35results about How to "Excellent SERS performance" patented technology

The invention relates to the field of MOF-precious metal nanocomposites, and particularly relates to an MOF-precious metal composite SERS substrate and a preparing method thereof. In an alcohol solution, CTAB modified positive-charged precious metal nanoparticles are loaded onto the surface of an MOF material through electrostatic functions to form the MOF-precious metal composite SERS substrate. Compared with in-situ growth methods, the precious metal nanoparticles are loaded onto the surface of the MOF material through electrostatic functions in the method, a high porosity, a high specific surface area and excellent adsorption capability of the MOF material are maintained, morphology, the size and density of the metal nanoparticles on the surface of the MOF can be accurately controlled, and a large amount of Raman active sites are prepared, thus further effectively improving properties of the composite substrate SERS. The MOF-AuNPs composite SERS substrate prepared by the method has double functions including adsorption enrichment and Raman enhancement, does not need surface modification and can achieve direct and highly sensitive detection of molecules such as fluoranthene.

The invention belongs to the field of preparation of nano porous metal materials, and relates to a method for preparing nano porous silver based on an Ag-based amorphous alloy. By the method, the nano porous silver with the aperture of 20-100 nm is finally obtained by preparing a series of Ag-Mg-Ca amorphous alloy thin bands by taking the Ag-based amorphous alloy as a precursor by a solvent quick quenching method and then removing Mg and Ca elements by performing electric chemical alloy component corrosion removal by proper electrolyte. By the method, the structure and the size of the nano porous silver are adjusted and controlled by controlling the amorphous alloy components or electric chemical corrosion temperature; the operation technology is simple; and furthermore, the nano porous silver is extremely high in surface-enhancement raman scattering (SERS) performance and has a wide application prospect in the fields of environment friendliness, catalysis and biological sensors.

The invention discloses an SERS sensor for integrated detection of tumor protein and nucleic acid markers and a preparation method thereof. The SERS sensor comprises a silver nanorod array substrate and an SERS probe, wherein the surface of the silver nanorod array substrate is modified with a tetrahedral DNA structure; the tetrahedral DNA structure is formed by self-assembling six DNA single chains, and three DNA single chains are arranged on three edges of the tetrahedral DNA structure, are respectively connected with three capture chains and are used for respectively and specifically binding nucleic acid and a protein marker. The detection limits of the SERS sensor for detecting nucleic acid and protein respectively reach the Amol/L magnitude and the fg/mL magnitude; the integrated detection of various nucleic acid and protein biomarkers in complex environments such as serum can be realized. The sensor disclosed by the invention is simple to prepare, high in detection sensitivity and good in reliability, can realize high-sensitivity detection of biomarkers with extremely low abundance in the early stage of lung cancer, and has good universality for various tumor biomarkers.

The invention provides a preparation method and application of a molecular imprinted sensor with a silver nanoparticle active substrate, and belongs to the technical field of preparation of functional materials. The preparation method comprises the following steps: step one, preparing Ag nanoparticles with different morphologies; step two, preparing an Ag-MIPs molecular imprinted sensor with thesilver nanoparticle active substrate. According to the preparation method and the application disclosed by the invention, by combining a Raman detection technology with a molecular imprinting technology, a product has sensitive detectability and high selectivity. The invention relates to a novel self-assembly method: the molecular imprinted sensor with the active substrate modified by silver nanoparticles is prepared by using a small amount of acid and a novel method is provided for detecting residual pyrethroid pesticide in river water.

The invention relates to a composite nanomaterial of a core-shell structure, a preparation method thereof and application thereof. The composite nanomaterial has a core-shell structure, and comprises silver nanoparticles serving as inner cores and gold and/or platinum layers serving as outer shells, the surfaces of the silver nanoparticles carry first raman detection molecules, the gold and/or platinum layers wrap the surfaces of the silver nanoparticles, and the outer surfaces, away from the silver nanoparticles, of the gold and/or platinum layers carry second raman detection molecules. The invention further discloses the preparation method and application of the composite nanomaterial. The composite nanomaterial is applied to the diagnosis and treatment process of tumors, and a novel multifunctional molecular probe with low toxicity, high stability, high SERS activity and a photo-thermal treatment effect can be obtained.

The invention discloses an SERS sensor for nucleic acid detection and a preparation and multielement detection method thereof. The sensor is composed of a solid SERS substrate and a nucleic acid probe chain. The nucleic acid probe chain is fixed to the surface of the solid SERS substrate through a gold-sulfur bond, after complementary base pairing with target nucleic acid molecules, sensing detection for nucleic acid is achieved by detecting the SERS signal change of Raman molecules on the probe chain, and exposed loci on the surface of the substrate are sealed through thiol hexyl alcohol. The solid SERS substrate is a silver nanorod array type substrate. The 3' end of the nucleic acid probe chain modifies thiol, the 5' end of the nucleic acid probe chain modifies dye molecules, part of base sequences in the probe chain are complementary to form a hairpin-shaped structure, and part of the base sequences and nucleic acid to be detected can be in complementary pairing. The detection limit of the sensor reaches the fmol level (fM), and joint detection of multiple nucleic acid markers can be achieved. The sensor is easy to prepare, high in detection sensitivity and good in reliability, and has wide application prospects in the fields of early tumor diagnosis and the like.

