CN-122016762-A - Surface-enhanced Raman scattering flexible substrate material and preparation method and application thereof

CN122016762ACN 122016762 ACN122016762 ACN 122016762ACN-122016762-A

Abstract

The invention belongs to the technical field of gas analysis, and relates to a surface-enhanced Raman scattering flexible substrate material, and a preparation method and application thereof. The surface-enhanced Raman scattering flexible substrate material comprises a three-dimensional network structure formed by hydroxypropyl methyl cellulose nanofibers and silver nanoparticles wrapped in the hydroxypropyl methyl cellulose nanofibers, wherein the silver nanoparticles are in a polyhedral structure. The detection limit of thiol compounds in the surface enhanced Raman scattering flexible substrate material can reach 10 ‑19 M level, and trace substances in exhaled air can be detected by the material after the probe is modified on the surface of the silver nano particle. In addition, after the material is stored for 6 months at room temperature, the SERS signal intensity attenuation is less than or equal to 4 percent, and the relative standard deviation of 20 random site detection is only 4.04 percent.

Inventors

XIONG DAI
GAO CHENG
TANG YUN
ZHENG ZEWEI
ZHANG XIAOXIAO
ZHANG KE

Assignees

武汉纺织大学

Dates

Publication Date: 20260512
Application Date: 20260408

Claims (10)

1. A surface-enhanced raman scattering flexible substrate material, comprising: A three-dimensional network structure composed of hydroxypropyl methylcellulose nanofibers; and silver nanoparticles encapsulated within the hydroxypropyl methylcellulose nanofibers; wherein the silver nano particles are in a polyhedral structure.
2. The surface enhanced raman scattering flexible substrate material according to claim 1, wherein: The particle size of the silver nano particles is 100-250 nm, and/or, The mass ratio of the silver nano particles to the hydroxypropyl methylcellulose is (0.10-0.50): 1.
3. The surface-enhanced Raman scattering flexible substrate material according to claim 1, wherein the surface-enhanced Raman scattering flexible substrate material has one or more of the following characteristics: The thickness is 10-100 mu m; The pore size is 1-5 mu m; the porosity is 60% -90%; the specific surface area is 20-100 m 2 /g; the diameter of the hydroxypropyl methyl cellulose nanofiber is 50-500 nm; the roughness Ra value of the surface enhanced Raman scattering flexible substrate material is more than 500nm.
4. The surface-enhanced Raman scattering flexible substrate material according to claim 1, wherein the surface of the silver nanoparticle is further modified with probe molecules, wherein: the probe molecules comprise a first functional group for anchoring to the surface of the silver nanoparticle and a second functional group for capturing the target molecule.
5. The preparation method of the surface-enhanced Raman scattering flexible substrate material is characterized by comprising the following steps of: Dissolving hydroxypropyl methyl cellulose in a water-ethanol mixed solvent, and adding silver nano particles to form a spinning solution; Spinning the spinning solution into a nanofiber membrane through an electrostatic spinning process; and drying the nanofiber membrane to obtain the surface-enhanced Raman scattering flexible substrate material.
6. The method for preparing a surface-enhanced raman scattering flexible substrate material according to claim 5, wherein: the water-ethanol mixed solvent consists of water and ethanol with the volume ratio of (1-3) and/or, The mass ratio of the hydroxypropyl methyl cellulose to the water-ethanol mixed solvent is (1-3) 100, and/or, The mass ratio of the silver nano particles to the hydroxypropyl methylcellulose is (0.10-0.50): 1, and/or, The drying temperature is 50-70 ℃ and the drying time is 2-5 hours.
7. The method of preparing a surface-enhanced Raman scattering flexible substrate according to claim 5, wherein the method further comprises a modification step of probe molecules, the modification step of probe molecules comprising: The method comprises the steps of placing a dried nanofiber membrane into a solution of probe molecules, soaking, and washing to remove probe molecules which are not combined with silver nanoparticles after full reaction, wherein the probe molecules comprise first functional groups for anchoring on the surfaces of the silver nanoparticles and second functional groups for capturing target molecules.
8. A mask comprising the surface-enhanced Raman scattering flexible substrate material according to claim 4.
9. An expired gas detection device, comprising: A mask comprising the surface enhanced raman scattering flexible substrate material of claim 4 for capturing and pre-enriching target molecules in exhaled breath; The Raman spectrum detection device is used for scanning the surface-enhanced Raman scattering flexible substrate material in the mask after use to obtain Raman spectrum signals of target molecules; And the data processing unit is configured to analyze the Raman spectrum signal by adopting a machine learning algorithm, identify characteristic peaks of target molecules and output a detection result.
10. The expired gas detection apparatus of claim 9, wherein the data processing unit comprises: the data preprocessing module is used for carrying out smooth denoising and baseline correction on the Raman spectrum signals; The characteristic extraction module is used for extracting characteristic peak positions and intensity information of target molecules from the corrected spectrum signals; and the intelligent identification module is used for identifying the type and the concentration of the target molecules in the exhaled air based on the characteristic peak information.

