the combination of columnar ZnO nanorods with nano-silver particles, and found that the surface enhancement effect was much reduced compared to the inventive morphologic ZnO nanocatalyst. The ZnO nano tower is similar to a hexagonal prism in shape, the diameter of the prism at the tip is gradually reduced, and the stepped shape can bring better surface enhancement effect of the Raman spectrum, and the reason is that: the step shape can not only enable the silver nano particles to be located on the steps, but also reduce the kinetic energy of the solution to be detected, and the solution to be detected is left near the silver nano particles on the steps, so that the aim of enabling molecules to be detected to be closer to a hot spot area is fulfilled. Preferably, the ZnO nano-tower has an average length of 2.5 to 3.5 μm and an average diameter at the height of the half body of 650 to 750 nm.
Silver nanoparticles have a variety of morphologies. The ZnO nano material has different shapes according to different preparation methods, such as a common nanorod structure and a nano tower structure of the invention. The low detection limit silver/ZnO heterogeneous surface enhanced Raman scattering substrate provided by the invention exerts two hot spot effects of a nanometer gap and a tip through the combination of the silver nanometer particles with the specific morphology and the ZnO nanometer tower with the specific morphology, and can retain molecules to be detected in a hot spot area, so that the Raman spectrum enhancement effect is greatly improved in the test. When rhodamine 6G (hereinafter also referred to as R6G) was used as the molecule to be detected, the lowest detectable concentration was 1X 10-18Results in mol/L, which is superior to most of the silver reported so far/ZnO heterogeneous SERS substrate.
The preparation method of the surface enhanced Raman scattering substrate comprises the following steps:
dissolving inorganic silver salt and polyvinylpyrrolidone in an organic solvent, uniformly mixing, heating and reacting at 160-180 ℃ for 20-24 hours, cooling to room temperature, purifying a product, and dispersing the product in ethanol to obtain nano silver sol;
a nanometer tower preparation process, namely suspending the silicon wafer subjected to hydroxylation treatment in a ZnO nanometer tower growth solution formed by zinc chloride and ammonia water, sealing and heating to 85-95 ℃, carrying out reaction for 50-90 minutes to grow a ZnO nanometer tower array, taking out the silicon wafer after the reaction is finished, and cleaning and drying the silicon wafer to obtain the ZnO nanometer tower array;
and an assembling procedure, namely dripping the nano silver sol into a ZnO nano tower array, thereby assembling and obtaining the silver/ZnO nano tower surface enhanced Raman scattering substrate.
In the preparation process of the nano-silver sol, the nano-silver sol is synthesized by a solvothermal method, the inorganic silver salt is typically silver nitrate, and the feeding amount of the general polyvinylpyrrolidone is 8 to 20 parts by mass, preferably 9 to 10 parts by mass, relative to 1 part by mass of the silver nitrate. The organic solvent is preferably N, N-dimethylformamide in view of solubility, but is not limited thereto, and the amount of the solvent to be charged may be an appropriate amount, and is generally 100 to 1000 parts by mass relative to silver nitrate. Typical laboratory procedures for preparing silver sols composed of tetrahedral and cubic silver nanoparticles, for example:
dissolving 0.01-0.04 g silver nitrate and 0.155-0.4 g polyvinylpyrrolidone (PVP, K85-95, Mw = 1300000) in 20-60 ml N, N-dimethylformamide (DMF, purchased from ALADDIN) solution, and stirring with magnetic force for 30-50 min to light yellow. And transferring the light yellow solution into a reaction kettle, and heating to 160-180 ℃ for reaction for 20-24 h. After completion of the reaction, the autoclave was immediately taken out and cooled to room temperature in running water. Repeatedly using ethanol for centrifugal purification of the product, and finally dispersing the product in 10-30 mL of ethanol to obtain the product with the concentration of 2 multiplied by 10-4g/ml～2.5×10-3g/ml of nano silver sol.
The inventor finds that in order to obtain tetrahedral and cubic silver nanoparticles with the particle size of 50-110 nm, it is important to control the heating reaction at 160-180 ℃ for 20-24 hours, and the inventor monitors the change of the morphology and the particle size of the silver nanoparticles in the above-mentioned reaction, and the particle size and the shape of the silver nanoparticles change regularly with the passage of time, specifically, see fig. 8, and the reaction time of 20-24 hours can obtain the tetrahedral and cubic silver nanoparticles with the proper particle size.