The invention relates to the field of environment monitoring and discloses a silicon-based SERS chip for quantitatively detecting lead ion concentration in an actual water sample and a preparation method thereof. The chip is composed of: a silicon wafer modified with silver nano particles, gold nano particles, nucleotide sequences represented as the SEQ ID No.1, 2, and 4, and a sequence fragment formed by coupling a sulfydryl group to a 5-terminal and coupling a fluorescent dye to a 3-terminal of a nucleotide sequence SEQ ID No.3. In the invention, the surface enhanced Raman scattering silicon-based chip with assistance of polyadenine is employed for detecting the lead ion, wherein the chip is composed of core (silver) and satellite (gold) nano particles, wherein the DNAzyme covalently connected to the chip can be excited specifically by the lead ions, so that the substrate strand is broken into two free DNA segments. The chip can detect a strong SERS signal, and achieves high sensitivity, specificity, repeatability and recyclability.

The invention relates to SERS-based magnetic test paper for detecting nitrite as well as a preparation method and a use method thereof. The magnetic test paper comprises a super-hydrophobic film, goldnanorods and a magnetic composite, wherein the gold nanorods are erected on the surface of the super-hydrophobic film in bundles after self-assembling; the magnetic composite is entrained among the gold nanorods. The gold nanorods and the magnetic composite are self-assembled on the surface of the super-hydrophobic material to form the magnetic test paper with excellent SERS property. 4-amino thiophenol adsorbed on the surface of the magnetic test paper is coupled with to-be-detected nitrite, and an SERS signal of a coupling product is utilized, so that quantitative and qualitative detectionon the nitrite is conducted indirectly. The magnetic test paper prepared by the method is corrosion-resistant and staining-resistant, has excellent SERS property and magnetism, is convenient to carry,can be rapidly separated out of a complex system under the action of an external magnet, and has wide application prospect in on-site, rapid and high-sensitivity detection on the nitrite in complex samples such as food, environments and biological samples.

The invention relates to the field of preparation of SERS active substrates, and discloses a method for preparing an SERS active substrate based on a grating structure of an optical disc. The SERS active substrate is prepared by performing ink jet printing on the grating structure of the optical disc. The method of the invention has the beneficial effects that ink printing can be accurately carried out in a predefined area of the optical disc through an ink jet printing technology, the consumption of ink can be controlled, the ink waste can be reduced, and the SERS substrate with high repetition rate can also be produced.

The invention discloses a graphene/TiN-Ag composite material. The graphene/TiN-Ag composite material comprises a two-dimensional structure array template which is formed on a silicon wafer and formedby arranging polylactic acid microspheres, a TiN-Ag layer and a graphene layer, wherein the TiN-Ag layer and the graphene layer are alternately deposited on the template. The steps for preparing the graphene/TiN-Ag composite material include that firstly, the polylactic acid microspheres are used for preparing a two-dimensional periodic structure array through a self-assembly technology, and a polylactic acid micro colloidal sphere template is obtained; secondly, TiN layer spin coating and Ag layer magnetron sputtering are conducted; and thirdly, electronic rotation plasma sputtering deposition of the graphene layer is conducted. By means of the graphene/TiN-Ag composite material, due to the compound effect of the graphene layer and the TiN-Ag layer, a substrate can achieve Raman enhancement under various excitation wavelengths, the dependency of the substrate on an excitation light source is overcome to a certain degree, and the Raman analytical application range is enlarged.

The invention discloses a preparation method of a flexible SERS (Surface Enhanced Raman Scattering) substrate, and relates to the technical field of surface enhanced Raman scattering. The preparationmethod comprises steps of (1) primarily oxidizing a carbon cloth; (2) deeply oxidizing the carbon cloth: adding hydrogen peroxide into the reaction system in the step (1) until no bubbles are generated in the reaction system, and cooling to room temperature; and (3) taking out the carbon oxide cloth, cleaning and drying to obtain the flexible SERS substrate. The invention also provides the flexible SERS substrate prepared by the preparation method and application of the flexible SERS substrate in trace detection of organic matters. The preparation method has the beneficial effects that noble metal nanoparticles do not need to be loaded on the carbon cloth, and the commercial carbon cloth is oxidized by adopting a simple oxidation method, so that rich oxygen-containing functional groups aregenerated on the surface of the commercial carbon cloth. By utilizing the charge transfer property between the surface functional group and the organic matter and the foldability of the carbon cloth,the SERS substrate which is flexible and convenient to use is formed.

