547 results about "Silver nanoparticle" patented technology

The invention relates to double-layer integrated asymmetric viscous hydrogel as well as a preparation method and application thereof, and belongs to the technical field of hydrogel. The invention relates to a preparation method of double-layer integrated asymmetric viscous hydrogel, which comprises the following steps: adding natural macromolecular polysaccharide and a polymeric monomer into a salt solution, stirring at room temperature, then adding an initiator and a cross-linking agent, stirring and polymerizing to obtain the double-layer integrated asymmetric viscous hydrogel. Through a one-pot method, a salt component is introduced into a hydrogel system, and the hydrogel has a double-layer structure with asymmetric viscosity under the salting-out action; in addition, the hydrogel is doped with a carbon nanotube with the surface modified by polydopamine and silver nanoparticles, so that the mechanical property and the conductivity of the hydrogel are remarkably improved. The preparation method provided by the invention is simple, is suitable for various hydrogel systems, has good universality and is easy to popularize and apply.

The invention discloses a preparation method of an environment-friendly degradable single-sided perspective sticker, and belongs to the technical field of modified nano materials. The method comprises the following steps: (1) preparation of a multi-layer composite structure: mixing polylactic acid and poly (butylene succinate), adding nano-montmorillonite and a surface modifier, and carrying out melt blending to form a first-layer melt; stirring poly (butylene adipate-co-terephthalate) and fluorescent carbon nanodots to form a second layer of melt; the first layer, the pressure-sensitive adhesive layer and the second layer are co-extruded and compounded to form a film blank. And (2) construction of the nano-film: biaxially stretching the film blank, imprinting a micropore array, dipping in the silver nanoparticle suspension, and drying to obtain the nano-film. And (3) coating functionalization treatment: immersing into a fluorine-containing nano coating solution, and curing. And (4) post-treatment: carrying out secondary curing. The obtained single-sided perspective sticker is suitable for the fields of buildings, vehicle privacy films and the like, and solves the problems of serious pollution and slow degradation of a traditional sticker.

A membrane includes a polysulfone-based support, a polydopamine (PDA) layer disposed on a surface of the polysulfone-based support, and a silver / polydopamine (Ag / PDA) composite layer disposed on a surface of the polydopamine layer. The polysulfone-based support has a pore size of up to 600 nanometers (nm). The Ag / PDA composite layer contains core-shell structure particles and spherical particles. The core-shell structure particles have a silver nanoparticle core and a polydopamine shell. The spherical particles are silver-decorated polydopamine particles. The membrane can at least partially separate an Erichrome Black T (EBT) dye from an EBT dye / salt containing mixture by rejecting the EBT dye and allowing the EBT dye / salt containing mixture to pass through the membrane.

The invention provides a method for detecting an external vesicle marker through high-flux nano plasma exciting light immune color development, and belongs to the technical field of human extracellular vesicles. After a serum sample is subjected to centrifugal treatment, the serum sample and a CD81 capture antibody substrate are incubated, and the particle size distribution of the vesicles is monitored in real time; a zwitterionic polymer modified gold nanoparticle LAM detection probe and a polyethylene glycol modified silver nanoparticle LprG detection probe are prepared to be specifically combined with a vesicle surface antigen, a chromogenic enhancement solution is adopted to induce a plasma resonance signal, and full-hole scanning imaging is carried out; and constructing a double-layer game optimization model to cooperatively optimize the detection sensitivity and the signal stability, carrying out weighted summation on normalized signals of the particle size subgroups to obtain comprehensive detection signal intensity, comparing the comprehensive detection signal intensity with a threshold value, and outputting a final judgment result. The technical problem that quantitative accuracy is affected by signal intensity deviation caused by vesicle particle size difference in outer vesicle marker detection is solved.