The inventor newly finds that the silicon wafer is hydroxylated and then ZnO is grown in the preparation process of the nanometer tower, which is the key for obtaining the nanometer tower, and the silicon wafer with rich hydroxyl on the surface is beneficial to the nucleation of the nanometer tower. The hydroxylation operation of silicon wafers is not different from the prior art, and a typical laboratory flow of hydroxylation of silicon wafers can be exemplified as follows:
ultrasonically cleaning a silicon wafer (2 cm multiplied by 2 cm) by using acetone, ethanol and distilled water for 10-15 min respectively, heating the cleaned silicon wafer in concentrated sulfuric acid at the temperature of 90-95 ℃ for 1-1.5 h, and then placing the silicon wafer in the distilled water: ammonia water: the volume ratio of hydrogen peroxide is 5: 1: 1 for 25-40 min, finally carrying out ultrasonic treatment in distilled water for 10min, and drying for later use.
In the preparation process of the nanometer tower, the formed growth solution of the ZnO nanometer tower can be obtained by mixing zinc chloride and ammonia water, the proportion of the zinc chloride and the ammonia water in the growth solution of the ZnO nanometer tower can influence the appearance of the ZnO nanometer tower, and in the invention, 1.48-5.56 ml of ammonia water is added relative to 1g of zinc chloride, so that the ZnO nanometer tower with the required appearance can be obtained.
An example of a typical laboratory preparation of a ZnO nanorod growth solution is as follows: dissolving 0.32-0.65 g of zinc chloride in 38ml of distilled water, stirring for 5min, adding 1.2-3 ml of ammonia water, and stirring for 8-15 min.
The ZnO nano-tower array is prepared on the silicon substrate by a chemical bath deposition method, the reaction temperature is controlled to be 85-95 ℃, and the reaction time is important to be 50-90 min. An example of a typical laboratory preparation of a ZnO nanocower growth process is as follows:
the hydroxylated silicon wafer was suspended in the growth solution using polyimide tape and the beaker sealed with a preservative film. And then placing the beaker in an oven, and heating for 50-90 min at 85-95 ℃. And after the reaction is finished, taking out the silicon wafer, ultrasonically cleaning the silicon wafer for 1min by using distilled water, and drying the silicon wafer by blowing to obtain the ZnO nano-tower array.
The assembly process is to use simple drop casting method to prepare the nano silver sol with the concentration of 2 multiplied by 10-4g/ml～2.5×10-3g/ml of silver colloid was drop-cast on the ZnO nano-tower array at a dropping ratio of 1cm per unit2The amount of the dropwise added silver sol is 0.2-0.6 ml, and the balance between the cost and the optimal enhancement effect can be obtained.
An example of a typical silver nanoparticle/ZnO nanotab SERS substrate assembly laboratory preparation is as follows:
cutting the ZnO nano-tower array into 0.5cm multiplied by 0.5cm, dripping 0.05ml of silver colloid on the ZnO nano-tower array by using an injector, drying at 38-55 ℃, and repeating the step for 2-3 times.
The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.
Example 1
Step A: preparation of silver sols consisting of tetrahedral and cubic silver nanoparticles. 0.0238g of silver nitrate and 0.155g of PVP were dissolved in 29ml of DMF solution and stirred for 30min to light yellow using magnetic force. The light yellow solution was transferred to a reaction kettle and heated to 170 ℃ for 22 h. After completion of the reaction, the autoclave was immediately taken out and cooled to room temperature in running water. The product was purified by repeated centrifugation with ethanol and finally dispersed in 20ml of ethanol. As shown in fig. 1 (a), the silver nanoparticles are mainly cubic and tetrahedral in shape, and the cubic content is larger, and the average diameter is about 64 nm. Both cubic and tetrahedral silver nanoparticles have vertex angles that can generate higher electric fields (i.e., hot spots) near these high curvature vertex angle regions under dipole plasmon resonance conditions, and thus have stronger SERS performance than spherical and quasi-spherical silver nanoparticles.