The invention relates to the technical field of nano photon detection, and discloses a preparation method and application of a ZIF8-derived semiconductor heterojunction-silver SERS substrate, wherein the ZIF8-derived semiconductor heterojunction-silver SERS substrate is of a three-dimensional square nanorod array structure, a TiO2@ZnO heterostructure is used as a substrate, and silver nanoparticles are uniformly attached to the surface of the TiO2@ZnO heterostructure. The preparation method comprises the following steps: growing uniform and ordered three-dimensional TiO2 nanorods in an FTO film material by using a hydrothermal method, then growing ZIF-8 on the surface of TiO2 by using an impregnation method, then calcining to obtain a TiO2@ZnO heterostructure, and finally attaching silver nanoparticles to the surface of the TiO2@ZnO heterostructure by using a silver mirror reaction. The obtained ZIF8 derived semiconductor heterojunction-silver SERS substrate (TiO2@ZnO@Ag) shows good SERS performance in the aspects of sensitivity, stability and uniformity, and the substrate has great application potential in the aspects of qualitative and quantitative analysis of pesticide molecules.

The invention discloses a reusable Raman enhanced substrate as well as a preparation method and application thereof. The method comprises the following steps: preparing ZnO crystal seeds; preparing aZnO array; preparing a ZnO/AuNPs substrate; and preparing the ZnO/Au/Ag152 three-dimensional SERS substrate. The grain size of the Ag152 (SCH2CH2Ph) 60 nanocluster is extremely small, so that hot spots on the original AuNPs film cannot be covered in the deposition process, and the hot spot density on the surface of the AuNPs film can be further increased; and the SERS performance of the original substrate is greatly improved. The substrate has good uniformity and signal reproducibility (RSD being equal to 6.95%), trace detection (5* 10<-12> M) of an analyte can be realized, an enhancement factor can reach 6.48*10 <9>, and recyclable detection can be realized. The method has the advantages of simple preparation process, low cost, high sensitivity, recyclability and the like, and is suitablefor mass production.

The invention provides in-situ loaded porous silver on a copper-based carrier as well as a preparation method and application of the in-situ loaded porous silver. The preparation method of the porous silver loaded on the copper-based carrier in situ comprises the following steps: dissolving silver nitrate and chlorobenzoic acid in water to prepare a mixed solution; and immersing the pretreated copper-based carrier into the mixed solution, reacting, washing and drying to obtain the porous silver loaded on the copper-based carrier in situ. According to the method, the porous silver can be rapidly and efficiently prepared, complex operation steps and reaction equipment are not needed, and large-scale production can be achieved. According to the method, the porous silver can be loaded on the copper-based carriers of different structures in situ, and the loss of the porous silver is reduced; and the porous silver loaded on the copper-based carrier in situ has excellent catalytic performance and SERS (Surface Enhanced Raman Scattering) performance.

The invention relates to an Ag-MOF/AuNRs nano composite material and preparation and application thereof. The nano composite material comprises gold nanorods (AuNRs) serving as a matrix and a metal organic framework (Ag-MOF) self-polymerized on the surfaces of the gold nanorods, and the preparation method specifically comprises the steps of taking and evenly mixing an AuNRs solution and an organic solution containing organic ligands, then adding a silver source solution, carrying out auto-polymerization reaction on the MOF on the surfaces of the AuNRs, and after the reaction is finished, carrying out post-treatment to obtain the Ag-MOF/AuNRs nano composite material. Compared with the prior art, the method has the advantages that the good effect of detecting low-concentration aldehyde substances can be achieved, in addition, the requirement for large-scale rapid analysis in a laboratory can be met, and the aldehyde substances in the environment can be selectively detected.

In the preparation method of AgNR/O-g-C3N4 substrate, O-g-C3N4 modification is carried out on the surface of AgNR to prepare multi-performance nanostructures for sensitive and recyclable SERS analysis. The AgNR/O-g-C3N4 substrate prepared by the preparation method and application thereof in recyclable SERS sensitive detection is disclosed. The method for preparing the AgNR/O-g-C3N4 substrate provided by the invention is simple; in the AgNR/O-g-C3N4 substrate provided by the invention, the O-g-C3N4 on the AgNR/O-g-C3N4 substrate can improve the adsorption capacity of the molecule and improve the SERS performance of the AgNRs and can avoid direct contact between AgNR and the atmosphere which improves the stability of AgNRs; the AgNR/O-g-C3N4 substrate of the invention can produce a significant Raman enhancement effect, and the SERS signal intensity obtained from AgNR/O-g-C3N4 is about three times stronger than unmodified AgNR, and the SERS signal intensity has high reproducibility and stability, has excellent photodegradability, and can perform multiple cycles of detection.