An integrated drilling probe for surface enhanced Raman detection and its application

Abstract

The purpose of the present invention is to provide an integrated drilling probe for surface enhanced Raman detection and its application, which belongs to the field of Raman detection technology. The probe uses an electric drill bit as a substrate, silicon carbide particles are arranged on the surface of the substrate, and gold and silver mixed nanoparticles are arranged on the surface of the silicon carbide particles. Due to the excellent bonding force between the silicon carbide particles, the drill bit and the precious metal nanoparticles, the probe avoids the loss of the metal Raman substrate caused by the drill bit when drilling the sample, so that the probe realizes the integrated function of sampling and Raman detection.

Description

Technical Field

[0001] The invention belongs to the technical field of Raman detection, and in particular relates to an integrated drilling probe for surface enhanced Raman detection and an application thereof. Background Art

[0002] Raman detection is a molecular detection method based on Raman spectroscopy, which has the advantages of high sensitivity and good reliability. However, due to the low intensity of Raman scattering, some means are needed to enhance the Raman signal intensity to increase the applicability of Raman detection. In recent years, studies have found that the electric field around some metal nanoparticles will be greatly enhanced when excited by incident light of a specific wavelength. The Raman spectrum obtained using this principle is called surface-enhanced Raman spectroscopy (SERS). The optical properties of dielectric micro- or nanomaterials are then used to combine the two to obtain a metal-dielectric composite material, and its Raman signal can be further enhanced and stabilized.

[0003] SERS technology can detect extremely low concentrations of test components in various environments. However, the usual detection process requires that after obtaining the test sample, it must be combined with the enhanced Raman substrate by mixing, coating, etc. before testing. The operation is complicated and time-consuming. For example, when sampling and inspecting solid test samples mixed with banned drugs, it is necessary to use an electric drill to take samples, mix the drill cuttings of the test sample with the enhanced Raman substrate, and then conduct testing. However, this method greatly increases the time and cost of the inspection.

[0004] Therefore, how to design a probe for surface enhanced Raman detection so that it can integrate sampling of solid samples and Raman enhanced detection becomes a difficult problem. Summary of the invention

[0005] In view of the problems existing in the background technology, the purpose of the present invention is to provide an integrated drilling probe for surface enhanced Raman detection and its application. The probe uses an electric drill bit as a substrate, silicon carbide particles are arranged on the surface of the substrate, and gold and silver mixed nanoparticles are arranged on the surface of the silicon carbide particles. Due to the excellent bonding force between the silicon carbide particles, the drill bit and the precious metal nanoparticles, the probe avoids the loss of the metal Raman substrate caused by the drill bit when drilling the sample, so that the probe realizes the integrated function of sampling and Raman detection.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] An integrated drilling probe for surface enhanced Raman detection, the probe uses an electric drill needle as a substrate, silicon carbide particles are attached to the surface of the substrate, and noble metal nanoparticles are arranged on the surface of the silicon carbide particles. The noble metal nanoparticles are mixed nanoparticles of nanogold and nanosilver.

[0008] Furthermore, the particle size of the silicon carbide particles is 10 μm-20 μm, and the particle size of the nano-silver and nano-gold particles is 20 nm-30 nm.

[0009] A method for preparing an integrated drilling probe for surface enhanced Raman detection comprises the following steps:

[0010] Step 1: First, a layer of nano-silver particles is prepared on the surface of silicon carbide particles by chemical plating, and then a displacement plating method is used to obtain precious metal mixed nano-gold and nano-silver nano-particles, i.e., metal-dielectric composite particles, on the surface of the silicon carbide particles;

[0011] Step 2: dispersing the metal-dielectric composite particles obtained in step 1 in an acrylic curing agent, and then adding a polymerization initiator to obtain a mixed solution A;

[0012] Step 3: When the mixed liquid A obtained in step 2 has not yet solidified, apply it on the surface of the electric drill needle, and then wait for it to solidify naturally to obtain an integrated detection probe.