And a step B: and (3) preparing a hydroxylated silicon wafer. Ultrasonically cleaning a silicon wafer (2 cm multiplied by 2 cm) by using acetone, ethanol and distilled water for 15min respectively, heating the cleaned silicon wafer in concentrated sulfuric acid at 90 ℃ for 1h, and then placing the silicon wafer in the distilled water: ammonia water: the volume ratio of hydrogen peroxide is 5: 1: 1 for 30min, finally carrying out ultrasonic treatment in distilled water for 10min, and drying for later use.
And a step C: and (5) preparing a ZnO nano-tower array. In a 50ml beaker, 0.54g of zinc chloride is dissolved in 38ml of distilled water, stirred for 5min, then added with 2ml of ammonia water, and stirred for 10min to prepare the ZnO nano-tower growth solution. The hydroxylated silicon wafer was then suspended in the growth solution using 2mm wide polyimide tape and the beaker sealed with a preservative film. The beaker was then placed in an oven and heated at 95 ℃ for 75 min. And after the reaction is finished, taking out the silicon wafer, ultrasonically cleaning the silicon wafer for 1min by using distilled water, and drying the silicon wafer by blowing to obtain the ZnO nano-tower array. As shown in FIG. 2 (b), in a field emission Scanning Electron Microscope (SEM), the average diameter at the height of the nanometer column is about 700nm, and the length is about 3.2 μm. The tower body is a hexagonal prism, and the diameter of the tower tip prism is gradually reduced, so that a tower-shaped ladder is formed.
Step D: and (3) assembling the SERS substrate of the silver nano particle/ZnO nano tower. The ZnO nanorod array was first cut to 0.5cm x 0.5cm size, then 0.05ml of silver colloid was dropped on the ZnO nanorod array with a syringe and dried at 55 c, and finally this step was repeated 3 times with the SEM image shown in fig. 3. As shown in fig. 3 (a), silver nanoparticles are uniformly distributed on a ZnO nanocatalyst array, a large number of silver nanoparticles are present at both the side and top of the nanocatalyst, and the distance between the silver nanoparticles is very small, which results in strong local surface plasmon coupling between adjacent nanoparticles, i.e., silver nanoparticle gap hot spots. As shown in fig. 3 (b), it can be seen that a large amount of silver nanoparticles are stayed on the steps of the nanopillar tip, and thus the nanopillar tip will have a large number of hot spots.
The X-ray diffraction pattern of the obtained silver nanoparticle/ZnO nanorod substrate is shown in FIG. 4, and all diffraction peaks (excluding silicon peaks) are consistent with standard diffraction peaks (JCPDS card numbers 36-1451; JCPDS card numbers 04-0783) of hexagonal phase ZnO and cubic phase silver, which indicates the high purity and crystallinity of ZnO nanorods and silver nanoparticles. The strong and sharp diffraction peak at 34.4 ℃ indicates that the ZnO nano-tower array preferentially grows along the [0001] direction, and the nano-step decorated with silver nano-particles belongs to the (002) crystal face.
The SERS performance of this silver nanoparticle/ZnO nanopower substrate was evaluated using R6G as the detection object molecule. The test was performed on a xploid Plus raman spectrometer with a laser wavelength of 532nm and a laser power of 0.32 mW. As shown in fig. 5 (a), for 10-7～10-18Solutions of R6G in different concentrations of mol/L at 611, 771, 1125, 1189, 1308, 1360, 1508, 1573 and 1649 cm−1The characteristic peak of R6G is clearly observed, and the peak intensity of the characteristic peak is gradually reduced along with the reduction of the concentration. As shown in FIG. 5 (b), even if the concentration of the R6G solution is as low as 10-16、10-18A distinct characteristic peak of R6G was still observed at mol/L.
Comparative example 1
SERS performance comparison of silver nanoparticle/ZnO nanorod Array (AZR) substrate and silver nanoparticle/ZnO nanorod Array (AZT) substrate
To evaluate the raman activity of the AZT substrates, silver nanoparticle/ZnO nanorod Array (AZR) substrates were prepared for comparison with AZT array substrates.
The same operations as in example 1 were carried out except that the steps B and C in example 1 were changed to the following step C'. This is because the silicon wafer sputtered with the ZnO seed layer can assist the nucleation of nanorods, and the nanorods can be obtained when the ZnO is grown, specifically, the steps are as follows.
