59 results about "Functional modification" patented technology

The invention discloses an amyloid-like protein mediated base material surface controllable functional modification method, which comprises the following steps of: dip-coating or spraying an aqueous solution containing protein, a photoinitiator, an anti-fouling monomer and an adhesive monomer on the surface of a base material, and irradiating by ultraviolet rays to form a uniform anti-fouling amyloid protein nano coating on the surface of the base material. Functional monomers and amyloid protein self-assembly are combined, and the effects of adhesion and stubborn stain resistance can be achieved by simultaneously constructing a dual-adhesion unit and a functional anti-fouling unit. The protein nano coating has high optical permeability, on the premise that the original appearance of a base material is not affected, the functions of surface stubborn stain resistance, self-cleaning, stable adhesion and the like are added, stains on the surface of the coating can be washed away through simple water flow washing, and the protein nano coating has wide application prospects in daily life.

The invention provides a preparation method of a substrate of an external vesicle functional marker rapid detection kit, and belongs to the technical field of external vesicle functional marker detection.The preparation method comprises the steps that a high-purity coating working solution is prepared, and precise spraying is achieved through a piezoelectric type ink jet system; substrate functional modification is completed through confining liquid treatment and labeled antibody working solution preparation, a double-layer game model containing detection sensitivity optimization and process stability optimization is established, and an optimal parameter combination is obtained through game iterative calculation by combining the synergistic effect of a quality evaluation function and a stability control function. A characteristic parameter database is established to store historical production data and quality detection results, a multi-parameter joint evaluation method is adopted to calculate a comprehensive score and carry out unified product grading, and a quality control system and a standardized parameter optimization mechanism are driven through full-process data. The technical problem that the quality consistency difference is large in the batch production process is solved.

The application provides a preparation method of a dot array biochip. The application forms a nano-pore dot array on a chip substrate through nano-imprinting, uniformly forms a functional modification layer on the dot array surface through a hydrogel, and then performs etching treatment on the substrate by using a deflected ion beam; an angle between an ion beam incident direction and a surface of a slide stage is θ during etching, so as to perform selective etching on the functional modification layer; through the etching with the angle, the functional modification layer of the bottom and part of the sidewall of the nano-pore can be reserved, and the functional modification layer of other parts is etched clean by the ion beam; the ion source of the IBE is argon, which is stable in chemical property and has no obvious influence on the chemical composition of the material, so that the damage of chemical residues to the performance of the functional material is avoided; the IBE does not produce chemical reaction byproducts, so that the risk of surface residual particles and pollution is reduced; the ion beam energy of the IBE is adjustable, the relatively mild etching avoids damage to the substrate, and the influence on the lattice and surface state of the surface layer material is small.

The invention discloses a method for synthesizing millions of unique DNA tags through primer combination and application of the method, and relates to the field of molecular biology. According to the method, partial complementary pairing characteristics of F, X and Y primers are utilized, and under the synergistic effect of T4 DNA polymerase and ligase, millions of unique DNA tags are generated through one-time reaction through annealing-filling-ligation three-step reaction. The label structure comprises 5'end functional modification sites (such as amino and biotin) and a customizable sequencing joint, and is suitable for high-throughput labeling scenes such as single-cell multiomics, space proteomics and antibody coupling (AOC). Compared with a traditional one-by-one synthesis method, the method has the advantages that the single-tag synthesis cost is reduced by 80% or above, a reaction system is compatible with automatic operation, the tag combination complexity can reach 5.6 * 10 (based on 384 * 384 * 384 primer combination), and an efficient solution is provided for large-scale molecular marking.

The present invention discloses a method for preparing water-soluble quantum dots. The preparation method uses a surfactant solution to coat oil-soluble quantum dots, retaining the fluorescence of the oil-soluble quantum dots, and uses water-soluble polymer ligands (polyvinyl alcohol and polyvinyl pyrrolidone) to complete functional modification, thereby solving the problems of easy quenching of quantum dot fluorescence, inability of nanoparticles to stably agglomerate, and prone to nonspecific adsorption, resulting in low detection sensitivity. When the water-soluble quantum dots prepared by the preparation method of the present invention are used for biomarker detection, they can be directly dissolved in water, and the fluorescent group is stable, can stably agglomerate and specifically adsorb biological targets; therefore, the immunochromatographic test strips prepared using the water-soluble quantum dots can simply and stably adsorb drug antibodies, thereby improving detection sensitivity, with the detection sensitivity for morphine reaching 0.1 ng / mL.