The invention relates to the technical field of functional coatings of medical instruments, in particular to a temperature-sensitive response type sodium polyacrylate catheter leakage-proof coating, a preparation method and application thereof, and the coating is of a three-layer composite structure. And the bottom bonding layer adopts a polydopamine modified silane coupling agent system, contains silver nanoparticles, has the thickness of 5-15 microns, and ensures strong bonding and antibiosis of the substrate. The middle functional layer is a three-dimensional cross-linking degree gradient interpenetrating network polymer, is composed of a plurality of monomers and nano materials, and is 50-100 [mu] m in thickness, the cross-linking degree of the middle functional layer is gradually increased from inside to outside, gradient transition of mechanical properties is achieved, the outer protective layer is composed of a copolymer, is 3-8 [mu] m in thickness, and provides excellent anti-fouling and biocompatibility. The coating is endowed with strong adhesive force, gradient mechanical property and surface stability, the sodium polyacrylate component absorbs water and expands in urine to form sealing, and the expansion degree of the sodium polyacrylate component is regulated and controlled by the pH value and ionic strength of the urine.

The invention discloses a preparation method of a high-stability manual buffer solution, which comprises the following steps of: introducing two types of slow-release porous particle structures, namely a first type of particles loaded with acidic or alkaline components and a second type of particles loaded with silver nanoparticles, so that continuous slow release and dynamic adjustment of the components in the buffer solution are realized; the pH drift and the aging of a buffer system are effectively delayed; meanwhile, slow release of the silver nanoparticles endows the buffer solution with lasting antibacterial protection, microbial growth is remarkably inhibited, and due to the structural design, the long-term pH stability and storage safety of the buffer solution are remarkably improved, the clarity and physicochemical properties of the buffer solution are guaranteed, and the stability of the buffer solution is improved. The method greatly expands the application range in the fields of high-requirement biological experiments, medical detection, long-term sample storage and the like, the particle addition amount and the component proportion can be flexibly adjusted according to actual requirements, the method adapts to different pH ranges and application scenes, and various experiment requirements of protein purification, long-term sample storage, high-sensitivity analysis and detection are met.

The invention discloses a dressing for promoting pain relief and regeneration of burn wounds and a preparation method of the dressing. The dressing comprises a drug delivery carrier and slow-release multi-effect hydrogel loaded on the drug delivery carrier, the slow-release multi-effect hydrogel is prepared from the following raw materials in parts by weight: 100 parts of water, 7 to 35 parts of multi-effect slow-release microspheres, 3.5 to 10 parts of sodium carboxymethyl cellulose, 2.5 to 8 parts of sodium hyaluronate and 0.5 to 4 parts of glycerol. The dressing provided by the invention has the effects of relieving wound pain, promoting wound regeneration and inhibiting and killing bacteria, the effect of the dressing is long-acting by realizing slow release of various active components (antibacterial carbon dots, silver nanoparticles and bletilla striata polysaccharide), and the dressing has a good application prospect by virtue of matching of the active components and the slow-release effect of the active components. The nursing and treatment effects of burn wounds can be effectively improved, and the application prospect is very good.

The invention belongs to the technical field of gas analysis, and relates to a surface-enhanced Raman scattering flexible substrate material as well as a preparation method and application thereof. The surface-enhanced Raman scattering flexible substrate material comprises a three-dimensional network structure and silver nanoparticles, the three-dimensional network structure is composed of hydroxypropyl methyl cellulose nanofibers, the silver nanoparticles are wrapped in the hydroxypropyl methyl cellulose nanofibers, and the silver nanoparticles are of a polyhedral structure. The surface-enhanced Raman scattering flexible substrate material is used for detecting thiol compounds in a solution, and the detection limit can reach 10 <-19 > M level; after the surface of the silver nanoparticle is modified with the probe, the material can detect trace substances in exhaled air. 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%, and the relative standard deviation detected by 20 random sites is only 4.04%.

The invention discloses an adipose-derived stem cell exosome compound loaded with silver nanoparticles and application of the adipose-derived stem cell exosome compound loaded with the silver nanoparticles, and ADSC-Exos loaded with the silver nanoparticles is developed by integrating AgNPs into an exosome of ADSCs. In vivo, the Exo-AgNPs can accelerate healing of infected wounds by reducing bacterial colonization and promoting collagen deposition, angiogenesis and M2 type macrophage polarization. In vitro, the Exo-AgNPs activates the functions of fibroblasts and vascular endothelial cells, and shows an excellent antibacterial property. In addition, the Exo-AgNPs induces polarization of M2 type macrophages and inhibits secretion of proinflammatory cytokines by activating autophagy. The results show that Exo-AgNPs is expected to become an ideal biological material for treating infected wounds.