A step C':
magnetron sputtering a 50nm thick ZnO seed layer on a 2cm × 2cm Si substrate, and then suspending in 0.1M ZnCl using the same method as procedure C22ml of ammonia solution, and heated at 95 ℃ for 75 min. And after the reaction is finished, taking out the silicon wafer, ultrasonically cleaning the silicon wafer for 1min by using distilled water, and drying the silicon wafer by blowing to obtain the ZnO nanorod array.
Silver sol consisting of cubic and tetrahedral silver nanoparticles was then assembled onto the ZnO nanorod array by drop casting. Fig. 6 is an SEM image of the AZR array substrate, the ZnO nanorods are about 35 nm in diameter and about 2 μm in length, and it can be seen from the image that silver nanoparticles are uniformly distributed on the ZnO nanorod array, as shown in fig. 6 (a), and are trapped at a depth of about 100 nm at intervals between nanorods, as shown in fig. 6 (b), and thus, the silver nanoparticles on the ZnO nanorods correspond to a 2D distribution.
FIG. 7 shows that the dropping concentration of the AZT substrate and the AZR substrate is 10-7 M R6 SERS spectrum of 6G solution. The Raman characteristic peak of R6G can be clearly identified from the figure, wherein 611 cm-1、771 cm-1、1125 cm-1The characteristic peak is respectively related to the C-C-C in-plane bending vibration, the C-C-C out-of-plane bending vibration and the C-H plane bending vibration of the R6G molecule, and is 1189 cm-1、1360 cm-1、1508 cm-1And 1649 cm-1The characteristic peak at (a) is attributed to the C-C in-plane stretching vibration symmetry mode. The AZR array substrate has higher SERS activity due to strong Local Surface Plasmon Resonance (LSPR) generated at the vertex angles of cubic and tetrahedral silver nanoparticles and electron transfer resonance between the silver nanoparticles and ZnO. However, the intensity of all characteristic peaks of the AZT substrate was 1.5 times that of the AZR array. This is because, compared to nanorods having a diameter of about 35 nm, ZnO nanocolumns have a larger diameter (about 700 nm) and abundant nano steps, as shown in fig. 3, a large number of silver nanoparticles having a particle size of about 60 nm can be anchored on the surface of the nanocolumns, thereby realizing high-density 3D hot spot distribution, and particularly, the suitable distance between the nano steps can be ensured while retaining the silver nanoparticles, so that the nanocolumns have abundant raman hot spots, as shown in fig. 3 (D). In addition, when the solution to be measured is dripped on the nano-tower, the rough nano-steps can retain the solution on the nano-steps, and after the solution is evaporated, the R6G molecules are remained around the hot spot area. Furthermore, the slanted vertices of the nanocolumns facilitate more exposure of the silver nanoparticles at these locations to the incident laser light than ZnO nanorods without tips, thereby creating strong hot spots.
Comparative example 2
Influence of silver nanoparticle morphology on SERS performance of silver nanoparticle/ZnO nanocower array
In order to research the influence of the silver nanoparticle morphology on the SERS performance of the silver nanoparticle/ZnO nanocatalyst array, an AZT substrate assembled by spherical silver nanoparticles is prepared and compared with an AZT substrate assembled by cubic or tetrahedral silver nanoparticles.
The same operations as in example 1 were carried out except that the process A in example 1 was changed to the process A' described below
A': and changing the reaction time to 16h on the basis of the step A to obtain the nano silver sol.
Step A' to obtain a spherical nano silver sol shown in FIG. 8 (d), dropping the sol onto a ZnO nano tower array to prepare a substrate, and adding 1X 10 of the sol to the ZnO nano tower array-6 M to 1X 10-13 M different concentrations of R6G were dropped on the spherical silver nanoparticle/ZnO nanocatalyst substrate, and Raman signals were collected. The results are shown in FIG. 9, with the concentration of R6G varying from 1X 10-6 M is reduced to 1X 10-13 M, the intensity of Raman characteristic peak is gradually reduced, 1 × 10-13 M is the linear energy to distinguish the Raman characteristic peak of R6G, which shows that the detection limit of the spherical silver nano particle/ZnO nano tower substrate to R6G is 1 multiplied by 10-13 And M. Spherical silver nano particle/ZnO nano tower 1 x 10-7 The Raman peak intensity of the M concentration R6G is 3/4 of the peak intensity of the AZT substrate, and the detection limit is five orders of magnitude lower than that of the AZT substrate, which shows that the cubic and tetrahedral silver nanoparticles can increase the Raman activity of the AZT substrate.
