WO2019179006A1 - 一种sers芯片的制备、保存及上样方法 - Google Patents

一种sers芯片的制备、保存及上样方法 Download PDF

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Publication number
WO2019179006A1
WO2019179006A1 PCT/CN2018/100342 CN2018100342W WO2019179006A1 WO 2019179006 A1 WO2019179006 A1 WO 2019179006A1 CN 2018100342 W CN2018100342 W CN 2018100342W WO 2019179006 A1 WO2019179006 A1 WO 2019179006A1
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sers
chip
sers chip
nano
substrate
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PCT/CN2018/100342
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English (en)
French (fr)
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郭清华
孙海龙
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苏州天际创新纳米技术有限公司
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    • 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
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y15/00—Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures

Definitions

  • the invention relates to a Surface-Enhanced Raman Scattering (SERS) technology, in particular to a method for preparing, preserving and loading a SERS chip.
  • SERS Surface-Enhanced Raman Scattering
  • SERS Surface-enhanced Raman
  • the signal enhancement capability of SERS stems from the unique nanostructures on the substrate.
  • the surface plasmon is excited, which greatly enhances the electromagnetic field around the object to be tested and increases the intensity of the Raman signal.
  • Different nanostructures produce different electromagnetic field enhancements, some of which can produce extreme electromagnetic field enhancements, which are called "hot spots.”
  • the hotspot area generally only accounts for about 1% of the overall location, but contributes 70% of the overall signal.
  • the formation and arrangement of control "hot spots” is the core of SERS chip preparation and even SERS technology application, and it is also a hot spot in the field of SERS research. However, only hotspots are not enough.
  • Target molecules must be present in the “hot spot” area in order to obtain relevant and effective information. Therefore, the preparation of samples in the "hot spot” area with target molecules should also be a focus of SERS technology application, but at present people pay little attention.
  • the "hot spot effect” is used to prepare the sample.
  • the former is generally a solid-phase chip, which can conveniently perform hot-spot arrangement, and can effectively control the uniformity and reproducibility of the SERS chip.
  • capillary action greatly reduces the molecular accessibility.
  • the invention aims to solve the problem that the SERS "hot spot” distribution controllable and the target molecule accessibility cannot be taken into consideration in the prior art.
  • a first aspect of the present invention provides a method and a storage system for storing a SERS chip.
  • a second aspect of the invention provides a method of preparing a SERS chip.
  • the third aspect provides a method of loading a SERS chip.
  • the method for preserving the SERS chip of the present invention is that the SERS chip comprises a solid phase chip substrate and a plurality of spaced apart nanostructure units disposed on the solid phase chip substrate, the nanostructure unit comprising one or more metal nanoparticles
  • the preservation method includes isolating the nanostructured unit of the freshly prepared SERS chip from air by a liquid solvent.
  • the preservation is performed by immersing the freshly prepared SERS chip in the liquid solvent.
  • the preservation is carried out by dropping the liquid solvent onto the SERS chip and forming a liquid seal layer on the nanostructure unit.
  • the surface of the SERS chip includes an active region for detecting sample molecules, the nanostructure unit is uniformly distributed in the active region, and a liquid seal for all the nanostructure units is realized by dropping the liquid solvent in the active region. .
  • the metal nanoparticles in the present invention form the nanostructure unit by aggregation, preferably by self-assembly methods.
  • the freshly prepared SERS chip of the present invention refers to a chip that has just been prepared and at least the nanostructured unit is still wet.
  • the nanostructure unit spacing distribution means that gaps are formed between adjacent two nanostructure units, rather than being joined together.
  • the liquid solvent in the present invention may be a liquid solvent which is inexpensive, non-toxic and volatile, and includes, but is not limited to, water, alcohol, ketone, ester.
  • the liquid solvent may be a single solvent or a mixed solvent.
  • the liquid solvent comprises at least one of water, ethanol, n-hexane, acetone, ethyl acetate, more preferably ultrapure water.
  • the liquid solvent includes, but is not limited to, a mixture of water and an alcohol, an alcohol and an alcohol.
  • the SERS chip is further frozen.
  • the storage time is preferably within one week.
  • the solid phase chip substrate may be those conventionally used in the art, and is not particularly limited, and may be, for example, a substrate having a flat surface or a substrate having a plurality of nano-protrusions formed on the surface.
  • the surface of the solid phase chip substrate is formed with a plurality of recesses, and a single of the nanostructure units are disposed inside a single of the recesses.
  • the solid phase chip substrate on which the depressed portion is formed can be prepared by an AAO stencil method, preferably a solid phase chip substrate having depressed portions of various specifications.
  • the specification of the recessed portion is defined by the contour shape of the recessed portion in the circumferential direction, the volume of the recessed portion, and the opening area of the recessed portion, and the circumferential contour shape of the two recessed portions, the volume of the recessed portion, and the opening of the recessed portion When any one of the three areas is different, it is regarded as two specifications.
  • the number of the depressed portions in the area per square centimeter is N, and the N depressed portions have at least N/10 kinds of specifications, and further preferably have at least N/8 kinds of specifications, more preferably at least N/6 specifications, most preferably at least N/3 specifications.
  • the depressed portions are arranged in an array on the surface of the substrate. Since the depressed portions have various specifications, the SERS chip exhibits a microscopic disordered morphology at a microscopic level, which breaks through the conventional understanding of an excellent SERS substrate. As mentioned above, since SERS substrate performance is closely related to structure, researchers have been working to obtain uniform nanostructures in the pursuit of repeatable SERS substrates. J.Phys.Chem.C 111,6720; ACS Appl.Mater.Interfaces 3 , 1033.
  • the inventors of the present invention have found in long-term research and in a large number of practices that energy resonances are highly prone to occur between structurally similar nanostructured units and will accumulate at the nanoparticle gaps ( The energy of the "hot spot” diverges, causing the SERS activity at the "hot spot” to drop significantly. It may be based on this factor that the SERS activity of some SERS substrates with too much structural similarity in the prior art is not prominent.
  • the inventor of the present invention can make the size and/or shape of the plurality of nano-structure units confined therein not exactly the same by making the specifications of the plurality of depressed portions different, and making the specifications of the depressed portions as much as possible.
  • nanostructure units of the same structure it is possible to avoid interaction between nanostructure units of the same structure, to eliminate its adverse effect on plasma localization, and to greatly enhance the SERS activity of the SERS unit as a SERS substrate.
  • nanostructure units (about 100 or more) in a large area (1 ⁇ m 2 ) have very close overall performance, and thus have macroscopic uniform characteristics, so that the SERS chip is very uniform, and thus The reliability of the SERS test results can be guaranteed, so that it can be applied to quantitative detection.
  • the density of the depressions on the solid phase chip substrate is from 10 8 to 10 10 /cm 2 .
  • the minimum separation distance between two adjacent depressed portions is 1 to 50 nm, further preferably 5 to 50 nm, and more preferably 10 to 30 nm.
  • the minimum separation distance between two adjacent recessed portions refers to a plurality of distances between an arbitrary point on the upper edge of one recessed portion and an arbitrary point on the upper edge of the adjacent one of the recessed portions. The minimum distance.
  • the depressed portion has a depth of 30 nm to 2 ⁇ m, and more preferably 30 to 150 nm.
  • the depth of the depressed portion refers to the maximum distance from the surface of the upper edge of the nano-recessed portion to the bottom surface of the depressed portion.
  • the concave portion is 0.0025 ⁇ m 2 ⁇ 16 ⁇ m 2.
  • the opening area of the depressed portion refers to the area of the surface surrounded by the upper edge of the depressed portion.
  • the depressed portion has a diameter of 50 nm to 4 ⁇ m, and more preferably 50 to 300 nm.
  • the diameter of the depressed portion refers to the largest distance among the plurality of distances between any two points on the upper edge of the depressed portion, and when the surface surrounded by the upper edge of the depressed portion is circular, the depressed portion
  • the diameter is the diameter of the circle; when the surface surrounded by the upper edge of the recess is square, the diameter of the recess is the diagonal of the square; when the surface surrounded by the upper edge of the recess is a triangle, the recess The diameter is the longest side of the triangle; when the surface surrounded by the upper edge of the recess is elliptical, the diameter of the recess is the long axis of the ellipse.
  • the present invention can achieve high density packing of nanostructure units by controlling the minimum distance between the recesses and/or the density of the recesses and/or the diameter of the nano-pits, which is advantageous for further enhancing the SERS effect. Further, the present invention can make the diameter of the depressed portion and the metal nanoparticles as small as possible. Preferably, the diameter of the nano-depression is 50-300 nm, and the diameter of the metal nanoparticles is 50-60 nm, so that the activity of the chip is better. , stability, uniformity and repeatability are better.
  • the depressed portion is obtained by ultraviolet etching, HF etching, laser etching, nanosphere printing or electrochemical method.
  • the plurality of recesses have various specifications by controlling the preparation parameters.
  • the substrate having a plurality of depressed portions on the surface may be prepared by a process such as nanosphere printing or electrochemical method, and specifically, but not limited to, the following document 2: J. Am. Chem. Soc. 127, 3710; .Commun.53, 7949.
  • Nanosphere printing is more controllable and can produce more pore structure parameters.
  • other nanostructure processing methods such as EBL, nanoimprint, etc.
  • these two methods have the advantages of high resolution, high operability and low cost, and are very suitable for the preparation of the SERS unit of the present invention.
  • the SERS chip of the present invention can be prepared in a variety of ways.
  • the nanoparticles by disposing the nanoparticles into a dispersion or the like and bringing them into contact with the substrate, the nanoparticles are allowed to enter the corresponding depressed portions, and the nanostructured units are formed by self-assembly or the like.
  • the preparation method is extremely simple and the preparation cost is extremely low.
  • this method does not require special treatment of the substrate and the nanodispersion, and has wide applicability (all reported nanopore structures, various nanosols are applicable), and thus various nanoparticle aggregate structures can be prepared. More importantly, this method enables high-throughput preparation of substrate structures, especially for commercial operations.
  • the preparation method may include depositing a plurality of nanoparticles in the dispersion into the plurality of depressions by gravity or the like, and self-assembling to form the plurality of nanostructure units.
  • the substrate or the metal nanoparticles may be surface-modified or hydrophobically modified, so that the nanoparticles are more likely to enter the depressed portion for aggregation.
  • the dispersion containing a plurality of nanoparticles may employ a nanosol.
  • the foregoing nanoparticles can be synthesized by a wet process, and the morphology and size thereof can also be conveniently regulated.
  • the corresponding processes and conditions can be referred to, but are not limited to, the following document 1: Angew.Chem.Int.Ed. 45, 3414.
  • the surface of the solid phase chip substrate is formed with a plurality of nano-protrusions, and the single nano-structure unit is disposed on a single upper surface of the nano-protrusion.
  • the nanoprotrusions comprise nanopillars, nanowires, nanoneedles or nanocones. It is preferred to use a nanocolumn having an aspect ratio of 8 to 12:1.
  • the nanoprotrusions in the present invention can be produced by a nanoprinting method.
  • the nanoprotrusion portion has a length of 50 nm to 4 ⁇ m, more preferably 50 to 300 nm, and a diameter of 30 nm to 2 ⁇ m, and more preferably 30 to 150 nm.
  • the metal nanoparticles comprise at least one of gold nanoparticles and silver nanoparticles.
  • the gap between adjacent metal nanoparticles in the nanostructure unit is 1 to 2 nm.
  • the gap between adjacent metal nanoparticles refers to the smallest distance among a plurality of distances of the surfaces of adjacent two metal nanoparticles.
  • At least two of said nanostructure units contain different amounts of metal nanoparticles; and/or wherein at least two of the nanostructure units have different shapes and/or sizes.
  • the nanostructure unit comprises from 3 to 6 metal nanoparticles to achieve a better SERS effect.
  • said SERS chip which is isolated from the air by said liquid solvent, is placed in a container and stored under closed conditions.
  • the preservation method in the present invention does not require a storage time, and may be temporarily stored, that is, the prepared fresh SERS chip is subjected to the storage method of the present invention for short-term storage, and then subjected to subsequent loading and measurement; or may be long-term storage, that is, The prepared fresh SERS chip is stored for a long time for convenient transportation and storage by the preservation method of the present invention, and the SERS chip is taken out from the liquid solvent for subsequent loading and measurement until it is used.
  • the present invention also provides a SERS chip product comprising a container provided with a receiving space, a SERS chip disposed in the receiving space, the SERS chip comprising a solid phase chip substrate and a plurality of disposed on the solid phase chip substrate A spaced apart nanostructure unit comprising one or more metal nanoparticles, the SERS chip product further comprising a liquid solvent for immersing the nanostructure unit.
  • one of said containers houses one or more of said SERS chips.
  • the specific design of the container can be varied and is not particularly limited.
  • the solid phase chip substrate may be those commonly used in the art, and is not particularly limited, and may be, for example, a substrate having a flat surface, or a substrate having a surface formed with nano-recessed portions, or a surface having nano-protrusions formed thereon. Substrate.
  • the definitions of the substrate, the nano depressed portion, the nano convex portion, and the like are the same as those in the above-described preservation method, and are not described herein again.
  • the invention also provides a preparation method of a SERS chip, comprising the following steps:
  • the fresh SERS chip comprising a solid phase chip substrate and a plurality of spaced apart nanostructure units disposed on the solid phase chip substrate, the nanostructure unit comprising one or more Metal nanoparticles;
  • the nanostructured unit is controlled to be in a wet state throughout the preparation process.
  • the surface potential of the metal nanoparticles is positive or negative.
  • the SERS chip is installed in a setting container, and after immersing the cleaned SERS chip as a whole or the nanostructure unit of the SERS chip in a liquid solvent, the container is closed.
  • the fresh SERS chip may be various solid phase chips prepared according to a known method, and is not particularly limited.
  • the nanostructured unit that controls the prepared chip is in a wet state, that is, it is stored in a liquid solvent.
  • the SERS chip is a chip prepared by a nanoparticle self-assembly method, and is stored in a liquid solvent when the chip is wet.
  • a method for preparing a SERS chip comprising: forming a nano-columnar structure on the solid phase chip substrate by nano-printing, the nano-columnar structure comprising a plurality of spaced-apart nano-columns, and then using the magnetron sputtering method in the plurality of nano-scales
  • the nanostructure unit is formed on the column, and the nano column is kept in a dry state to ensure that the nano column stands and does not aggregate.
  • the liquid is stored in a liquid solvent when the nano structure unit is still wet.
  • nanoparticle self-assembly method nano-printing method, and magnetron sputtering method are all known, and can be carried out with reference to conventional embodiments in the art.
  • the nanostructured units formed by the metal nanoparticles will have an ideal gap.
  • the accessibility of the "hot spot” is high, and the target molecule can enter the "hot spot" relatively freely.
  • the potential of the surface of the metal nanoparticle is determined by the ion enriched on the surface thereof, and may be introduced during the preparation of the metal nanoparticle or after the preparation is completed.
  • the aforementioned metal nanoparticles having a desired surface potential of a negative potential can be obtained according to the classical Frens method.
  • the concentration of the nanoparticles in the nanoparticle solution for assembly is controlled to be 1 ⁇ 10 9 to 3 ⁇ 10 9 /mL.
  • the purpose of the surface coupling modification described in the present invention is to improve the binding force of the metal nanoparticles on the substrate, including but not limited to coupling modification using a coupling agent, and modifying by other methods to make the metal nanometer.
  • the particles and the solid phase chip substrate can be easily coupled.
  • modification is carried out using a silane coupling agent, and silane coupling agents may be those which are common, such as, for example, 3-aminopropyltrimethyloxysilane.
  • the present invention also provides a method for loading a SERS chip, which uses a SERS chip or a SERS chip product saved according to the saver of the above SERS chip, and includes the following steps:
  • the step (1) may be carried out by naturally volatilizing or filtering paper to remove most of the liquid solvent on the SERS chip.
  • the present invention also provides a test method for a SERS chip, which performs SERS spectrum acquisition using a SERS chip obtained according to the above loading method.
  • the present invention has the following advantages compared with the prior art:
  • the invention facilitates the entry of the target molecules by using metal nanoparticles whose surface potentials are both positive or negative and by keeping the SERS chip before the target molecules are wetted, so that the "hot spot" on the SERS chip is in an open state.
  • the hot spot thus better controlling the balance of molecular accessibility and controllability of the "hot spot” distribution, so that the uniformity and reproducibility of the SERS chip is good and the low concentration of trace substances can be detected.
  • the invention can make the "hot spot” on the SERS chip open, and facilitate the target molecules to enter the "hot spot”; on the other hand, the life of the SERS chip can be greatly extended, thereby promoting the The development and application of SERS technology.
  • Figure 1 is a schematic view of the assembly of nanoparticles
  • FIG. 2 is a schematic diagram of the SERS chip drying sample preparation principle, wherein the left picture shows the SERS chip in a wet state, and the right picture shows the SERS chip after being dried after adsorbing the sample molecules;
  • Figure 3 is a TEM image of self-assembled gold nanoparticles on the surface of a silicon wafer
  • Figure 4 is a TEM image of self-assembled gold nanoparticles on the surface of the AAO template
  • FIG. 5 is a schematic view of a silicon nanocolumn SERS solid phase chip
  • FIG. 6 is a schematic diagram of a SERS chip sample preparation process
  • Figure 7 is an optical picture before and after drying of the SERS chip
  • FIG. 8 is a spectral image acquired in the third embodiment and the fourth embodiment, wherein the upper line is the line corresponding to the third embodiment, and the “hot spot” is tested when the hot spot is open; the lower line is the fourth embodiment. Line, when the "hot spot" is closed, the test is performed;
  • Figure 9 is a graph showing the change in activity of SERS chips over time under different storage conditions.
  • the nanoparticle self-assembly method is used to assemble the metal nanoparticles on the solid phase chip template; see Figure 2, the SERS chip is contacted with the sample molecules, and after the sample molecules enter the "hot spot", they are dried and finished loading. .
  • 1 and 2 are the SERS chip in a wet state.
  • the surface potential of the metal nanoparticles is positive or negative, there is electrostatic repulsion between the metal nanoparticles, and therefore, the metal nanoparticles
  • the inaccessibility is too close.
  • the accessibility of the "hot spot” is higher, that is, the "hot spot” is in an open state, so that the sample molecules enter relatively freely.
  • the "hot spot” shutdown of the chip caused by solution drying is an irreversible process. That is, once the chip is dried and then placed in a solvent to be wet, the "hot spot” cannot be opened again. Therefore, the chip can be dried after the final adsorption of the target molecule, and the chip must remain wet during the rest of the process.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • a cleaned silicon wafer (4 mm * 4 mm) or a substrate having a nano-recessed portion prepared by an AAO template method is activated by a concentrated sulfuric acid-oxygen solution method, and then immersed in 3-aminopropyltrimethyl In a dilute solution of oxysilane (APTMS) (19 ⁇ L of APTMS pure solution dissolved in 100 ml of ethanol) for 12 h, taken out, washed with ethanol, dried with N 2 gas, and baked at 110 ° C for 2 h.
  • APIMS oxysilane
  • FIG 3 and Figure 4 are respectively electron micrographs of SERS chips prepared by using this assembly method in silicon wafers and AAO templates. It can be seen from the figure that the size distribution of the nanoparticles is uniform and the particle arrangement is orderly.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • a nano-column with a 10:1 aspect ratio was prepared by nano-printing, and silver nanoparticles were sputtered at the top. During the preparation process, the nanocolumns are kept from standing up, and after the preparation, the silver nanoparticles are placed in a water-sealed state.
  • FIG. 5 is a schematic view showing the structure of a nano-pillar structure SERS chip.
  • Embodiment 3 is a diagrammatic representation of Embodiment 3
  • the SERS chip with nano-depressions prepared on the AAO template after the liquid seal was stored for 6 months in the first embodiment was taken out, face up, and the back side was placed on the filter paper, and most of the water layer was quickly dried by the filter paper.
  • the chip was placed in a previously prepared 1 mM pyridine ethanol solution, taken out after 10 minutes, and washed three times with ethanol. Once again, the back of the chip was placed on the filter paper. After most of the ethanol was blotted by the filter paper, the chip was placed on a glass slide to dry, and then subjected to SERS spectrum acquisition, and the obtained spectral image was the upper line in FIG.
  • FIG. 6 shows the flow of the SERS chip sample preparation process.
  • the Au nanoparticles are gradually fixed and enriched on the surface of the silicon substrate by the coupling of APTMS.
  • the surface potential is negative (Zeta potential is about - 36mV)
  • there is electrostatic repulsion between the nanoparticles so it can not be too close, forming a narrow gap; at this time, the "hot spot" has higher accessibility, making the target molecules more free.
  • the adsorption is saturated, most of the solvent on the surface of the chip is dried, leaving only a thin layer of solvent, which can greatly shorten the drying time of the chip.
  • the distance between the nanoparticles will be brought close to form a "hot spot” with high SERS activity.
  • the target molecule is already present at the "hot spot”, so the reduced molecular accessibility due to the "hot spot” gap becoming smaller (ie, closed) does not affect the final test effect.
  • the "hot spot” shutdown of the chip caused by solution drying is an irreversible process. That is, once the chip is dried and then placed in a solvent to be wet, the "hot spot” cannot be opened again. Therefore, the chip can be dried after the final adsorption of the target molecule, and the chip must remain wet during the rest of the process.
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • the SERS chip with nano-depressions prepared on the AAO template after the liquid seal was stored for 6 months in Example 1 was taken out, face up, and the back side was placed on the filter paper, and most of the water layer was dried by the filter paper and dried. .
  • the chip was placed in a previously prepared 1 mM pyridine ethanol solution, taken out after 10 minutes, and washed three times with ethanol. Once again, the back side of the chip was placed on the filter paper. After most of the ethanol was blotted dry by the filter paper, the chip was placed on a glass slide to dry, and then subjected to SERS spectral acquisition, and the obtained spectral image was the lower line in FIG.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • the SERS chips with nano-recessed portions prepared on the AAO template prepared in the same manner as in Example 1 were respectively stored in a water seal and air (preservative), and 5 pieces of SERS activity were tested each month. (Keep other conditions consistent), the chip stability characteristics obtained after the average result are shown in Figure 9 (normalized separately). It can be seen that the water-sealed chip has a shelf life of up to one year, and the chip stored in the air has a stable period of only half a year, and will gradually decay after half a year, and its activity is only 1/2 of the original after one year.
  • the water-sealed chip will continue to remain “hot spot” open, and its SERS activity has significant advantages over “hot spot” closed chips.
  • the storage method of the SERS chip recommended by the present invention is a water seal.

Abstract

一种SERS芯片的制备、保存及上样方法，SERS芯片包括固相芯片基底和设置在固相芯片基底上的多个间隔分布的纳米结构单元，纳米结构单元包括一个或多个金属纳米粒子，保存方法包括通过液态溶剂将新鲜制备的SERS芯片的纳米结构单元与空气隔绝，保存方法简单易行，且可大大延长固相SERS芯片的寿命。通过采用纳米粒子组装的方法并结合液封的方式储存，使得SERS芯片表面具有一层极薄的液体层，而液体层能够控制"热点"的开、关，从而能够较好地掌控分子可进入性及"热点"分布可控性的平衡，从而使得SERS芯片的均匀性和重现性好且能够检测低浓度的痕量物质。

Description

一种SERS芯片的制备、保存及上样方法 技术领域
本发明涉及表面增强拉曼(Surface-Enhanced Raman Scattering，SERS)技术，特别是一种SERS芯片的制备、保存及上样方法。
背景技术
表面增强拉曼(SERS)技术因其可达单分子检测的超高灵敏度而广受关注，其提供了目标分子相关的指纹特征，表达了诸如分子种类、分子取向、吸附方式等丰富的化学信息。SERS犹如放大镜，将微量信息进行极限放大后呈现在人们面前。因此，SERS作为表界面的重要研究工具，在材料科学、化学、表面催化、环境及食品科学及生物医药等领域具有巨大的应用前景。
SERS的信号增强能力源于基底上独特的纳米结构。当激光照在狭小的纳米结构时，会激发表面等离激元，大大增强了待测物周围的电磁场，提高其拉曼信号的强度。不同纳米结构产生的电磁场增强不同，其中一些特殊位置可产生极大的电磁场增强，这些位置被称为“热点”。热点区域一般仅占整体位置的1％左右，却贡献了整体信号的70％。控制“热点”的形成和排布是SERS芯片制备乃至SERS技术应用的核心，也是目前SERS领域研究的热点。然而，仅有热点是不够的，必须“热点”区域存在目标分子，才能获得相关的有效信息。因此制备样品时使“热点”区域存有目标分子，也应为SERS技术应用的一个重点，然而目前人们却甚少关注。
SERS应用中运用“热点效应”制样，通常有两种方式：一为预先制备“热点”，再将目标分子装入以获取其SERS光谱；另一种为吸附目标分子后，再进行“热点”制备。前者一般为固相芯片，可方便地进行热点排布，对于SERS芯片的均匀性和重现性均可有效掌控。然而，由于高SERS活性的“热点”往往间隙很小(～1nm)，毛细作用使其分子可进入性大大降低。因此，在检测低浓度的痕量物质时，即使吸附很长时间，也少有目标分子可到达“热点”区域，最终该物质的信号也较为微弱。后者往往为溶胶体系，在吸附了目标物质后，纳米粒子由于表面双电层的破坏，倾向于以热力学更稳定的聚集体方式存在。此种情形下，目标分子吸附较为容易，然而，此种“热点”制备方式随机性太高，形成的“热点”结构千差万别，因此结果的重现性不理想。如何在SERS“热点”分布可控的基础上，兼顾其目标分子可进入性，是一个两难的问题， 也是SERS技术发展的一个瓶颈。
发明内容
本发明旨在解决现有技术中SERS“热点”分布可控与目标分子可进入性不能兼顾的问题。
为解决以上问题，本发明第一方面提供一种SERS芯片的保存方法及保存系统。本发明第二方面提供一种SERS芯片的制备方法。第三方面提供一种SERS芯片的上样方法。
本发明的SERS芯片的保存方法为：SERS芯片包括固相芯片基底和设置在所述固相芯片基底上的多个间隔分布的纳米结构单元，所述纳米结构单元包括一个或多个金属纳米粒子，所述保存方法包括通过液态溶剂将新鲜制备的所述SERS芯片的所述纳米结构单元与空气隔离。
根据一种实施方式，通过将所述新鲜制备的SERS芯片浸没在所述液态溶剂中进行保存。
根据另一种实施方式，通过将所述液态溶剂滴加在所述SERS芯片上并在所述纳米结构单元上形成液封层进行保存。所述SERS芯片表面包括用于检测样品分子的活性区域，所述纳米结构单元均匀分布在活性区域内，通过将所述液态溶剂滴加在所述活性区域内实现对所有纳米结构单元的液封。
本发明中的金属纳米粒子通过聚集形成所述纳米结构单元，优选通过自组装方法进行聚集。
本发明中新鲜制备的SERS芯片指的是刚制备完成且至少所述纳米结构单元尚处于湿润状态的芯片。
本发明中，纳米结构单元间隔分布指的是相邻两个纳米结构单元之间形成有间隙，而非连接在一起。
本发明中的液态溶剂可以采用便宜无毒且易挥发的液态溶剂，所述液态溶剂包括但不限于水、醇、酮、酯。所述液态溶剂可以使单一溶剂也可以是混合溶剂。优选地，所述液态溶剂包括水、乙醇、正己烷、丙酮、乙酸乙酯中的至少一种，更优选为超纯水。优选地，所述液态溶剂包括但不限于水与醇、醇与醇的混合物。
根据一种优选实施方式，将所述液态溶剂滴加在所述活性区域内实现对所有纳米结构单元的液封后，进一步将所述SERS芯片进行冰冻保存。保存时间优选为一周之内。
本发明中，固相芯片基底可以是本领域常用的那些，没有特别限制，例如可以是具有平整表面的基底，或者是表面形成有多个纳米凸起部的基底。
根据一种优选实施方式，所述的固相芯片基底的表面形成有多个凹陷部，单个所述纳米结构单元设置在单个所述凹陷部内部。
根据该实施方式，形成有凹陷部的固相芯片基底可以通过AAO模版法制备，优选采用具有多种规格的凹陷部的固相芯片基底。
其中，凹陷部的规格由所述凹陷部周向的轮廓形状、凹陷部的体积、凹陷部的开口面积限定，当二个凹陷部的周向的轮廓形状、凹陷部的体积、凹陷部的开口面积三个中的任意一个不同时，视为二种规格。
进一步优选地，设每平方厘米的面积内所述凹陷部的个数为N个，该N个凹陷部至少具有N/10种规格，再进一步优选至少具有N/8种规格，更优选至少具有N/6种规格，最优选至少N/3种规格。
本发明，优选地，凹陷部在基底表面上阵列排布，由于凹陷部具有多种规格，使得SERS芯片在微观下呈现出微观无序的形态，这突破了人们对优秀SERS基底的常规认识。前文可知，由于SERS基底性能与结构密切相关，因此研究者在追求可重复的SERS基底时，一贯致力于获得均一的纳米结构J.Phys.Chem.C 111,6720；ACS Appl.Mater.Interfaces 3,1033。诚然，均一的纳米结构可确保获得良好的重现性，但本案发明人在长期研究和大量实践中发现，结构相似的纳米结构单元之间极易发生能量共振，将聚集在纳米粒子间隙处(“热点”)的能量发散出去，导致“热点”处的SERS活性大大下降。可能正是基于此因素，使得现有技术中一些结构相似性太高的SERS基底的SERS活性并不突出。本案发明人通过使多个凹陷部的规格有所差异，并尽量使凹陷部的规格尽可能多，可以使被限制于其中的多个纳米结构单元的尺寸和/或形状也不完全相同，如此可以避免因相同结构的纳米结构单元之间产生相互作用，消除其对于等离子体局域化的不利影响，大幅增强SERS单元作为SERS基底应用时的SERS活性。另一方面，从统计角度，大面积范围内(1μm 2)的纳米结构单元(约100个或更多)总体性能却十分接近，因而具有宏观均一的特征，使得所述SERS芯片十分均匀，进而可以保障SERS测试结果的可靠性，使之可以很好的应用于定量检测。
优选地，凹陷部在固相芯片基底上的分布密度为10 8～10 10个/cm 2。
优选地，相邻二个所述凹陷部之间的最小间隔距离为1～50nm，进一步优 选为5～50nm，更优选为10～30nm。
本发明中，相邻二个凹陷部之间的最小间隔距离指的是一个凹陷部的上边缘上的任意点与相邻的一个凹陷部的上边缘上的任意点之间的多个距离中最小的距离。
优选地，所述凹陷部的深度为30nm～2μm，进一步优选为30～150nm。
本发明中，凹陷部的深度指的是纳米凹陷部的上边缘所在面至凹陷部底面的最大距离。
优选地，所述凹陷部的开口面积为0.0025μm 2～16μm 2。
本发明中，凹陷部的开口面积指的是凹陷部上边缘所围成的面的面积。
优选地，所述的凹陷部的直径为50nm～4μm，进一步优选为50～300nm。
本发明中，凹陷部的直径指的是凹陷部上边缘上的任意两点之间的多个距离中的最大的距离，当凹陷部的上边缘围成的面呈圆形时，凹陷部的直径为该圆形的直径；当凹陷部的上边缘围成的面呈方形时，凹陷部的直径为该方形的对角线；当凹陷部的上边缘围成的面为三角形时，凹陷部的直径为该三角形的最长边；当凹陷部的上边缘围成的面呈椭圆形时，凹陷部的直径为该椭圆的长轴。
本发明通过控制凹陷部之间的最小距离和/或凹陷部的密度和/或纳米凹陷部的直径，可以实现纳米结构单元的高密度堆积，利于进一步加强SERS效应。进一步的，本发明可以做到凹陷部和金属纳米粒子的直径尽可能小，优选地，纳米凹陷部的直径为50～300nm，金属纳米粒子的直径为50～60nm，从而使得芯片的活性更好，稳定性、均匀性和可重复性更佳。
优选地，所述的凹陷部通过紫外刻蚀、HF刻蚀、激光刻蚀、纳米球印刷术或电化学法制得。
进一步优选地，通过控制制备参数使所述多个凹陷部具有多种规格。
例如，前述的表面具有多个凹陷部的基材可以通过纳米球印刷术或电化学法等工艺制备，具体可参考但不限于如下文献2：J.Am.Chem.Soc.127，3710；Chem.Commun.53,7949。
其中，电化学法制备具有纳米孔洞的基材的过程是十分容易的，并已商业化(例如AAO模板)。而纳米球印刷相对可控性更强，可制备更多的孔道结构参数。这两种方法相对其它纳米结构加工方法(例如EBL、纳米压印等)，具有分辨率高，操作性强，成本低廉的优势，十分适合本发明所述SERS单元的 制备。
本发明中SERS芯片可以通过多种方式制备。
例如，本发明通过将纳米粒子调配为分散液等形式，并使之与基材接触，进而使纳米粒子进入相应的凹陷部，并通过自组装等形式聚集形成纳米结构单元。该制备方法极其简单，制备成本极其低廉。且此方法无需对基材和纳米分散液进行特殊处理，适用性广(所有已报导的纳米孔道结构，各种纳米溶胶均适用)，因此可以制备多种纳米粒子聚集体结构。更重要的是，此方法可高通量的制备基底结构，尤其适合商业化运作。
进一步地，所述的制备方法可以包括：通过重力作用等使所述分散液中的多个纳米粒子沉积到所述多个凹陷部内，并自组装形成所述多个纳米结构单元。
更进一步地，可以对基材或者金属纳米粒子进行表面改性或疏水修饰，从而更利于纳米粒子进入到凹陷部中进行聚集。
进一步地，所述包含多个纳米粒子的分散液可以采用纳米溶胶。
例如，前述的纳米粒子可以通过湿法工艺合成，其形貌、尺寸亦可以是被方便的调控的，相应的工艺过程及条件可以参考但不限于如下文献1：Angew.Chem.Int.Ed.45,3414。
根据另一种优选实施方式，所述的固相芯片基底的表面形成有多个纳米凸起部，单个所述纳米结构单元设置在单个所述纳米凸起部上表面。
优选地，所述纳米凸起部包括纳米柱、纳米线、纳米针或纳米锥形。优选采用长径比为8～12:1的纳米柱。
本发明中的纳米凸起部可以通过纳米印刷方法制得。
优选地，所述纳米凸起部的长度为50nm～4μm，进一步优选为50～300nm，直径为30nm～2μm，进一步优选为30～150nm。
优选地，所述金属纳米粒子包括金纳米粒子、银纳米粒子中的至少一种。
优选地，所述的纳米结构单元中相邻金属纳米粒子之间的间隙为1～2nm。
本发明中，相邻金属纳米粒子之间的间隙指的是相邻两个金属纳米粒子表面的多个距离中最小的距离。
优选地，其中至少两个所述的纳米结构单元所含金属纳米粒子的数量不同；和/或，其中至少两个纳米结构单元的形状和/或尺寸不同。
优选地，所述的纳米结构单元包含3～6个金属纳米粒子，以取得更为良好 的SERS效应。
根据一个优选方案，将通过所述的液态溶剂使所述的纳米结构单元与空气隔离的所述的SERS芯片置于容器中，在封闭条件下进行保存。
本发明中的保存方法对保存时间没有要求，可以是临时存放，即制备好的新鲜SERS芯片采用本发明的保存方法短时间存放后即进行后续的上样和测定；也可以是长期保存，即制备好的新鲜SERS芯片为了方便输送和储存采用本发明的保存方法进行长时间保存，直至需要使用时，才从液态溶剂中取出SERS芯片进行后续的上样和测定。
本发明还提供一种SERS芯片产品，包括设有容纳空间的容器、设置在所述容纳空间内的SERS芯片，所述SERS芯片包括固相芯片基底和设置在所述固相芯片基底上的多个间隔分布的纳米结构单元，所述纳米结构单元包括一个或多个金属纳米粒子，所述的SERS芯片产品还包括用于浸没所述纳米结构单元的液态溶剂。
优选地，一个所述的容器内装有一个或多个所述的SERS芯片。容器的具体设计可以多种多样，没有特别限制。
本发明中，固相芯片基底可以是本领域常用的那些，没有特别限制，例如可以是具有平整表面的基底，或者是表面形成有纳米凹陷部的基底，或者是表面形成有纳米凸起部的基底。
其中，关于基底，纳米凹陷部，纳米凸起部等的限定与上述保存方法中的相同，此处不再赘述。
本发明还提供一种SERS芯片的制备方法，包括如下步骤：
(1)制备新鲜的SERS芯片，所述的新鲜SERS芯片包括固相芯片基底和设置在所述固相芯片基底上的多个间隔分布的纳米结构单元，所述纳米结构单元包括一个或多个金属纳米粒子；
(2)对步骤(1)制得的SERS芯片进行清洗；
(3)将清洗后的SERS芯片整体或者SERS芯片的纳米结构单元浸没在液态溶剂中；
在整个制备过程中，控制所述的纳米结构单元处于润湿状态。
优选地，所述的金属纳米粒子的表面电势均为正或均为负。
优选地，步骤(3)中，所述的SERS芯片装设于设定容器中，在将清洗后的SERS芯片整体或者SERS芯片的纳米结构单元浸没在液态溶剂中后，将 容器封闭。
根据本发明，所述新鲜SERS芯片可以是按照已知的方法制备的各种固相芯片，没有特别限制。优选地，控制制备好的芯片的纳米结构单元处于湿润状态时，即用液态溶剂液封保存。例如，SERS芯片是通过纳米粒子自组装方法制备的芯片，在芯片处于湿润状态时放入液态溶剂进行保存。或者SERS芯片的制备方法包括：通过纳米印刷在所述固相芯片基底上形成纳米柱状结构，纳米柱状结构包括多个间隔分布的纳米柱，然后通过磁控溅射方法在所述的多个纳米柱上形成纳米结构单元，在制备纳米柱时保持干燥状态从而保证纳米柱矗立不聚集，溅射好纳米结构单元后，在纳米结构单元还处于湿润状态时放入液态溶剂进行保存。
上述的纳米粒子自组装方法、纳米印刷方法以及磁控溅射方法均是已知的，可以参照本领域惯常的实施方式来进行。其中优选地，需要在过程中确保金属纳米粒子表面的电势均为正或均为负，从而使得在湿润状态下，金属纳米粒子表面的电势的存在使得金属纳米粒子之间存在静电排斥作用，因此，由金属纳米粒子形成的纳米结构单元之间会具有理想的间隙，此时，“热点”的可进入性较高，目标分子能够较为自由的进入“热点”。进一步地，金属纳米粒子表面的电势由其表面富集的离子决定，可以是在金属纳米粒子制备过程中引入或是制备完成后后期引入。例如，按照经典的Frens方法可以获得前述期望的表面电势为负电势的金属纳米粒子。
此外，还优选地，控制组装用的纳米粒子溶液中的纳米粒子的浓度为1×10 9～3×10 9个/mL。
此外，还优选地，先依次对所述的固相芯片基底进行活化与表面偶联改性，然后在改性后的固相芯片基底上形成纳米结构单元。
本发明中所述的表面偶联改性的目的在于提高金属纳米粒子在基底上的结合力，包括但不局限于采用偶联剂进行偶联改性，采用其他方法进行改性从而使金属纳米粒子与固相芯片基底容易进行偶联也可。作为本发明的一个优选方案，采用硅烷偶联剂进行改性，硅烷偶联剂可以是常见的那些，具体例如3-氨丙基三甲基氧基硅烷等。
本发明还提供一种SERS芯片的上样方法，该方法使用按照上述SERS芯片的保存方保存的SERS芯片或上述SERS芯片产品，并包括如下步骤：
(1)、待SERS芯片上的大部分液态溶剂干后，放入样品溶液中，浸渍设 定时间使样品分子吸附到SERS芯片上，整个过程中保持所述的SERS芯片的纳米结构单元湿润；
(2)、取出吸附了样品分子的SERS芯片，洗涤，干燥。
本发明中，步骤(1)可以采用自然挥发或者用滤纸吸等方法使SERS芯片上的大部分液态溶剂干掉。
本发明还提供一种SERS芯片的测试方法，利用按照上述上样方法得到的SERS芯片进行SERS光谱采集。
由于以上技术方案的实施，本发明与现有技术相比具有如下优点：
本发明通过采用表面电势均为正或均为负的金属纳米粒子以及通过使吸附好目标分子前的SERS芯片保持湿润，从而使得SERS芯片上的“热点”处于开的状态，便于目标分子进入“热点”，从而较好地掌控了分子可进入性及“热点”分布可控性的平衡，从而使得SERS芯片的均匀性和重现性好且能够检测低浓度的痕量物质。
本发明通过将SERS芯片在液态溶剂中保存，一方面可以使SERS芯片上的“热点”处于开的状态，便于目标分子进入“热点”；另一方面可以大大延长SERS芯片的寿命，从而推动了SERS技术的发展应用。
附图说明
图1为纳米粒子组装示意图；
图2为SERS芯片干燥制样原理示意图，其中，左图为湿润状态的SERS芯片，右图为吸附了样品分子后干燥后的SERS芯片；
图3为在硅片表面自组装金纳米粒子的TEM图；
图4为在AAO模板表面自组装金纳米粒子的TEM图；
图5为硅纳米柱SERS固相芯片的示意图；
图6为SERS芯片制样流程示意图；
图7为SERS芯片干燥前后的光学图片；
图8为实施例三和实施例四采集的光谱图像，其中，上面的谱线为实施例三对应的谱线，此时“热点”处于开时进行测试；下面的谱线为实施例四对应的谱线，此时“热点”处于闭时进行测试；
图9为不同保存条件下SERS芯片活性随时间变化图。
具体实施方式
本发明的原理：
参见图1，采用纳米粒子自组装的方法将金属纳米粒子组装在固相芯片模板上；参见图2，将SERS芯片与样品分子接触，待样品分子进入“热点”后，进行干燥，完成上样。
其中，图1以及图2的左图为湿润状态的SERS芯片，此时，由于金属纳米粒子表面电势均为正或均为负，金属纳米粒子之间存在静电排斥作用，因此，金属纳米粒子之间无法靠的太近，此时，“热点”的可进入性较高，即，“热点”处于开的状态，使得样品分子进入较为自由。
当吸附饱和后，芯片干燥后，由于纳米金属表面双电层破坏以及溶剂挥发效应，将拉近金属纳米粒子之间的距离，形成高SERS活性的“热点”。此时，“热点”处已有目标分子，参见图2的右图，因此由于“热点”间隙变小(即关闭)而减小的分子可进入性并不影响最终的测试效果。
这里需要指出的是，溶液干燥导致的芯片“热点”关闭是不可逆过程。即一旦芯片干燥后，再将其放入溶剂中湿润，也不能再次将“热点”打开。因此，除最终吸附完目标分子后可晾干芯片，其余过程中芯片须保持湿润状态。
为了使本发明更加清楚，结合附图和实施例对本发明做进一步说明，应当理解，本实施例并不用于限定本发明的保护范围。本发明中未详细描述的方法和条件为本领域的常规条件。
实施例一：
(1)采用经典Frens方法合成金纳米粒子：在强烈搅拌下，将0.75mL 1％(w/v％)柠檬酸钠加入到100mL沸腾的0.01％(w/v％)氯金酸溶液中，搅拌下继续回流15min，自然冷却至室温，可获得粒径为40nm的Au纳米粒子，并进行稀释得到浓度为2×10 9个/mL的Au纳米粒子稀溶液。
(2)将洗净的硅片(4mm*4mm)或采用AAO模板法制备的具有纳米凹陷部的基底采用浓硫酸-双氧水溶液法进行活化，随后将其浸泡在3-氨丙基三甲基氧基硅烷(APTMS)的稀溶液中(19μL APTMS纯溶液溶于100ml乙醇中)12h，取出，用乙醇清洗，N 2气吹干，在110℃下烘2h。随后将其浸泡在步骤(1)制得40nm Au纳米粒子稀溶液中(估计其浓度为2×10 9个/mL)2h，取出，用超纯水清洗后放入水中保存。
图3、图4分别为运用此种组装方法在硅片和AAO模板中制备的SERS芯片电镜图。从图中可以看出，纳米粒子尺寸分布均匀，粒子排布规则有序。
实施例二：
运用纳米印刷制备长径比为10：1的纳米柱，并在其顶端溅射银纳米粒子。制备过程中保持纳米柱矗立不聚集，制备完毕后趁银纳米粒子处于湿润状态时将芯片放入水中液封保存。
图5为纳米柱结构SERS芯片结构示意图。
实施例三：
将实施例一中液封保存6个月后的在AAO模板上制备的具有纳米凹陷部的SERS芯片取出，正面朝上，背面放于滤纸上，待大部分水层被滤纸吸干后，迅速将芯片放入事先准备好的1mM吡啶乙醇溶液中，10min后取出，用乙醇冲洗3次。再一次将芯片背面放于滤纸上，待大部分乙醇被滤纸吸干后，将芯片放于载玻片上晾干，随后进行SERS光谱采集，所得光谱图像为图8中上面的一条谱线。
图6为SERS芯片制样流程示意。在进行纳米粒子自组装时，Au纳米粒子通过APTMS的偶联作用，逐渐在硅片基底表面固定并富集，然而，由于纳米粒子表面富含柠檬酸根，其表面电势为负(Zeta电位约-36mV)，纳米粒子之间存在静电排斥作用，因此并不能距离太近，形成狭小的间隙；此时，“热点”的可进入性较高，使得目标分子进入较为自由。当吸附饱和后，将芯片表面大部分溶剂吸干，仅留下薄薄一层溶剂层，可大大缩短芯片晾干时间。芯片干燥后，由于表面双电层破坏以及溶剂挥发效应，将拉近纳米粒子之间的距离，形成高SERS活性的“热点”。此时，“热点”处已有目标分子，因此由于“热点”间隙变小(即关闭)而减小的分子可进入性并不影响最终的测试效果。这里需要指出的是，溶液干燥导致的芯片“热点”关闭是不可逆过程。即一旦芯片干燥后，再将其放入溶剂中湿润，也不能再次将“热点”打开。因此，除最终吸附完目标分子后可晾干芯片，其余过程中芯片必须保持湿润状态。
芯片“热点”是否关闭有一个较好的判断方法，如图7所示，一旦“热点”关闭，则由间隙改变引起的纳米粒子表面SPR变化会使得芯片颜色发生极大的改变。红色的芯片代表“热点”开放，而黑色的芯片代表“热点”已经闭合。
实施例四：
将实施例一中液封保存6个月后的在AAO模板上制备的具有纳米凹陷部的SERS芯片取出，正面朝上，背面放于滤纸上，待大部分水层被滤纸吸干后晾干。将芯片放入事先准备好的1mM吡啶乙醇溶液中，10min后取出，用乙醇冲洗3次。再一次将芯片背面放于滤纸上，待大部分乙醇被滤纸吸干后，将芯片放于载玻片上晾干，随后进行SERS光谱采集，所得光谱图像为图8中的下面一条谱线。
从图8的两个光谱对比可以看出，在保持其他条件相同的情况下，开放的“热点”能吸附更多的目标分子，因此获得的SERS信号10倍好于关闭的“热点”。此实验明确的表明了保持“热点”开放对SERS检测具有重大的意义。
实施例五：
将按照实施例一的方法制备的同一批次在AAO模板上制备的具有纳米凹陷部的SERS芯片分别以水封和空气中放置(保干器)保存，每月分别取5片测试其SERS活性(保持其他条件一致)，平均结果后获得的芯片稳定性特征如图9所示(分别归一化)。可以看出，水封的芯片保质期长达1年，而放入空气中保存的芯片仅有半年的活性稳定期，半年之后将逐渐衰减，1年后其活性仅为起初的1/2。
相比水封，空气中氧气会对贵金属表面(如银)进行氧化刻蚀，影响其SERS稳定性。此外，长期储存使得空气中的有机污染物吸附于SERS芯片表面，引入污染，使其性能下降。因此，水封相对空气储存较为有效。
更重要的是，如上文所述，水封的芯片将持续保持“热点”开放状态，其SERS活性相比“热点”闭合的芯片具有明显的优势。
综上，本发明推荐的SERS芯片存储方式为水封。

Claims (19)

  1. 一种SERS芯片的保存方法，其特征在于：SERS芯片包括固相芯片基底和设置在所述固相芯片基底上的多个间隔分布的纳米结构单元，所述纳米结构单元包括一个或多个金属纳米粒子，所述保存方法包括通过液态溶剂将新鲜制备的所述SERS芯片的所述纳米结构单元与空气隔离。
  2. 根据权利要求1所述的SERS芯片的保存方法，其特征在于：通过将所述新鲜制备的SERS芯片浸没在所述液态溶剂中进行保存。
  3. 根据权利要求1所述的SERS芯片的保存方法，其特征在于：通过将所述液态溶剂滴加在所述SERS芯片上并在所述纳米结构单元上形成液封层进行保存。
  4. 根据权利要求1至3中任一项所述的SERS芯片的保存方法，其特征在于：所述液态溶剂包括水、乙醇、正己烷、丙酮、乙酸乙酯中的至少一种。
  5. 根据权利要求1至3中任一项所述的SERS芯片的保存方法，其特征在于：所述的固相芯片基底的表面形成有多个凹陷部，单个所述纳米结构单元设置在单个所述凹陷部内部。
  6. 根据权利要求5所述的SERS芯片的保存方法，其特征在于：所述凹陷部的直径为50nm～4μm，深度为30nm～2μm。
  7. 根据权利要求1至3中任一项所述的SERS芯片的保存方法，其特征在于：所述的固相芯片基底的表面形成有多个纳米凸起部，单个所述纳米结构单元设置在单个所述纳米凸起部上表面。
  8. 根据权利要求7所述的SERS芯片的保存方法，其特征在于：所述纳米凸起部包括纳米柱、纳米线、纳米针或纳米锥形。
  9. 根据权利要求1至3中任一项所述的SERS芯片的保存方法，其特征在于：所述金属纳米粒子包括金纳米粒子、银纳米粒子中的至少一种。
  10. 根据权利要求1至3中任一项所述的SERS芯片的保存方法，其特征在于：将通过所述的液态溶剂使所述的纳米结构单元与空气隔离的所述的SERS芯片置于容器中，在封闭条件下进行保存。
  11. 一种SERS芯片产品，包括设有容纳空间的容器、设置在所述容纳空间内的SERS芯片，所述SERS芯片包括固相芯片基底和设置在所述固相芯片基底上的多个间隔分布的纳米结构单元，所述纳米结构单元包括一个或多个金属纳米粒子，其特征在于：所述的SERS芯片产品还包括用于浸没所述纳米结构单元的液态溶剂。
  12. 根据权利要求11所述的SERS芯片产品，其特征在于：一个所述的容器内装有一个或多个所述的SERS芯片。
  13. 根据权利要求11或12所述的SERS芯片产品，其特征在于：所述的固相芯片基底的表面形成有多个凹陷部，单个所述纳米结构单元设置在单个所述凹陷部内部。
  14. 根据权利要求13所述的SERS芯片产品，其特征在于：所述凹陷部的直径为50nm～4μm，深度为30nm～2μm。
  15. 根据权利要求11或12所述的SERS芯片产品，其特征在于：所述的固相芯片基底的表面形成有多个纳米凸起部，单个所述纳米结构单元设置在单个所述纳米凸起部上表面。
  16. 根据权利要求15所述的SERS芯片产品，其特征在于：所述纳米凸起部包括纳米柱、纳米线、纳米针或纳米锥形。
  17. 根据权利要求11或12所述的SERS芯片产品，其特征在于：所述金属纳米粒子包括金纳米粒子、银纳米粒子中的至少一种。
  18. 一种SERS芯片的上样方法，其特征在于：该方法使用按照权利要求1～10中任一项权利要求所述的SERS芯片的保存方保存的SERS芯片或权利要求11～17中任一项权利要求所述的SERS芯片产品，并包括如下步骤：
    (1)、待SERS芯片上的大部分液态溶剂干后，放入样品溶液中，浸渍设定时间使样品分子吸附到SERS芯片上，整个过程中保持所述的SERS芯片的纳米结构单元湿润；
    (2)、取出吸附了样品分子的SERS芯片，洗涤，干燥。
  19. 一种SERS芯片的测试方法，其特征在于：利用按照权利要求18所述的上样方法得到的SERS芯片进行SERS光谱采集。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102910573A (zh) * 2012-10-24 2013-02-06 吉林大学 可揭除保护层的多级金属微纳结构阵列sers活性基底的制备方法
CN103267753A (zh) * 2013-01-15 2013-08-28 江苏大学 一种半导体Fe2O3薄膜型表面拉曼散射基底的制备方法
CN103293142A (zh) * 2013-05-09 2013-09-11 北京大学 一种柔性的表面增强拉曼光谱基底及其制备方法
CN103776812A (zh) * 2012-10-17 2014-05-07 胡建明 表面增强拉曼基底的制备方法
WO2015009239A1 (en) * 2013-07-17 2015-01-22 Nanyang Technological University Sers-active device and method of manufacturing the device
CN106290296A (zh) * 2016-07-27 2017-01-04 深圳大学 一种基于金属点阵的sers基底及其制备方法和利用该基底进行拉曼检测的方法
CN107091809A (zh) * 2017-06-19 2017-08-25 江苏师范大学 一种银纳米棒阵列表面增强拉曼散射基底的清洗方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104739473A (zh) * 2015-03-12 2015-07-01 东华大学 一种纳米纤维纱线神经导管及其制备方法
CN107290324B (zh) * 2016-04-12 2020-09-08 中国人民解放军军事科学院军事医学研究院 一种联用sers基底检测食品中激素的应用方法
CN107254704B (zh) * 2017-05-10 2018-10-23 昆明理工大学 一种制备镧钙锰氧纳米线阵列的方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103776812A (zh) * 2012-10-17 2014-05-07 胡建明 表面增强拉曼基底的制备方法
CN102910573A (zh) * 2012-10-24 2013-02-06 吉林大学 可揭除保护层的多级金属微纳结构阵列sers活性基底的制备方法
CN103267753A (zh) * 2013-01-15 2013-08-28 江苏大学 一种半导体Fe2O3薄膜型表面拉曼散射基底的制备方法
CN103293142A (zh) * 2013-05-09 2013-09-11 北京大学 一种柔性的表面增强拉曼光谱基底及其制备方法
WO2015009239A1 (en) * 2013-07-17 2015-01-22 Nanyang Technological University Sers-active device and method of manufacturing the device
CN106290296A (zh) * 2016-07-27 2017-01-04 深圳大学 一种基于金属点阵的sers基底及其制备方法和利用该基底进行拉曼检测的方法
CN107091809A (zh) * 2017-06-19 2017-08-25 江苏师范大学 一种银纳米棒阵列表面增强拉曼散射基底的清洗方法

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