CN-122011273-A - Preparation method of nano gold polymer composite material and SERS application thereof

Abstract

The invention discloses a nano gold polymer composite material for Surface Enhanced Raman Scattering (SERS) and a preparation method thereof. The material is prepared from monomers, a cross-linking agent, a photoinitiator, tetrachloroauric acid and water. The preparation method comprises the steps of preparing a gold source precursor solution, preparing a photo-curing premix, mixing to form liquid photosensitive resin, forming a composite film through ultraviolet light curing, and performing heat treatment to obtain a final product. The method does not need to add reducing agent and subsequent purification, realizes polymer generation and nano-gold reduction synchronously through one-step photopolymerization, and has simple process, mild condition and environmental protection. The obtained nano gold is mainly triangular, polygonal and polyhedral, has rich tip and edge structures, is uniformly dispersed in a polymer, has no aggregation, can effectively form SERS hot spots, and is suitable for SERS substrates.

Inventors

• WANG HUI
• XU CHANG
• ZHANG YI
• ZHU ZHAOWEN
• YIN YUTING
• WU YOU
• HUANG BEIQING

Assignees

• 北京印刷学院

Dates

Publication Date

20260512

Application Date

20251226

Claims (9)

1. 1. The nano gold polymer composite material is characterized by being prepared from a monomer, a cross-linking agent, a photoinitiator, tetrachloroauric acid and water, and the preparation method comprises the following steps: Mixing aqueous solution containing tetrachloro-gold acid with photo-curing premix containing monomer, cross-linking agent and photoinitiator, performing ultrasonic dispersion, performing ultraviolet curing cross-linking to form a film, and performing heat treatment to form the nano-gold polymer composite material.
2. 2. The nanogold polymer composite material according to claim 1, wherein the monomer is DMAAM, HEMA or a combination thereof.
3. 3. The nanogold polymer composite according to claim 1 wherein the crosslinking agent is PEGDA with a molecular weight of 200 to 1000.
4. 4. The nanogold polymer composite according to claim 1, wherein the monomer is PEGDA with a molecular weight of 200.
5. 5. The nanogold polymer composite according to claim 1, wherein the part ratio of the monomer to the crosslinking agent is 1:3 to 3:1.
6. 6. The nanogold polymer composite according to claim 1 wherein the photoinitiator is 819DW or 2959.
7. 7. A nano-gold polymer composite material according to claim 1, wherein the ultraviolet light irradiation time is 2 to 12 minutes.
8. 8. A nano gold polymer composite material according to claim 1, wherein the mass ratio of the tetrachloroauric acid to the water is 1:28-9:20.
9. 9. The method of claim 1, wherein the nano-gold polymer composite is used for patterning in a two-dimensional plane or a three-dimensional space in combination with mask exposure, printing, coating, or stereolithography.

Description

Preparation method of nano gold polymer composite material and SERS application thereof Technical Field The application relates to the technical field of Surface Enhanced Raman Scattering (SERS) substrate materials, in particular to a nano gold-polymer composite film prepared based on in-situ photopolymerization and thermal reduction and application thereof in SERS detection. Background Surface Enhanced Raman Scattering (SERS) is a spectrum analysis method with high sensitivity, high detection speed and good accuracy, amplifies Raman scattering signals of target molecules through nano particles or nano structures on the surface of a substrate, can realize nondestructive detection, and has important application value in the fields of environmental analysis, biological medicine, food safety and the like. At present, the academic world generally considers that SERS has two mechanisms of electromagnetic enhancement and chemical enhancement, wherein the electromagnetic enhancement mechanism mainly comes from local surface plasmon resonance generated by a noble metal nano structure or a rough surface, so that noble metal nano materials such as gold, silver and the like are widely applied to SERS substrate preparation. Under the nanoscale, the tips and edges of the noble metal nano structures can generate local strong electric fields and tip effects to form a larger electric field intensity area, namely a hot spot required by SERS, so that the purpose of enhancing the SERS effect can be achieved by regulating the appearance of noble metal particles and increasing the number of protrusions and tips. Common preparation methods of noble metal SERS substrates can be divided into two main types of 'top down' and 'bottom up'. The top-down method mainly refers to direct processing by photoetching and etching technology or combination with a template method, such as Klarite SERS chips developed by Renisshaw corporation, and the method can accurately prepare highly ordered nano structures, but often requires special experimental equipment, has higher process complexity and cost, has limited adjustability and can not synthesize anisotropic nano particles. The bottom-up method is to prepare metal nanoparticle sol by chemical synthesis means, and then self-assemble or continue in-situ growth on a substrate to obtain the nanostructure. The method has lower accuracy and stability for nano structure regulation than the 'top down' method, but does not need expensive special equipment, and has wider research. The composite material of the nano gold and the polymer has the advantages of physical and chemical properties of noble metal and easiness in processing and forming of the polymer, and is widely applied to SERS substrates. The preparation method of the nano gold polymer composite material can be divided into two main types, namely, 1, a physical blending method, namely, pre-synthesizing nano gold, blending the nano gold with a polymer, wherein the method has the problems of agglomeration, uneven dispersion and the like of nano Jin Yi, and the preparation steps are complicated, namely, the chemical synthesis of the nano gold generally comprises the steps of seed crystal preparation, chemical reduction, seed growth, surface modification, protection, separation, purification and the like, and then the nano gold is mixed with a polymer system, dispersed, dried and the like. 2. In-situ synthesis methods, such as reduction of gold precursors (e.g., HAuCl 4) in polymers, direct in-situ nucleation, growth and uniform dispersion of the gold nanoparticles in the polymer network, avoid the problem of nanoparticle agglomeration in the physical mixing method, and improve the uniformity and stability of the composite material. The prior art discloses some related art, such as: "Polymer nanocomposites for plasmonics: In situ synthesis of gold nanoparticles after additive manufacturing"Polymer Testing, 2023, 117: 107869. A polymer composite material is prepared by doping a gold precursor KAuCl 4 into photoresist, carrying out photo-curing three-dimensional printing and forming, and then carrying out heat treatment in-situ reduction to generate gold nanoparticles, wherein the method still has the following technical problems that firstly, KAuCl 4 is adopted as a gold source, potassium ion impurities are introduced, background signal interference or nonspecific interaction with molecules to be detected easily occurs in a Surface Enhanced Raman Scattering (SERS) detection process, the detection sensitivity and reproducibility are seriously affected, secondly, due to extremely low solubility of KAuCl 4 in an organic photoresist system, only 0.1-1wt% of doping amount can be realized in the literature, the gold nanoparticles in the final composite material are insufficient, high-density plasma 'hot spots' are difficult to form, SERS enhancement factors are obviously weakened, and further, the post-treatment is carried out at a high temperature of