It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments. The multiple schemes provided by the invention comprise basic schemes, are independent from each other and are not restricted with each other, but can be combined with each other under the condition of no conflict, so that multiple effects are realized together.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (7)
1. A surface enhanced Raman scattering substrate is characterized in that the surface enhanced Raman scattering substrate is formed by dispersing tetrahedral and cubic silver nano particles on a ZnO nano tower array,
the tetrahedral and cubic silver nanoparticles have an average diameter of 60 to 80nm,
the ZnO nanocrystallines are in a hexagonal prism shape, the diameter of the prism at the tip is gradually reduced to form a ladder-shaped appearance, the average length of the ZnO nanocrystallines is 2-4 mu m, and the average diameter of the height of the half body is 500-800 nm.
2. The surface-enhanced Raman scattering substrate according to claim 1, wherein the ZnO nanocolumn has an average length of 2.5 to 3.5 μm and an average diameter at a height of a half body of 650 to 750 nm.
3. A method for preparing a surface-enhanced raman scattering substrate, comprising:
dissolving inorganic silver salt and polyvinylpyrrolidone in an organic solvent, uniformly mixing, heating and reacting at 160-180 ℃ for 20-24 hours, cooling to room temperature, purifying a product, and dispersing the product in ethanol to obtain nano silver sol;
a nanometer tower preparation process, namely suspending the silicon wafer subjected to hydroxylation treatment in a ZnO nanometer tower growth solution formed by zinc chloride and ammonia water, sealing and heating to 85-95 ℃, carrying out reaction for 50-90 minutes to grow a ZnO nanometer tower array, taking out the silicon wafer after the reaction is finished, and cleaning and drying the silicon wafer to obtain the ZnO nanometer tower array; dissolving zinc chloride in distilled water, stirring for 5min, adding ammonia water, and stirring for 8-15 min to obtain a growth solution of the ZnO nano-tower, wherein 1.48-5.56 ml of ammonia water is added relative to 1g of zinc chloride;
and an assembling procedure, namely dripping the nano silver sol into a ZnO nano tower array, thereby assembling and obtaining the silver/zinc oxide nano tower surface enhanced Raman scattering substrate.
4. The method for preparing a surface-enhanced Raman scattering substrate according to claim 3, wherein silver nitrate is used as the inorganic silver salt, and N, N-dimethylformamide is used as the organic solvent.
5. The method for producing a surface-enhanced Raman scattering substrate according to claim 4, wherein a charge amount of the polyvinylpyrrolidone is 8 to 20 parts by mass with respect to 1 part by mass of the silver nitrate.
6. The method of claim 3, wherein the nano-silver sol is dispersed in ethanol to obtain a nano-silver sol having a concentration of 2X 10-4g/ml～2.5×10-3g/ml。
7. The method for producing a surface-enhanced Raman scattering substrate according to claim 3, wherein the assembling step is performed every 1cm2The amount of the nano silver sol dripped into the ZnO nano tower array is 0.2-0.6 ml.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010971591.2A CN112098390B (en) | 2020-09-16 | 2020-09-16 | Surface enhanced Raman scattering substrate and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010971591.2A CN112098390B (en) | 2020-09-16 | 2020-09-16 | Surface enhanced Raman scattering substrate and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112098390A CN112098390A (en) | 2020-12-18 |
| CN112098390B true CN112098390B (en) | 2021-12-14 |
Family
ID=73758652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010971591.2A Active CN112098390B (en) | 2020-09-16 | 2020-09-16 | Surface enhanced Raman scattering substrate and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112098390B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113933284B (en) * | 2021-10-12 | 2024-03-22 | 浙江工业大学 | Surface enhanced Raman rapid detection of natural anthraquinone dye in silk based on silver nano sol |