This invention discloses a method for preparing ultrafine spherical silver-coated copper powder. A dense film is formed on the surface of copper powder using a specific activator, and this film can quickly form a complex with silver ions in the solution. At the same time, under the action of a specific reducing agent, silver ions are reduced to fine silver nanoparticles and adsorbed on the surface of copper powder. Silver ions in the solution form a dense silver layer on the surface of copper powder through two-dimensional nucleation, resulting in silver-coated copper powder with high density, high conductivity, and high oxidation resistance.

The invention discloses a construction method and application of an SERS (Surface Enhanced Raman Scattering) sensor for detecting Mn < 7 + >. Belongs to the field of detection application, and the construction method of the SERS sensor for detecting Mn < 7 + > comprises the following steps: uniformly mixing an ABTS solution, a to-be-detected solution containing Mn < 7 + > and a silver nanoparticle solution, adding an acid solution to adjust the pH value of a reaction system, and reacting for 1-3 minutes. The SERS sensor for detecting Mn < 7 + > is applied to detection of heavy metal Mn < 7 + >. According to the method disclosed by the invention, by virtue of specific selection of the ABTS on Mn < 7 + > and addition of silver which has extremely high characteristics on SERS detection, convenient and rapid trace detection on Mn < 7 + > is realized. The selective reaction material explored by the invention is used for trace detection of heavy metal Mn < 7 + > by utilizing an SERS technology, and has important significance in application to actual life.

The application discloses a kind of microscale single particle quantitative analysis method and system based on nano-silver signal enhancement, it is related to spectral analysis technical field, the method includes: using laser-induced breakdown spectroscopy system to the carbon black particle target sample is carried out spectral data acquisition, obtains target full spectrum data and is pretreated, and then obtains target spectral data matrix;Variable importance measurement algorithm and continuous projection algorithm are used to the variable in the target spectral data matrix is screened, and target variable is obtained;Target variable is input into carbon black particle metal content prediction model, and the content of metal element in carbon black particle target sample is obtained.The application can quickly and accurately determine the content of metal element in carbon black particle target sample.

The invention discloses a lignin-derived carbon fiber-based sodium metal battery negative electrode material which is prepared by the following steps: performing granulation and melt-blowing on lignin to obtain lignin fibers, performing pre-oxidation and carbonization treatment on the lignin fibers to obtain lignin-derived carbon fibers, soaking the lignin-derived carbon fibers in a silver nitrate saturated solution, taking out the lignin-derived carbon fibers, and drying to obtain the lignin-derived carbon fiber-based sodium metal battery negative electrode material. And carrying out flash burning treatment to obtain the silver nanoparticle / lignin derived carbon fiber composite material. The invention discloses a composite electrode plate for a sodium metal battery, which is prepared by the following steps: grinding a lignin-derived carbon fiber-based sodium metal battery negative electrode material into a short fiber shape, uniformly mixing with polyvinylidene fluoride and N-methyl pyrrolidone to prepare slurry, coating a negative current collector with the slurry, and cutting into pieces to obtain the lignin-derived carbon fiber-based composite electrode plate. The lignin-derived carbon fiber-based sodium metal battery negative electrode material has a three-dimensional interpenetrating network structure, has a high specific surface area, enables an electric field to be uniformly distributed, inhibits dendritic crystal growth, and is suitable for a sodium metal battery system.

This invention discloses a plant-mediated green synthesis method for silver-cerium oxide-attapulgite multifunctional composite nanoenzymes. The method involves mixing cerium nitrate and silver nitrate with an attapulgite suspension, adding honeysuckle extract, adjusting the pH, heating the reaction mixture, centrifuging, washing, drying, and then calcining under a nitrogen atmosphere to obtain the silver-cerium oxide-attapulgite multifunctional composite nanoenzyme. Cerium ions form a complex with the active ingredients in the honeysuckle extract and bind to attapulgite via hydrogen bonds. Calcination yields cerium oxide nanoparticles, while silver ions are reduced by the honeysuckle extract to obtain silver nanoparticles. This invention features a green and environmentally friendly preparation process, simple operation, and easy scale-up. The resulting nanocomposite material exhibits pH-responsive antibacterial and antioxidant multienzyme activity and can be used as an anti-drug-resistant nanomaterial in biomedicine and other fields.