[0013] Furthermore, the acrylic curing agent in step 2 is specifically methyl methacrylate, the polymerization initiator is benzoyl peroxide, the volume ratio of the curing agent to the initiator is 1:1, and the amount of metal-dielectric composite particles added is 1-5 mg / mL.

[0014] The present invention also provides an application of the above-mentioned integrated drilling probe in surface enhanced Raman detection, comprising the following steps:

[0015] Step 1. Install the integrated detection probe on the drilling rig, and then drill the sample to be tested;

[0016] Step 2. The Raman spectrometer performs Raman detection on the sample powder to be tested on the surface of the integrated detection probe to obtain the Raman spectrum of the sample to be tested.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] 1. The integrated probe of the present invention arranges dielectric material silicon carbide particles on the surface of the electric drill needle. The material has high hardness, can adhere to the surface of the drill needle, and has good bonding force, so that no deformation and loss occur during the process of drilling the sample to be tested; compared with directly plating gold or silver on the drill needle, the gold and silver nanoparticles chemically plated on the surface of silicon carbide have stronger bonding force, so that the integrated probe can work stably.

[0019] 2. The combination of the enhanced Raman substrate and the drill bit designed in the present invention can perform on-site sampling and sample preparation for solid samples in an integrated manner. The drill bit with drill cuttings attached after drilling can be directly used as a sample for Raman spectroscopy testing without the need for further sample preparation procedures.

[0020] 3. The enhanced Raman substrate of the integrated probe of the present invention adopts metal-dielectric composite particles. The selection of silicon carbide high refractive index dielectric material has ideal optical refraction and focusing effects. While utilizing the plasmon enhancement of precious metal particles, it can further enhance the SERS effect of precious metal nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical picture of the drilling probe with integrated metal-dielectric composite material prepared by the present invention.

[0022] Figure 2 This is a SEM image of silicon carbide coated with gold and silver nanoparticles on the surface of the integrated drilling probe of the present invention.

[0023] Figure 3 This is an EDS image of silicon carbide with gold and silver nanoparticles plated on the surface of the integrated drilling probe of the present invention.

[0024] Figure 4 This is a microscopic photograph of the integrated drilling probe of the present invention after drilling the sample to be tested.

[0025] Figure 5 The Raman test SERS spectra of Example 1, Comparative Example 1 and Comparative Example 2 of the present invention are shown.

[0026] Figure 6 This is a microscopic photograph of the surface of the sample to be tested after the probe of Comparative Example 3 drilled it. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the implementation modes and the accompanying drawings.

[0028] An integrated drilling probe for surface enhanced Raman detection, the probe uses an electric drill needle as a substrate, silicon carbide particles are attached to the surface of the substrate, noble metal nanoparticles are arranged on the surface of the silicon carbide particles, the noble metal nanoparticles are mixed nanoparticles of nanogold and nanosilver; the particle size of the silicon carbide particles is 10μm-20μm, and the particle size of the nanosilver and nanogold particles is 20nm-30nm.

[0029] Example 1

[0030] A method for preparing an integrated drilling probe for surface enhanced Raman detection comprises the following steps:

[0031] Step 1. Prepare noble metal mixed nanoparticles on the surface of silicon carbide by combining chemical plating and displacement plating. The specific process is as follows:

[0032] Step 1.1. Take 0.1 g of silicon carbide particles, disperse them in 1 mL of deionized water, and wash them three times by centrifugation at 3000 rpm with deionized water;

[0033] Step 1.2. At room temperature, take 9 mL of methanol, add 0.2 mL of deionized water, add 75 μL of 72 mmol / L trifluoroacetic acid, and add 0.05 g of solid stannous chloride to obtain a tin sensitized solution;

[0034] Step 1.3. The silicon carbide particles in step 1.1 were mixed with the tin sensitization solution in step 1.2 and rapidly shaken for 30 min, and then centrifuged and washed three times with deionized water at a speed of 3000 rpm;

[0035] Step 1.4. Prepare 9 mL of silver ammonia solution, the ingredients of which are deionized water, silver nitrate, potassium hydroxide, and ammonia water, wherein the concentration of silver nitrate is 25 mmol / L, the concentration of potassium hydroxide is 50 μmol / L, and the amount of ammonia water used is 0.1 mL;

[0036] Step 1.5. Prepare 3 mL of a glucose mixed solution, which consists of sodium citrate, glucose and deionized water, and the concentrations of sodium citrate and glucose are both 50 mmol / L;

[0037] Step 1.6. The washed silicon carbide particles in step 1.3 were mixed with 9 mL of the silver ammonia solution in step 1.4 and stirred in a dark environment for 5 min, and then 3 mL of the glucose mixed solution in step 1.5 was added, and the mixture was stirred in a dark environment for 15 min to prepare silver nanoparticles on the surface of the silicon carbide particles; the particles were then centrifuged and washed 3 times with deionized water at a speed of 3000 rpm, and redispersed into 1 mL of suspension;

[0038] Step 1.7. Soak the silver-plated silicon carbide particles in step 1.6 in a 0.01 mmol / L chloroauric acid aqueous solution for 15 min to prepare gold-silver mixed nanoparticles on the surface of the silicon carbide particles, then centrifuge and wash the particles with ethanol at a speed of 3000 rpm for 3 times, and redisperse them into 1 mL of suspension;

[0039] Step 2. Prepare a solidifying mixed solution, the specific process is: take 1 mL of the solidifying agent, add 10 μL of the composite particle suspension obtained in step 1, then add 1 mL of the initiator, stir evenly, and you can get a mixed solution that naturally solidifies within 20 minutes;

[0040] Step 3. Apply a layer of the solidified mixed liquid obtained in step 2 on the surface of the drill needle, or immerse the drill needle in the mixed liquid and then take it out and let it stand for 20 minutes to solidify, and the required integrated detection probe can be obtained.

[0041] The physical picture of the integrated drilling probe prepared in this embodiment is as follows Figure 1 As shown, the SEM images of the silver and gold particles on the surface of silicon carbide particles are as follows Figure 2 As shown, the EDS surface scanning results of gold and silver elements are as follows Figure 3 As shown. Figure 2 and Figure 3 It can be seen that the surface of the silicon carbide particles has been coated with a layer of gold and silver nano-mixed particles.

[0042] The application of the integrated probe prepared in this embodiment in surface enhanced Raman detection includes the following steps:

[0043] Step 1. Prepare the sample to be tested: Prepare the mixed solution according to the process of step 2 in the preparation method of the integrated detection probe, replace 10 μL of the composite particles with 10 μL of 1 mmol / L methamphetamine ethanol solution, solidify after 20 minutes, and then obtain the sample to be tested;

[0044] Step 2. Install the integrated drilling probe on the drilling rig, and then drill the sample to be tested prepared in step 1;

[0045] Step 6. Perform Raman test on the drill cuttings remaining on the surface of the probe silicon carbide particles: Under a microscopic Raman spectrometer, irradiate the gold-silver coated silicon carbide particles stained with drill cuttings with an excitation light of 785 nm wavelength, perform Raman test, and obtain a Raman spectrum.

[0046] The optical microscope photo of the drill needle after drilling the sample to be tested in this embodiment is as follows Figure 4 As shown, the Raman spectrum is Figure 5 shown.

[0047] Comparative Example 1

[0048] The drill bit with enhanced Raman substrate was prepared according to the steps of Example 1, except that methamphetamine was not added in step 5, and the other steps remained unchanged. The purpose of this comparative example is to detect the SERS spectrum of the curing agent as a control group for detecting toxic materials. The SERS spectrum obtained by this comparative example test is shown in FIG. Figure 5 shown.

[0049] Comparative Example 2

[0050] The metal-dielectric composite material was prepared according to step 1 of Example 1, and directly mixed with 10 μL of 1 mmol / L methamphetamine ethanol solution. After drying, the mixture was subjected to Raman testing according to step 6 of Example 1. The SERS spectrum obtained by this comparative example test is as follows: Figure 5 shown.

[0051] Comparative Example 3

[0052] The steps of Example 1 are followed, except that the silicon carbide dielectric particles are changed to silicon dioxide dielectric particles, or no dielectric particle material is added, and gold and silver particles are directly plated on the surface of the drill bit. Figure 6 shown.

[0053] Figure 4 This is an optical microscope photo of the integrated drilling probe with SERS effect. As can be seen from the figure, the silicon carbide dielectric particles are evenly distributed on the probe surface, and the distribution of gold-silver mixed nanoparticles attached to the surface of each silicon carbide dielectric particle is shown in the figure. Figure 2 As shown, the hybrid nanoparticles are also uniformly distributed on the surface of the SiC dielectric particles.

[0054] Figure 5 The Raman test SERS spectra of Example 1, Comparative Example 1 and Comparative Example 2 are shown in Figure 1. As can be seen from the figure, the signal of the curing agent in Comparative Example 1 and the methamphetamine in Comparative Example 2 both appear in Example 1, indicating that the integrated drilling probe prepared by the present invention can accurately achieve Raman detection.

[0055] Figure 6 The surface micrographs of the probe of comparative example 3 after drilling the sample to be tested are shown in the figure on the left, where the drill bit surface is micrographed after drilling without adding any dielectric particle material and gold and silver particles are directly plated on the drill bit surface, and the right figure is a micrograph of the probe after drilling with silicon dioxide dielectric particles attached to the drill bit probe. It can be seen from the figure that the gold and silver particles on the drill bit surface (left) or the surface of the silicon dioxide microspheres (right) have a large particle loss after the drilling operation, and cannot achieve the binding force of the silicon carbide dielectric particles attached to the probe, and thus cannot realize the application of the probe drilling type.

[0056] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. An integrated drilling probe for surface enhanced Raman detection, It is characterized in that The integrated drilling probe uses an electric drill bit as a substrate, silicon carbide particles are attached to the surface of the substrate, and precious metal nanoparticles are arranged on the surface of the silicon carbide particles. The precious metal nanoparticles are mixed nanoparticles of nanogold and nanosilver. The integrated drilling probe avoids the loss of the metal Raman substrate caused by the drill bit when drilling the sample, so that the probe realizes the integrated function of sampling and Raman detection. The integrated drilling probe is prepared according to the following steps: Step 1: First, a layer of nano-silver particles is prepared on the surface of silicon carbide particles by chemical plating, and then a displacement plating method is used to obtain precious metal mixed nano-gold and nano-silver nano-particles, i.e., metal-dielectric composite particles, on the surface of the silicon carbide particles; Step 2: dispersing the metal-dielectric composite particles obtained in step 1 in an acrylic curing agent, and then adding a polymerization initiator to obtain a mixed solution A; Step 3: When the mixed liquid A obtained in step 2 has not yet solidified, apply it on the surface of the electric drill needle, and then wait for it to solidify naturally to obtain an integrated detection probe.

2. The integrated drilling probe according to claim 1, It is characterized in that The particle size of the silicon carbide particles is 10 μm-20 μm, and the particle size of the nano-silver and nano-gold particles is 20 nm-30 nm.

3. The integrated drilling probe according to claim 1, It is characterized in that The acrylic curing agent in step 2 is specifically methyl methacrylate, the polymerization initiator is benzoyl peroxide, and the volume ratio of the curing agent to the initiator is 1:

1.

4. The integrated drilling probe according to claim 1, It is characterized in that The concentration of the metal-dielectric composite particles in the mixed solution A is 1-5 mg / mL.

5. Application of the integrated drilling probe as claimed in claim 1 in surface enhanced Raman detection, It is characterized in that The following steps are involved: Step 1. Install the integrated detection probe on the drilling rig, and then drill the sample to be tested; Step 2. The Raman spectrometer performs Raman detection on the sample powder to be tested on the surface of the integrated detection probe to obtain the Raman spectrum of the sample to be tested.

Images