| CN115184339B (en) * | 2022-09-08 | 2022-12-23 | 海澳华(黑龙江)生物医药技术有限公司 | Method for rapidly detecting viruses based on portable Raman spectrometer |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1557717A (en) * | 2004-01-19 | 2004-12-29 | 上海交通大学 | Method for preparing zinc oxide nanometer material with orientation arrangement nano-towers |
| CN1958877A (en) * | 2006-10-19 | 2007-05-09 | 华东师范大学 | Periodic monocrystalline Nano structure of castellated ZnO, preparation method |
| WO2008127432A2 (en) * | 2006-11-21 | 2008-10-23 | California Institute Of Technology | Method of nonlinear harmonic holography |
| CN102156117A (en) * | 2011-03-22 | 2011-08-17 | 中国科学院长春应用化学研究所 | Substrate for surface enhanced Raman scattering and preparation method thereof |
| CN102706857A (en) * | 2012-07-02 | 2012-10-03 | 中国科学院合肥物质科学研究院 | Preparation method of multifunctional surface enhanced raman scattering (SERS) substrate |
| CN103030095A (en) * | 2011-09-30 | 2013-04-10 | 中国科学院合肥物质科学研究院 | Silver nanoparticle-modified zinc oxide nanorod array and preparation method and application thereof |
| CN103303967A (en) * | 2012-03-08 | 2013-09-18 | 国家纳米科学中心 | Tower-shaped layered zinc oxide nanometer rod, and preparation method and application thereof |
| KR101634332B1 (en) * | 2014-10-21 | 2016-07-01 | (주)플렉센스 | Sensor for spectroscopic analysis |
| CN109520995A (en) * | 2018-11-27 | 2019-03-26 | 首都师范大学 | A method of carrying out Surface enhanced Raman scattering detection |
| CN109612976A (en) * | 2018-12-24 | 2019-04-12 | 北华大学 | A kind of 3-dimensional multi-layered body structure surface enhancing Raman substrate and preparation method thereof |
| CN109916877A (en) * | 2019-03-25 | 2019-06-21 | 中国工程物理研究院材料研究所 | A kind of flexible surface enhancing Raman scattering substrate and its preparation, detection method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10376600B2 (en) * | 2016-03-03 | 2019-08-13 | Gholam A. Peyman | Early disease detection and therapy |
-
2020
- 2020-09-16 CN CN202010971591.2A patent/CN112098390B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1557717A (en) * | 2004-01-19 | 2004-12-29 | 上海交通大学 | Method for preparing zinc oxide nanometer material with orientation arrangement nano-towers |
| CN1958877A (en) * | 2006-10-19 | 2007-05-09 | 华东师范大学 | Periodic monocrystalline Nano structure of castellated ZnO, preparation method |
| WO2008127432A2 (en) * | 2006-11-21 | 2008-10-23 | California Institute Of Technology | Method of nonlinear harmonic holography |
| CN102156117A (en) * | 2011-03-22 | 2011-08-17 | 中国科学院长春应用化学研究所 | Substrate for surface enhanced Raman scattering and preparation method thereof |
| CN103030095A (en) * | 2011-09-30 | 2013-04-10 | 中国科学院合肥物质科学研究院 | Silver nanoparticle-modified zinc oxide nanorod array and preparation method and application thereof |
| CN103303967A (en) * | 2012-03-08 | 2013-09-18 | 国家纳米科学中心 | Tower-shaped layered zinc oxide nanometer rod, and preparation method and application thereof |
| CN102706857A (en) * | 2012-07-02 | 2012-10-03 | 中国科学院合肥物质科学研究院 | Preparation method of multifunctional surface enhanced raman scattering (SERS) substrate |
| KR101634332B1 (en) * | 2014-10-21 | 2016-07-01 | (주)플렉센스 | Sensor for spectroscopic analysis |
| CN109520995A (en) * | 2018-11-27 | 2019-03-26 | 首都师范大学 | A method of carrying out Surface enhanced Raman scattering detection |
| CN109612976A (en) * | 2018-12-24 | 2019-04-12 | 北华大学 | A kind of 3-dimensional multi-layered body structure surface enhancing Raman substrate and preparation method thereof |
| CN109916877A (en) * | 2019-03-25 | 2019-06-21 | 中国工程物理研究院材料研究所 | A kind of flexible surface enhancing Raman scattering substrate and its preparation, detection method |
Non-Patent Citations (8)
| Title |
|---|
| Aqueous solution fabrication of large-scale arrayed obelisk-like zinc oxide nanorods with high efficiency;Zhuo Wang et al.;《Journal of Solid State Chemistry》;20041231;第2144–2149页 * |
| Arrays of Cone-Shaped ZnO Nanorods Decorated with Ag Nanoparticles as 3D Surface-Enhanced Raman Scattering Substrates for Rapid Detection of Trace Polychlorinated Biphenyls;Haibin Tang et al.;《Advanced Functional Materials》;20120131;第218-224页 * |