The invention discloses an up-conversion nano-composite with a core-shell structure, a preparation method and application, and belongs to the technical field of biomedical bimodal nano-probes. According to the nanocomposite, up-conversion nanoparticles (UCNPs) serve as a core, metal-organic frameworks (MOFs) serve as a shell layer, horse radish peroxidase (HRP) is loaded on the shell layer, and UCNP (at) MOF / HRP is formed. Subsequent biological functional modification, such as coupling of an antibody, an antigen, nucleic acid and other substances, can be carried by an activating group or a metal coordination bond carried by a shell ligand of the upconversion nanocomposite MOF with the core-shell structure, so that the functions of specific recognition, targeted capture, specific loading and the like are realized.

The invention provides an iron-based nano material, a preparation method and application, the material comprises magnetic iron oxide nano particles and a functional modification layer on the surface, the magnetic iron oxide nano particles are Fe3O4, the particle size is 10-30 nm, and the magnetic iron oxide nano particles have specific oxygen vacancy concentration, 337 nm laser absorptivity and saturation magnetization; the functional modification layer is an amino-containing polymer layer, such as a polydopamine or cysteine-polyethyleneimine copolymer, and can reduce salt ion interference. The material solves the problems of low molecular weight region background interference, non-uniform crystallization, low ionization efficiency, poor salt tolerance and the like during detection of 100-400Da small molecular metabolites in trace samples such as tears and the like by optimizing magnetic responsiveness, photo-thermal conversion capability and salt resistance of an existing matrix; the method realizes high sensitivity and high repeatability (detection), and is suitable for metabonomics analysis of trace biological samples.

The invention discloses a special membrane material for targeted trapping of macrobrachium larvae in water and a preparation method of the special membrane material, and belongs to the field of water environment biological pollution prevention and control. The membrane material is of a multi-layer composite structure and comprises a nanofiber membrane base material layer, an interface adhesion layer and a functional modification layer. The interface adhesion layer is bionic coacervate gel formed by curing hydrophobic polyelectrolyte and phytic acid; the functional modification layer is covalently grafted with a bionic adhesion protein active peptide fragment and a macrobrachium larva chemical pheromone. The material actively attracts larvae to approach through chemical pheromones, high-strength adhesion capture is achieved through bionic peptide fragments rich in aromatic and cationic amino acids, and trapping is integrated. The preparation method comprises the steps of electrostatic spinning of a base material, surface activation, gel coating, functional modification and the like. The material disclosed by the invention has high selectivity and high capture rate on the larvae of the Limnoperna fortunei, is environment-friendly, long-acting and stable, and is suitable for green prevention and treatment of fouling of the larvae of the Limnoperna fortunei in facilities such as water pipelines and pump stations.

The invention discloses a protein-based multifunctional food preservative film as well as a preparation method and application thereof, and belongs to the technical field of functional modification of natural polymer materials. The preparation method of the protein-based multifunctional food preservative film comprises the following steps: firstly, carrying out hydrolysis pretreatment on zein by utilizing the hydrolysis effect of protease, then grafting catechol into a protein structure by utilizing an acyl transfer reaction of TGase, and finally, carrying out functional grafting modification on the zein by utilizing chitosan by utilizing an oxidation reaction of laccase, so as to obtain the protein-based multifunctional food preservative film. The physical and mechanical properties, the stability and the antibacterial activity of the zein film are further improved, and the protein film is endowed with antioxidant activity, so that the protein-based multifunctional food preservative film material suitable for food preservation is prepared. When the protein-based multifunctional food fresh-keeping film is used for fruit fresh-keeping treatment, the shelf life is remarkably prolonged, and the protein-based multifunctional food fresh-keeping film has a good fresh-keeping effect.

The present application belongs to the technical field of extracellular vesicle separation and analysis, and particularly relates to a portable extracellular vesicle separation and analysis system with bubble micro-group self-driven scanning, which comprises a polytetrafluoroethylene micro-flow tube, a dyeing agent, a bubble robot capture carrier with surface antibody functional modification, and a detection module. During operation, the bubble robot is driven by buoyancy to perform reciprocating scanning movement along the axial direction of the tube by tilting the micro-flow tube, so as to actively and efficiently capture target extracellular vesicles in the sample. After capture, the bubble robot is detected by using a fluorescently labeled ssDNA dyeing agent, and the bubble robot transferred to the observation carrier is subjected to fluorescent signal analysis by the detection module. The system integrates new materials and micro-flow control technology, realizes rapid and portable separation and quantitative analysis of extracellular vesicles, solves the problems of existing extracellular vesicle separation technology, such as complicated operation, dependence on large equipment and difficulty in realizing rapid on-site detection, and is particularly suitable for on-site detection of clinical samples.

The present application relates to the technical field of genetic engineering, and particularly provides a Diels-Alder reaction enzyme mutant as well as a preparation method and application thereof. The present application relates to functional modification and strengthening of a Diels-Alder (D-A) reaction enzyme MaDA1 derived from mulberry, so that the enzyme catalyzes intermolecular D-A reaction of a non-natural dienophile containing a ''handle group'' (carboxyl, ester or a precursor thereof) and various dienophiles, so that further modification of the enzymatic D-A product can be realized through decarboxylation functionalization reaction, and diversification and stereoselective synthesis of a cyclohexene skeleton structure are realized.

The application relates to a kind of lipid nanocarriers coupled with GO-203 and loaded with DMAMCL and its preparation method and application, belong to the field of biological medicine and nano-preparation.The lipid nanocarriers include water phase core, lipid bilayer and surface modification layer from inside to outside, wherein water-soluble dimethylamine methyl chloride (DMAMCL) is loaded in the water phase core;The lipid bilayer is wrapped in the water phase core, and coumarin-6 is embedded as fluorescent marker for tracing and detection;Functional modification layer is arranged on the outer surface of the lipid bilayer, including DSPE-PEG2000-COOH and DSPE-PEG2000-GO-203, wherein GO-203 is cell membrane penetrating peptide.The lipid nanocarrier provided by the application can realize the synergistic delivery of GO-203 and DMAMCL, be used for regulating tumor immune microenvironment and be used for the treatment of triple-negative breast cancer.

The present invention discloses an adsorbent for removing excess hepcidin and a preparation method thereof. The adsorbent for removing excess hepcidin is made by using EDTA as a cross-linking agent to form cross-linked chitosan microspheres embedded with zirconium phosphate and / or zirconium oxide, and L-glutathione is bonded to the surface of the cross-linked chitosan microspheres. The adsorbent for removing excess hepcidin of the present invention uses chitosan microspheres as a carrier, and while the microspheres are cross-linked, further bonding ligands are introduced, eliminating the need for additional cross-linking agents and ligands. The reaction conditions are mild, the preparation method is simple, and the cross-linked microspheres have suspended carboxyl groups, which can be further coupled with peptides and amino acids to achieve functional modification. The microspheres can withstand high-temperature steam sterilization and effectively remove excess hepcidin and urea nitrogen from the blood.

The invention belongs to the field of food science and microbial engineering, and particularly relates to fusarium venanii protein, low-lipoprotein food as well as a preparation method and application of the fusarium venanii protein and low-lipoprotein food. The invention provides a fusarium venanii TB01 protein with high emulsibility as well as a preparation method and application of the fusarium venanii TB01 protein. According to the method, fusarium venanii TB01 mycelium is adopted as a raw material, composite enzymolysis and ultrasonic treatment are innovatively and sequentially cooperated, and functional modification of a protein structure is achieved while high-content protein (larger than or equal to 82%) is extracted through efficient wall breaking. Tests show that the two key indexes of emulsifying activity and stability of the obtained protein are obviously superior to those of soybean protein, and the emulsifying stability of the obtained protein is superior to that of commercial whey protein. Therefore, the protein obtained by the invention can be used as a high-performance emulsifying ingredient, is used for replacing or partially replacing whey protein or soybean protein, and is applied to food systems such as beverages, plant yoghurt, sauce and the like.

The invention belongs to the technical field of hot melt adhesive film production, and particularly relates to a hot melt adhesive with a far infrared function and a preparation method thereof, and the preparation method comprises the following steps: S1, synthesizing a photoresponse liquid crystal monomer (Azo-LC); the preparation method comprises the following steps: preparing 4-cyano-4 '-amyl azobenzene through a diazotization reaction, a coupling reaction and post-treatment in sequence, and then introducing a dynamic covalent bond (synthesizing DA-Azo-LC); s2, functional modification of the quantum dots; sequentially carrying out acidification reaction and washing to carry out carboxylation treatment on the GQDs, carrying out CsPbBr3 amino modification through ligand exchange and purification, and hybridizing the carboxylated GQDs and the aminated CsPbBr3; s3, preparing and coating a precursor solution; and S4, carrying out magnetic field-light field synergistic orientation and curing. The azobenzene group is subjected to cis-isomerization under 365nm ultraviolet light and is recovered to trans-isomerization under 450nm blue light, and the arrangement density of liquid crystal molecules can be dynamically adjusted by the conformation change, so that the absorption and emission efficiency of the material to far infrared rays is changed.

The invention belongs to the technical field of DNA coding molecules, and provides a synthesis method of an on-DNA carbonyl compound, which comprises: providing an on-DNA amino compound and an on-DNA hydroxyl compound, the on-DNA amino compound comprising a DNA fragment and an amino group coupled to the DNA fragment, and the on-DNA hydroxyl compound comprising a DNA fragment and a hydroxyl group coupled to the DNA fragment; and reacting the on-DNA amino compound and / or the on-DNA hydroxyl compound with laccase and an auxiliary catalyst to obtain the on-DNA carbonyl compound, namely the on-DNA carbonyl compound containing a DNA fragment and carbonyl coupled with the DNA fragment. The synthesis method has the advantages of mild conditions, environmental friendliness and small damage to DNA, and is suitable for construction of a DNA coding molecular library, fluorescence labeled molecule coupling performed by using an on-DNA carbonyl reaction handle, DNA modification coupling and functional modification in targeted drug delivery.

The invention discloses a selenol-alkynyl click (SYC) chemically mediated cell surface rapid functional modification method, which mainly comprises the following steps: firstly, introducing selenol functional molecules into the surface of a living cell, so that the surface of the living cell is modified with an active selenol group to form a selenolated cell surface, and then carrying out surface modification on the selenolated cell surface to obtain a selenol-alkynyl click (SYC) chemically mediated cell surface; then, a biocompatible material carrying an alkynyl functional group is in contact with the surface of the selenolated cell, and covalent coupling of the biocompatible material and the surface of the selenolated cell is realized through a selenol-alkynyl click reaction under a physiological compatible condition, so that the cell is endowed with new properties or functions; and a novel method is provided for research on cell surface functionalization and regulation of specific interaction between cells. The application range of selenol-alkynyl click chemistry in the field of biomedicine is expanded, an existing cell surface chemical modification tool box is further enriched, and a new tool is provided for the fields of clinical diagnosis, tumor immunotherapy, basic cell biology research and the like.

The present invention discloses a high-biobased content mildew-proof, antibacterial and water-resistant soy protein adhesive and its application. The preparation method is as follows: first, polyphenol and soluble metal salt are dissolved in water, and a chelation reaction is performed to obtain a functional modification reagent containing polyphenol chelated metal nanoparticles. Then, a soy protein aqueous solution is prepared, the pH is adjusted, and heated and stirred. Finally, a functional modification reagent containing polyphenol chelated metal nanoparticles is added, the pH is adjusted with acid, and a bio-based cross-linking agent is added. The cross-linking reaction is stirred and mixed, and the material is uniformly discharged to obtain a high-biobased content soy protein adhesive. Different from most existing studies that use a large amount of petrochemical-based modification additives, the present invention has a higher biomass content. The dry and wet strengths of plywood made from the high-biobased content adhesive can reach up to 2.83MPa and 1.78MPa, respectively, and it has high water resistance, heat resistance, flame retardancy, mildew resistance, and antibacterial capabilities.

The invention provides a bacterial outer membrane vesicle capable of efficiently targeting tumors and a preparation method of the bacterial outer membrane vesicle, and relates to the technical field of biological medicines. The target protein PDL1 binding peptide is successfully modified on the surface of the bacterial outer membrane vesicles to prepare the bacterial outer membrane vesicles PDL1-OMVs, the particle size range of the bacterial outer membrane vesicles PDL1-OMVs is 20-250 nm, and the bacterial outer membrane vesicles PDL1-OMVs have an obvious saucer-like double-layer membrane structure and accord with the structural characteristics of the bacterial outer membrane vesicles. According to the PDL1-OMVs provided by the invention, on one hand, the defect that the PD-L1 binding peptide is weak in targeting efficacy is improved, the targeting capability of the PD-L1 binding peptide is remarkably improved, on the other hand, targeting function transformation is realized on the bacterial outer membrane vesicles, and the PDL1-OMVs can realize a specific targeting effect on tumor cells, so that conditions are provided for the PDL1-OMVs serving as a carrier for targeted delivery of tumor drugs.

The application provides an electroluminescence-enhanced biosensor and a preparation method thereof. The electroluminescence-enhanced biosensor comprises, from bottom to top, a flexible substrate, a coplanar electrode layer, a mixed luminescence layer, a functional modification layer and a biological recognition layer which are sequentially stacked; the coplanar electrode layer is formed by forming a pair of parallel electrodes on the flexible substrate with a conductive material; the mixed luminescence layer is formed by uniformly coating an alternating current electroluminescence material on the coplanar electrode layer; the functional modification layer comprises an adhesion layer arranged on the mixed luminescence layer and a material layer arranged on the adhesion layer; the adhesion layer is made of a positively charged biocompatible polymer, and the material layer is made of a two-dimensional material containing a phosphate group; the biological recognition layer is formed by fixing specific antibodies on the material layer and then sealing unreacted sites with a sealing material; after a sample to be measured is added to the biological recognition layer, an alternating current voltage is applied, and a detection signal is read.

The present application belongs to the field of food science and microbial engineering, and specifically relates to a fusarium venenatum protein, a low-fat protein food and a preparation method and use thereof. The present application provides a high-emulsifying fusarium venenatum TB01 protein, a preparation method and application thereof. The present application uses fusarium venenatum TB01 mycelium as raw material, and innovatively realizes the functional modification of protein structure by sequentially cooperating complex enzymolysis and ultrasonic treatment, thereby efficiently breaking the cell wall to extract high-content protein (≥82%) and realizing the functional modification of protein structure. Tests show that the emulsification activity and stability of the obtained protein are significantly better than those of soybean protein, and the emulsification stability is better than that of commercial whey protein. Therefore, the protein obtained by the present application can be used as a high-performance emulsifying ingredient to replace or partially replace whey protein or soybean protein, and is applied to beverage, plant yogurt, sauce and other food systems.

The invention discloses a fertilizer synergist based on marine biogen functional group modification and a preparation method and application thereof, and relates to the technical field of agricultural biotechnology and novel fertilizer additives, and the preparation method comprises the following steps: raw material pretreatment: taking marine algae, shellfish or marine fish processing leftovers as raw materials, cleaning, crushing to 60-100 meshes, and drying to obtain the fertilizer synergist; according to the method, marine biogen is taken as a raw material to obtain marine biogen coarse powder, active functional groups such as sulfonic groups and carboxyl groups are successfully introduced to a molecular skeleton of the marine biogen through alkaline hydrolysis and a specific functional group directional modification process, and a final product has high cation exchange capacity and pH buffer characteristics based on Hexchange and neutralization reaction through ion exchange treatment; the synergist can adsorb and preserve nutrient ions, and after the synergist is applied to soil, through interaction of functional groups of the synergist and ions of a rhizosphere environment, the pH of a micro-domain can be easily adjusted to be neutral, so that favorable conditions are created for effective utilization of nutrients, and meanwhile resource utilization of marine processing leftovers is achieved.