The application discloses a machine learning enhanced silver-based covalent organic framework nanoscale enzyme colorimetric detection method and application thereof, and constructs a covalent organic framework loaded with silver nanoparticles to form a nanoscale enzyme with oxidase-like activity, which is used for rapid visual detection of mercury ions. When mercury ions exist, silver ions in the COF-AgNPs can form silver amalgam with the mercury ions, thereby catalyzing the colorless substrate 3,3',5,5'-tetramethylbenzidine to generate a blue oxidation product oxTMB. The content of mercury can be judged by detecting the absorbance and RGB value changes of the color development reaction. Meanwhile, a machine learning data analysis strategy of a support vector machine model is adopted to perform five-fold stratified cross-validation analysis on the obtained absorbance and RGB values, so that the detection range is expanded and the detection sensitivity is improved.

The invention relates to the field of biological materials and nanotechnology, and discloses a nano lignin-based hydrogel preparation method which comprises the following steps: S1, pretreating more than 15% of lignin-rich cellulose biomass raw materials by using a choline chloride-lactic acid deep eutectic solvent to prepare nano lignin particles; s2, the nano lignin particles are mixed with silver nitrate and sodium hydroxide, and lignin-silver nano particles are synthesized through an oxidation-reduction reaction; s3, adding the lignin-silver nanoparticles into a polyvinyl alcohol solution, and mixing to form a mixture; and S4, carrying out freezing-thawing cycle induced physical crosslinking on the mixture to form the nano composite hydrogel. By forming a compact porous network, the hydrogel not only has good mechanical properties (the tensile strength reaches 0.7-0.9 MPa), but also has good toughness and ductility (1.0-1.3 MJ.m <-3 >) and excellent pressure sensitivity (the pressure sensitivity is 2.5-2.7 kPa <-1 >).

The invention discloses a gel microneedle loaded with silver nanoparticles and a preparation method and application thereof.The extract nano-silver (AB-AgNPs) is prepared through a green synthesis strategy, a drug-loaded microneedle system is constructed based on carboxymethyl chitosan-vanillic aldehyde-polyvinyl alcohol (CMCS-Va-PVA) composite gel, the AB-AgNPs prepared through the technology are uniform in particle size and stable in dispersion, and the drug-loaded microneedle has the advantages that the drug-loaded microneedle is good in drug-loaded performance and good in drug-loaded performance; the crystal has a typical face-centered cubic crystal structure and metal state Ag0 characteristics; the gel microneedle has good mechanical strength and forming effect, the AB-AgNPs and the gel matrix are stably combined through hydrogen bonds, the chemical properties are kept unchanged, and the system has broad-spectrum efficient bacteriostatic activity and biocompatibility; an in-vitro experiment proves that the green synthesized gel microneedle loaded with the silver nanoparticles has a remarkable capability of promoting the healing of L929 cell tissues; a rat wound experiment proves that the gel microneedle can regulate and control an inflammatory factor network and promote cell migration and tissue regeneration, healing of common and infected wounds is remarkably accelerated, and the wound residue ratio in 9 days is as low as 2.7% and 10.9% respectively.

The invention discloses a hydrophobic gas diffusion electrode loaded with silver nanoparticles and application of the hydrophobic gas diffusion electrode in electrocatalytic carbon dioxide reduction, and belongs to the technical field of electrocatalysis. The hydrophobic gas diffusion electrode comprises a gas diffusion layer and a catalyst layer sprayed on the gas diffusion layer; the catalyst layer comprises a silver nanoparticle catalytic material, a first ionomer and a second ionomer; wherein the first ionomer is a fluororesin ionomer, and the second ionomer is a quaternized polysulfone ionomer. A system for preparing CO by reducing CO2 through electro-catalysis is constructed, the system comprises an MEA electrolytic cell, a cathode, an anode and an anion exchange membrane, and the cathode adopts the hydrophobic gas diffusion electrode loaded with the silver nanoparticles. The preparation method is mild in preparation condition and environmentally friendly, the modified hydrophobic gas diffusion electrode has high hydrophobicity, efficient conversion of CO2 can be achieved under the high current density, FECO can reach 96.5% under the high current density, and excellent catalytic performance is shown.

The invention relates to the technical field of hydrogel, in particular to a preparation process of antibacterial hydrophilic hydrogel and application of the antibacterial hydrophilic hydrogel in organoid tissue engineering. The preparation process comprises the following steps: S1, preparing a base material; the base material is prepared from the following raw materials in parts by weight: 300 to 400 parts of deionized water, 60 to 80 parts of acryloyloxyethyl trimethyl ammonium chloride, 40 to 60 parts of polyoxyethylene, 20 to 30 parts of antibacterial agent, 6 to 10 parts of methyl methacrylate and 1 to 3 parts of photoinitiator 1173. According to the preparation method, the contact area between the silver nanoparticles and bacteria is increased, cell membranes are damaged, silver ions are released, chitosan and beta-sodium glycerophosphate form a temperature-sensitive gel precursor after being dissolved, and due to the fact that chitosan carries positive charges, the bacteria can be adsorbed and cell walls can be damaged through the electrostatic interaction; the chitosan and the silver nanoparticles form a slow-release carrier, so that the release time of silver ions is prolonged, and the antibacterial property of the antibacterial hydrophilic hydrogel is further improved.

The invention discloses a preparation method of high-conductivity low-temperature sintered silver paste, which comprises the following steps: sequentially mixing organic silicon resin, a thickening agent, a thixotropic agent, a flatting agent, a defoaming agent and a silane coupling agent with an organic solvent, fully preheating at 50 DEG C, and uniformly stirring; then silver powder is added twice, the micron-sized flake silver powder is added for the first time, the silver nanoparticles are added for the second time, and uniform stirring is performed to obtain premixed slurry; and grinding the premixed paste for multiple times by using a mortar to obtain the finished silver paste. According to the silver paste and the preparation method thereof, the micron-sized flaky silver powder and the silver nanoparticles are mixed to jointly serve as a conductive phase, and the silver nanoparticles with relatively small particle sizes are used for filling pores among the flaky silver powder with relatively large particle sizes, so that a surface film layer of the prepared silver paste is more compact after printing and sintering, and the conductivity is improved. And meanwhile, through the synergistic effect between the flaky silver powder and the silver nanoparticles, the bending resistance of the sintered silver paste is improved.

The invention discloses a machine learning enhanced silver-based covalent organic framework nano-enzyme colorimetric detection method and application thereof, and constructs a nano-enzyme which is formed by loading silver nanoparticles on a covalent organic framework and has oxide-like enzyme activity, and the nano-enzyme is used for rapid visual detection of mercury ions. When mercury ions exist, silver ions in the COF-AgNPs can form silver amalgam with the mercury ions, so that a colorless substrate 3, 3 ', 5, 5'-tetramethyl benzidine is catalyzed to generate a blue oxidation product oxTMB. And the mercury content can be judged by detecting the absorbance and RGB value change of the chromogenic reaction. And meanwhile, a machine learning data analysis strategy of a support vector machine model is adopted to carry out five-fold layered cross validation analysis on the obtained absorbance value and RGB value, so that the detection range is expanded, and the detection sensitivity is improved.

The invention relates to the technical field of immunochromatography analysis, and discloses a signal enhancer of a colloidal gold immunochromatography rapid detection card and a preparation method thereof, the signal enhancer comprises a silver ion solution, a thiourea-ascorbic acid synergistic reducing agent, a pH buffer system and a surfactant stabilizing system, the signal amplification is realized by catalyzing and depositing silver nanoparticles on the surface of colloidal gold, the operation is simple and convenient, one-time addition is realized, and the reaction is completed within 5-10 minutes; the sensitivity is improved by 5-10 times, and the specificity is higher than 98%; the stability is excellent, and the storage time is 12 months at 4 DEG C; various colloidal gold rapid detection cards are universally compatible; compared with the prior art, the colloidal gold immunochromatography rapid detection card has the advantages that the cost is controllable, the single detection is increased by 0.3-0.5 yuan, and the colloidal gold immunochromatography rapid detection card is particularly suitable for ultra-sensitive detection of small molecular substances in the field of food safety, for example, the detection limit of malachite green reaches 0.1 microgram per liter, the detection limit of fipronil reaches 0.5 microgram per liter, and the application range of the colloidal gold immunochromatography rapid detection card is obviously expanded.

The invention belongs to the field of antibiotic analysis and detection, and discloses a quinolone drug SERS (Surface Enhanced Raman Scattering) detection method based on an improved silver nano-substrate and a spectral angle matching model. An improved Lee-Meisel method is adopted to synthesize silver nano sol with precisely controlled particle size, molecular adsorption is realized by utilizing electrostatic interaction of a positively charged quinolone drug and negatively charged silver nano particles, and a high-density Raman enhanced hot spot is formed after an agglomeration agent is added; the SERS spectrum is collected at the excitation wavelength of 785 nm and the integral time of 10 s, qualitative distinguishing of drugs is achieved by combining a spectrum angle matching model, and quantitative detection is achieved by constructing a standard curve through the linear relation between the characteristic peak intensity and the drug concentration logarithm. The detection limit of the four drugs is as low as 1.03-1.16 ppb, the classification accuracy rate reaches 100%, the method is obviously superior to existing similar methods, the detection matrix range is wide, such as animal food and dairy products, and universality and high sensitivity are both considered.

The invention relates to a preparation method of a nano waterproof fabric. According to the method, ellagic acid is introduced in the self-polymerization process of dopamine for in-situ reduction, a polydopamine bonding layer and a silver nanoparticle anchoring layer are synchronously constructed on the surface of nano silicon dioxide, and then perfluorodecyltriethoxysilane is catalyzed by silver nanoparticles for a regioselective click chemical reaction, so that the nano silicon dioxide is obtained. The multifunctional bionic core-shell particles with catalytic activity and super-hydrophobicity are prepared. The particles are compounded with a fluorosilicone copolymer containing dynamic disulfide bonds, a fluorosilicone polymer containing boric acid ester groups and a tannic acid-metal complex to form a double-dynamic cross-linking finishing agent system. After a fabric is subjected to ultraviolet / ozone pretreatment, discontinuous polydopamine nanodot arrays are formed on the surfaces of fibers through short-time dopamine polymerization to serve as catalytic sites, then interface priority crosslinking is triggered by utilizing the sites, and finally, dynamic keys are driven to cooperatively exchange through ultraviolet light fixation and heat treatment, so that the intelligent dynamic waterproof membrane is formed.

The invention provides a preparation method of a hydrophobic silver nanoparticle doped coating, which comprises the following specific steps: preparing silicon shell silver chloride nanoparticles (AgCl (at) SiO2NPs) by taking cetyltrimethylammonium chloride (CTAC), silver nitrate, sodium chloride and tetraethyl orthosilicate (TEOS) as raw materials through a one-pot method, and introducing carbon-carbon double bonds by 3-(methacryloyloxy) propyltrimethoxysilane (MPS) under an acidic condition. In the subsequent distillation-precipitation polymerization process, 4-chloromethyl styrene (VBC) is grafted with chloromethyl, and finally, perfluoropolyether methyl acrylate (PFPEMA) is introduced through atom transfer radical polymerization (ATRP) to form AgCl (at) SiO2-F NPs. Nanoparticles are added into polydimethylsiloxane (PDMS) to be evenly mixed, a silica gel catheter is used for pulling and curing to form the hydrophobic nanoparticle coating SR-F. The hydrophobic nanoparticle coating SR-F is mature in step, firm in film and good in hydrophobicity, and experimental results show that the coating has long-acting antibacterial ability.

The invention relates to a diyne functionalized covalent organic framework material as well as a preparation method and application thereof, and the diyne functionalized covalent organic framework material is synthesized by taking 4, 4 ', 4', 4 ''-(pyrene-1, 3, 6, 8-tetrayl) tetraphenylamine and 5, 5 '-(butyl-1, 3-diyne-1, 4-diyl) diisophthalaldehyde as construction units and adopting a Schiff base reaction. The dialkynyl functionalized covalent organic framework material disclosed by the invention has good chemical stability and can be used as a carrier to controllably grow silver nanoparticles through metal coordination to obtain a composite material, and the composite material shows excellent catalytic activity and cycling stability in a 4-nitrophenol reduction reaction catalyzed by sodium borohydride; therefore, the method has important application potential in the fields of environmental restoration, green chemistry and the like.

The application discloses a preparation method of a VP@UiO-66-NH2 / Ag NPs composite SERS chip and application thereof in A beta protein detection, and is characterized by comprising the following steps: synthesizing a VP-graphite paper base by a chemical vapor transport method on a surface of a graphite paper to obtain a VP-graphite paper base; synthesizing a UiO-66-NH2 layer on the surface of the VP-graphite paper base by a solvothermal method to obtain a VP@UiO-66-NH2 composite base; and finally, placing the composite base in an ion sputtering instrument, uniformly sputtering silver nanoparticles on the surface of the composite base, taking out the composite base, and obtaining the VP@UiO-66-NH2 / Ag NPs composite SERS chip, wherein the VP@UiO-66-NH2 / Ag NPs composite SERS chip has the advantages of high sensitivity, good stability and uniformity, controllable preparation process, low cost, application in Alzheimer's disease biomarker detection, high specificity in identification and quantitative analysis of A beta 40 and A beta 42 proteins, fast response and good stability.

This invention provides a simple synthesis method for Fe-Ag / CMP nanopolymers with catalase-like activity and their application in hydrogen peroxide detection, belonging to the field of bioanalytical technology. The method of this invention includes the following steps: (1) preparing a 4-hydroxyethylpiperazine thiosulfonic acid (HEPES) standard buffer solution; (2) adding cytidine monophosphate (CMP) to the solution obtained in step (1) and stirring until the CMP is fully dissolved. Then, under vigorous stirring, ferric nitrate aqueous solution and silver nitrate aqueous solution are added sequentially, at which point the colorless solution turns pale yellow; (3) transferring the mixed solution obtained in step (2) to a centrifuge tube, centrifuging at 12000 rpm for 8 min to collect the precipitate, washing it three times with distilled water, and finally adding 4 mL of distilled water to obtain a 1 mg / mL Fe-Ag / CMP suspension. This invention utilizes CMP as a biological ligand and Ag... + Fe 3+ Simultaneous coordination, and the reducing amino groups on CMP can directly transfer Ag... + In situ reduction to silver nanoparticles (AgNPs) led to the one-step synthesis of a bimetallic Fe-Ag / CMP nanopolymer with hydrogen peroxide-like nanozyme activity, enabling the detection of hydrogen peroxide.

The invention belongs to the field of nano materials, and particularly relates to an indium selenide nanosheet compound as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: mixing indium selenide nanosheets and silver ions in a second solvent, so that silver nanoparticles grow on the surfaces of the indium selenide nanosheets; the second solvent is a polar solvent, the Hansen solubility parameter delta of the third solvent is greater than or equal to 18MPa < 1 / 2 >, and the mass ratio of the indium selenide nanosheets to the silver ions is (5-50): 1. And growing silver nano-silver particles on the surface of indium selenide by utilizing a spontaneous oxidation-reduction reaction of indium selenide and silver nitrate, so as to prepare the indium selenide nanosheet compound with the surface modified by the silver nano-silver particles. The silver nanoparticles have strong absorption, and the photoelectric response effect of the indium selenide nanosheet is remarkably improved by compounding the silver nanoparticles and the indium selenide nanosheet.

The invention discloses a preparation method of an MF (at) NH2 (at) Ag SERS (Surface Enhanced Raman Scattering) sensor for detecting paraquat and diquat, belongs to the field of nano material synthesis and spectral analysis, and solves the problems that a traditional detection method is complicated in process and cannot detect pesticides and free radicals thereof at the same time, and a traditional SERS substrate is poor in enhancement effect and low in stability. The preparation method comprises the following steps: firstly segmenting melamine foam, cleaning and drying, soaking in hydrochloric acid, soaking in a polyethyleneimine aqueous solution to modify amino, drying, soaking in a silver nitrate solution for ultrasonic treatment, adding a sodium borohydride solution under an ice bath, stirring and reducing, and finally cleaning and drying to obtain the sensor. The sensor takes three-dimensional melamine foam as a support, silver nanoparticles are uniformly loaded on the surface of the three-dimensional melamine foam, paraquat, aquacide and free radicals thereof are enriched through electrostatic interaction based on a localized surface plasma resonance principle, and Raman signal enhancement is realized. The detection limit is 10 <-9 > mol / L, the signal stability and repeatability are excellent, the applicability to actual water sample detection is good, the detection of other pesticides can be expanded, and the method is suitable for on-site rapid trace detection.