| Growth of Tetrahedral Silver Nanocrystals in Aqueous Solution and Their SERS Enhancement;Ji Zhou et al.;《Langmuir》;20081231;第10407-10413页 * |
| Haibin Tang et al..Arrays of Cone-Shaped ZnO Nanorods Decorated with Ag Nanoparticles as 3D Surface-Enhanced Raman Scattering Substrates for Rapid Detection of Trace Polychlorinated Biphenyls.《Advanced Functional Materials》.2012, * |
| Oriented growth of ZnO nanostructures on different substrates via a hydrothermal method;Jinghai Yang et al.;《Journal of Alloys and Compounds》;20101231;第51-55页 * |
| Polyhedral Silver Nanocrystals with Distinct Scattering Signatures;Andrea Tao et al.;《Angew. Chem. Int. Ed》;20061231;第4597-4601页 * |
| Surface-Enhanced Raman Scattering: Comparison of Three Different Molecules on Single-Crystal Nanocubes and Nanospheres of Silver;Matthew Rycenga et al.;《J. Phys. Chem. A》;20091231;第3932-3939页 * |
| Tower-like structure of ZnO nanocolumns;Ping’an Hu et al.;《CHEM. COMMUN》;20031231;第1304–1305页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112098390A (en) | 2020-12-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gómez-Graña et al. | Au@ Ag nanoparticles: Halides stabilize {100} facets | |
| Huang et al. | Chiral guanosine 5′-monophosphate-capped gold nanoflowers: Controllable synthesis, characterization, surface-enhanced Raman scattering activity, cellular imaging and photothermal therapy | |
| Murph et al. | A possible oriented attachment growth mechanism for silver nanowire formation | |
| Zhu et al. | High-yield synthesis of uniform Ag nanowires with high aspect ratios by introducing the long-chain PVP in an improved polyol process | |
| Tang et al. | Silver nanodisks with tunable size by heat aging | |
| Li et al. | Rapid synthesis of broadband Ag@ TiO2 core–shell nanoparticles for solar energy conversion | |
| Sajanlal et al. | Mesoflowers: A new class of highly efficient surface-enhanced Raman active and infrared-absorbing materials | |
| Heli et al. | Synthesis and applications of nanoflowers | |
| CN112098390B (en) | Surface enhanced Raman scattering substrate and preparation method thereof | |
| Pienpinijtham et al. | Micrometer-sized gold nanoplates: starch-mediated photochemical reduction synthesis and possibility of application to tip-enhanced Raman scattering (TERS) | |
| Sun et al. | Morphology engineering of advanced materials | |
| Smith et al. | Environmental symmetry breaking promotes plasmon mode splitting in gold nanotriangles | |
| US8425653B2 (en) | Plasmon mediated photoinduced synthesis of silver triangular bipyramids | |
| Scarabelli et al. | Plate-like colloidal metal nanoparticles | |
| CN113649584B (en) | Growth method of laser-induced morphology-controllable gold or gold composite nanostructure and application thereof | |
| Chen et al. | Self-assembly of gold nanoparticles to silver microspheres as highly efficient 3D SERS substrates | |
| Liu et al. | Hydrothermal synthesis of gold nanoplates and their structure-dependent LSPR properties | |
| Zeng et al. | ZnO nanotower arrays decorated with cubic and tetrahedral shaped Ag-NPs as hybrid SERS-active substrates | |
| Kundu et al. | Photochemical synthesis of shape-selective palladium nanocubes in aqueous solution | |
| Liu et al. | Hydrothermal synthesis of gold polyhedral nanocrystals by varying surfactant concentration and their LSPR and SERS properties | |
| Pham et al. | Synthesis and in-depth study of the mechanism of silver nanoplate and nanodecahedra growth by LED irradiation for SERS application | |
| Jiang et al. | Low dimensional silver nanostructures: synthesis, growth mechanism, properties and applications | |
| Mingos | Historical Introduction to Gold Colloids, Clusters and Nanoparticles | |
| Tian et al. | Seedless, surfactantless photoreduction synthesis of silver nanoplates | |
| Zhang et al. | Hierarchically assembled NiCo@ SiO 2@ Ag magnetic core–shell microspheres as highly efficient and recyclable 3D SERS substrates |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |