阅读说明：本技术 一种特异性检测Ni2+的表面增强拉曼光谱基底及其制备方法和应用 (surface-enhanced Raman spectroscopy substrate for specifically detecting Ni 2+ and preparation method and application thereof ) 是由 张谦 曹雪 张玲 夏立新 孙谦 康博淳 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种特异性检测金属Ni~(2+)的表面增强拉曼光谱基底及其制备方法和应用所述表面增强拉曼光谱基底的制备方法如下：在磁力搅拌下,将NaBH_4加入到的AgNO_3溶液中,得到亮黄色AgNPs溶液,继续搅拌5min后备用,得到AgNPs溶液；将的谷胱甘肽和L-半胱氨酸加入到AgNPs溶液中搅拌,得到目标产物。通过不同浓度的二价镍离子与GSH-Cys-AgNPs中氨基与羧酸基团强力结合,实现纳米基底的不同程度的聚集,通过检测特征峰的拉曼信号来反映Ni~(2+)的浓度。本发明方法具有工艺简单、可操作性强等优点,对制备高性能表面增强拉曼光谱基底具有借鉴意义。(The invention discloses a surface-enhanced Raman spectrum substrate for specifically detecting metal Ni 2+ , a preparation method thereof and a preparation method applying the surface-enhanced Raman spectrum substrate.)

1. The surface-enhanced Raman spectrum substrate for specifically detecting Ni ²⁺ is characterized by being prepared from silver nanoparticles modified by reduced glutathione and L-cysteine.

2. A preparation method of a surface enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ is characterized by comprising the following steps:

1) Adding NaBH ₄ into the AgNO ₃ solution under magnetic stirring at 750r/min to obtain a bright yellow AgNPs solution, and continuously stirring for 5min for later use to obtain the AgNPs solution;

2) Adding the glutathione and the L-cysteine into the AgNPs solution prepared in the step 1) and stirring to obtain a target product.

3. The preparation method of the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ according to claim 2, wherein the reaction is carried out under ice-water bath conditions.

4. The method for preparing the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ according to claim 2, wherein the molar ratio of NaBH ₄ to AgNO ₃ is 1: 0.03-0.06.

5. The method for preparing the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ according to claim 2, wherein the molar ratio of glutathione to L-cysteine to AgNPs is 1: 4-6: 80-90.

6. The method for preparing the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ according to claim 2, wherein the stirring time is 1-3 h.

7. Use of the surface-enhanced raman spectroscopy substrate of claim 1 to specifically detect Ni ²⁺.

8. The use of claim 7, wherein the method comprises adding a solution containing Ni ²⁺ into the surface-enhanced Raman spectroscopy substrate of claim 1, stirring, placing on a silicon wafer, performing Raman spectroscopy, and observing the change of Raman signal peak intensity at 797cm ^-1 and 1639cm ^-1.

9. The use of claim 8, wherein the Ni ²⁺ is quantitatively detected by using the surface enhanced raman spectroscopy substrate, the method comprises adding a solution containing Ni ²⁺ into the surface enhanced raman spectroscopy substrate of claim 1, stirring the solution uniformly, placing the solution on a silicon wafer, performing raman spectroscopy detection, measuring the intensity of raman signal peaks at 797cm ^-1 and 1639cm ^-1, and calculating the ratio of I _797cm ^-1 to I _1639cm ^-1.

10. The use of the reagent kit as claimed in claim 8, wherein the Ni ²⁺⁺ -containing solution is Ni ²⁺ standard solution or Ni ²⁺ -containing sample solution to be tested, and the Ni ²⁺ solution has a concentration of 1X 10 ^-8 mol/L to 1X 10 ^-3 mol/L.

Technical Field

The invention relates to the technical field of surface enhanced Raman spectroscopy, in particular to a Surface Enhanced Raman Spectroscopy (SERS) substrate for specifically identifying Ni ²⁺ and preparation and application thereof.

Background

Surface enhanced raman scattering spectroscopy (SERS) is a surface analysis technique based on detecting molecular vibrations, by analyzing the vibrations of a substance adsorbed in a metal substrate, information such as the structure of the adsorbed substance is obtained, and the type of the substance is determined. The detection molecules are adsorbed on the appropriate metal nanoparticles, and the electromagnetic field effect of the metal nanoparticles is utilized to amplify and analyze vibration information to obtain more accurate spectral signals. The surface enhanced Raman scattering spectrum technology has the characteristic of high sensitivity, so that the technology can detect monomolecular substances and is further applied to detection of various chemical analyses.

^{2+ 2+ 2+}However, the amount of nickel required is very small, and the excessive amount of nickel ions in any organism can cause adverse health effects such as dermatitis, allergy, carcinogenesis and even cell death.

The key point of utilizing the surface enhanced Raman scattering spectroscopy (SERS) specificity to detect metal ions is the preparation of the substrate, and the problem of poor stability of metal nano materials often exists in Raman spectroscopy detection, so the preparation of the surface enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ with high stability and high sensitivity has practical significance.

Disclosure of Invention

The invention aims to realize the selective detection of divalent nickel ions by a surface enhanced Raman scattering spectroscopy technology.

The invention adopts the technical scheme that a surface enhanced Raman spectrum substrate for specifically detecting Ni ²⁺ is a substrate prepared from silver nanoparticles modified by reduced glutathione and L-cysteine.

The preparation method of the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni ²⁺ comprises the following steps:

1) Adding NaBH ₄ into the AgNO ₃ solution under magnetic stirring at 750r/min to obtain a bright yellow AgNPs solution, and continuously stirring for 5min for later use to obtain the AgNPs solution;

2) Adding the glutathione and the L-cysteine into the AgNPs solution prepared in the step 1) and stirring to obtain a target product.

In the preparation method of the surface-enhanced Raman spectroscopy substrate for specifically detecting Ni2+, the reaction is carried out under the ice-water bath condition.

The preparation method of the surface-enhanced Raman spectrum substrate for specifically detecting Ni ²⁺ comprises the following steps of (by mol ratio), NaBH ₄: AgNO ₃ is 1: 0.03-0.06.

the preparation method of the surface-enhanced Raman spectrum substrate for specifically detecting Ni ²⁺ comprises the following steps of mixing glutathione, L-cysteine and AgNPs in a molar ratio of 1: 4-6: 80-90.

according to the preparation method of the surface-enhanced Raman spectrum substrate for specifically detecting Ni ²⁺, the stirring time is 1-3 h.

The application of the surface-enhanced Raman spectroscopy substrate in specific detection of Ni ²⁺ is disclosed.

The application and the method are that the solution containing Ni ²⁺ is added into the surface-enhanced Raman spectrum substrate, the mixture is stirred uniformly and then placed on a silicon wafer for Raman spectrum detection, and the changes of the Raman signal peak intensities at the positions of 797cm ^-1 and 1639cm ^-1 are observed.

The application utilizes the surface-enhanced Raman spectroscopy substrate to quantitatively detect the Ni ²⁺, and the method comprises the following steps of adding a solution containing Ni ²⁺ into the surface-enhanced Raman spectroscopy substrate, uniformly stirring, placing on a silicon wafer, carrying out Raman spectroscopy detection, measuring the Raman signal peak intensities at positions of 797cm ^-1 and 1639cm ^-1, and calculating the ratio of I _797cm ^-1 to I _1639cm ^-1.

in the application, the solution containing Ni ²⁺⁺ is a Ni ²⁺ standard solution or a to-be-detected sample solution containing Ni ²⁺, and the Ni ²⁺ solution has the concentration of 1 multiplied by 10 ^-8 mol/L-1 multiplied by 10 ^-3 mol/L.

The principle of the invention is as follows: the novel surface enhanced Raman substrate material is synthesized by the silver nano particles modified by the reduced glutathione and the L-cysteine, the divalent nickel ions are agglomerated with the modified silver nano substrate material after being identified with the amino groups and the carboxylic acid groups on the surfaces of the modified silver nano particles, the agglomeration degree of the divalent nickel ions and the silver nano particles with different concentrations is different, Raman signals with different intensities are generated for enhancement, and the selective detection of the divalent nickel ions is realized.

The invention has the following beneficial effects

1. According to the invention, due to the recognition and combination of divalent nickel ions with different concentrations and the surface groups of the silver nanoparticles modified by reduced glutathione and L-cysteine, silver nanoparticles with different agglomeration degrees are generated, and further Raman signals with different intensities are generated for enhancement, so that the detection of the substrate Raman signal is realized, and the qualitative or quantitative detection of the divalent nickel ions is further realized.

2. The silver nanoparticle substrate material modified by the synthesized reduced glutathione and L-cysteine has the advantages of good stability and high sensitivity, and solves the problem of poor stability of the metal nano material to a certain extent.

Drawings

FIG. 1 is a dynamic light scattering Diagram (DLS) of GSH-Cys-AgNPs prepared in example 1.

FIG. 2 is a bar graph of dynamic light scattering for example 1 with different concentrations of Ni ²⁺ GSH-Cys-AgNPs added.

FIG. 3a is the Zeta potential diagram of GSH-Cys-AgNPs prepared in example 1.

FIG. 3b is the Zeta potential diagram of GSH-Cys-AgNPs with 7X 10 ^-5 mol/L Ni ²⁺ added in example 1.

FIG. 4a is a graph of the UV-Vis absorption spectra (UV-vis) of GSH-Cys-AgNPs prepared in example 1.

FIG. 4b is a UV-VIS spectrum of GSH-Cys-AgNPs prepared in example 1 with addition of 1.0X 10 ^-8 mol/L to 1.0X 10 ^-3 mol/L Ni ²⁺.

FIG. 5 is an infrared spectrum (FT-IR) of GSH, Cys and GSH-Cys-AgNPs in example 1;

Wherein a is GSH; b is Cys; c is GSH-Cys-AgNPs.

FIG. 6 is an X-ray powder diffraction pattern (XRD) of GSH-Cys-AgNPs prepared in example 1 and GSH-Cys-AgNPs added with 7X 10 ^-5 mol/L Ni ²⁺

Wherein a is GSH-Cys-AgNPs; b is GSH-Cys-AgNPs.

FIG. 7 is a SERS spectrum of GSH, Cys, GSH-Cys-AgNPs (c) and GSH-Cys-AgNPs with 5X 10 ^-5 mol/L Ni ²⁺ added in example 1;

Wherein a is GSH, b is Cys, c is GSH-Cys-AgNPs, d is GSH-Cys-AgNPs with 5X 10 ^-5 mol/L Ni ²⁺.

FIG. 8 is the SERS spectrum of GSH-Cys-AgNPs with addition of Ni ²⁺ of 1.0X 10 ^-8 mol/L to 5X 10 ^-4 mol/L in example 1.

FIG. 9 is a linear fit of I _797cm ^-1/I _1639cm ^-1 in the GSH-Cys-AgNPs SERS spectra of example 1 with 1.0X 10 ^-8 mol/L to 5X 10 ^-4 mol/L Ni ²⁺ added.

FIG. 10 is the SERS spectrum of GSH-Cys-AgNPs with different types of metal ions added in example 2.

FIG. 11 is a histogram of GSH-Cys-AgNPs with different types of metal ions added in example 2.

Detailed Description