Description

Surface-enhanced Raman scattering flexible substrate material and preparation method and application thereof Technical Field The invention belongs to the technical field of Surface Enhanced Raman Scattering (SERS), and relates to a surface enhanced Raman scattering flexible substrate material, a preparation method and application thereof. Background The surface enhanced Raman scattering technology has become a powerful tool for detecting trace chemical biomolecules due to the unique fingerprint identification capability and extremely high sensitivity. In theory, SERS techniques can achieve single molecule level detection. However, in practical solution phase detection applications, particularly in terms of ultrasensitive detection of molecules of critical functional groups such as thiols (-SH), the performance still faces significant bottlenecks. Most SERS substrates at present, even cellulose-based or noble metal-based flexible substrates with better performance, can only reach the level of 10 -12 M to 10 -15 M on the typical detection limit of thiol probe molecules in solution, and are difficult to meet the increasing detection demands of very low concentration markers. The limitation mainly arises from the fact that firstly, silver nano particles (AgNPs) serving as SERS active cores are extremely easy to oxidize, agglomerate or pollute in a high-humidity environment or a complex solution system, so that Local Surface Plasmon Resonance (LSPR) characteristics of the silver nano particles are attenuated, SERS 'hot spots' are insufficient in stability, signals are seriously degraded with time, secondly, the uniformity of signals of a plurality of substrates is poor, the Relative Standard Deviation (RSD) is large, the reliability of quantitative analysis is affected, and furthermore, the traditional high-performance SERS substrates are of rigid structures, so that the application of the traditional high-performance SERS substrates in emerging scenes such as flexible sensing, wearable equipment and the like is limited. The SERS technology is further applied to detection of trace Volatile Organic Compounds (VOCs) in gas phase samples such as exhaled breath of human bodies, and is an important direction for noninvasive diagnosis of diseases, but the SERS technology also introduces more serious challenges, and can be regarded as extension of the solution phase detection bottleneck under more complex scenes. The concentration of target biomarkers in exhaled breath is very low, often in the order of nanomolar to picomolar, and is present in a complex matrix consisting of large amounts of water vapor, carbon dioxide and hundreds of VOCs. This requires not only a higher sensitivity of the substrate, but also an efficient capture and enrichment of the gas molecules. However, conventional SERS strategies optimized for solution detection have very low efficiency of enrichment of gaseous molecules. In addition, direct exposure to warm, humid exhaled air can dramatically accelerate the oxidative deactivation process of silver nanoparticles. Therefore, a SERS substrate with ultrahigh sensitivity, excellent oxidation stability, good signal reproducibility and flexibility is developed to break through the limit of solution phase ultra-trace detection at first, and further lay a foundation for overcoming the difficult problems of high-efficiency and stable detection of gas phase complex samples such as exhaled gas and the like, and has urgent demands and important significance. Disclosure of Invention The invention aims to provide a surface-enhanced Raman scattering flexible substrate material, a preparation method and application thereof, so as to solve the primary problem of insufficient detection sensitivity of a mercaptan compound in a solution by the existing SERS technology and realize high-efficiency and stable detection of trace marker molecules in exhaled gas. According to the invention, the three-dimensional network structure with high specific surface area and rich hydroxyl groups is utilized to increase the specific surface area to actively adsorb and enrich thiol molecules, when the pre-enriched thiol molecules are diffused to the vicinity of AgNPs, the thiol groups of the thiol molecules can form firm Ag-S covalent bonds with the surface of silver, the AgNPs with polyhedral structure provides extremely strong electromagnetic field enhancement, so that the detection limit of the surface enhanced Raman scattering flexible substrate material on thiol compounds such as 4-ATP in solution reaches 10 -19 M level. According to the invention, the probe molecules connected with the silver surface are utilized to adsorb the polar target molecules in the exhaled air, so that the high-efficiency detection of the trace marker molecules in the exhaled air is realized. In addition, the AgNPs are wrapped in the hydroxypropyl methylcellulose (HPMC) nanofiber, so that the AgNPs are protected from being oxidized easily, and the hyd