The invention discloses a fluorescence analysis and detection method and system based on quantum dots, and belongs to the technical field of analysis and detection. According to the method, functional modified quantum dots are used as fluorescent probes, a fluorescence detection system is constructed through specific recognition reaction, and high-sensitivity and high-specificity detection of a target detection object is realized by combining collection and quantitative analysis of fluorescence signals. The corresponding system comprises an excitation light source module, a sample reaction module, a fluorescence detection module, a data processing module and a control module, all the modules work cooperatively, key parameters in the detection process can be precisely regulated and controlled, and the detection precision and stability are improved. The method solves the problems of poor probe stability, low quantum yield and high detection limit in a traditional fluorescence detection method, has the advantages of high detection speed, high specificity and wide application range, and can be widely applied to the fields of food safety detection, environmental pollutant monitoring, biomedical diagnosis and the like.

The invention discloses magnetic biochar as well as a preparation method and application thereof. The preparation method comprises the following steps: calcining agricultural wastes containing organic matters to obtain a biochar initial material; soaking the biochar initial material in a mixed solution containing an iron source, a reducing agent and an alkalinity regulator; and then carrying out hydrothermal reaction. The biochar precursor is prepared from agricultural wastes containing organic matters, such as comprehensive solid particles in aquaculture tail water, and complex components and original characteristics of the biochar precursor are reserved to the greatest extent. Meanwhile, the biochar is subjected to magnetic functional modification, the dual advantages of rapid adsorption and convenient recovery are achieved, and the problem that conventional biochar is difficult to separate, recover and reuse from the water body is solved. According to the method, resource utilization of solid particles in the breeding tail water can be achieved, meanwhile, antibiotic pollutants can be effectively removed, and the spreading risk of drug-resistant bacteria is reduced.

The invention discloses a targeted nano-vesicle for stage-specific tissue repair as well as a preparation method and an application method of the targeted nano-vesicle. The nano vesicles are formed by fusing cell membranes of dominant cells at different stages in the tissue repair process in an equal mass manner. And the system can be used for accurately delivering and regulating key cells in different tissue repair stages, so that the synergistic promotion of dynamic remodeling of a regeneration environment and tissue regeneration is promoted. The cell membrane is extracted by adopting a low-temperature buffer solution system, the fused cell membrane is formed after mixed incubation, and then the nano-vesicles are prepared by adopting a mechanical membrane extrusion method, so that the membrane protein function and structural characteristics of the source cell membrane are reserved, the stability in a physiological environment is good, the biological safety is good, and obvious immunoreaction or toxicity cannot be caused. And the method has the advantages of low cost, mild process and easiness in large-scale popularization. Through glucose functional modification, the active recognition and targeting capabilities are further enhanced, the limitation of a traditional static targeting or sequential release system is broken through, and the system has a wide application prospect.

The invention discloses a method for treating livestock and poultry wastes by using hermetia illucens, and belongs to the technical field of waste utilization. The method comprises the following steps: mixing and fermenting livestock and poultry manure, straw and wheat bran, adding a modifying functional agent to prepare a feed, putting hermetia illucens eggs, controlling proper environmental conditions to promote growth of larvae, separating larvae from fecula after the larvae are mature, collecting the larvae, and composting the fecula to prepare the organic fertilizer. Compared with the prior art, by optimizing the treatment process and adding the specific modifying functional agent, the treatment efficiency and the resource utilization degree of the hermetia illucens on the livestock and poultry waste are remarkably improved, meanwhile, the environmental pollution risk in the treatment process is reduced, and the growth performance and the survival rate of the hermetia illucens larvae are improved.

The invention discloses a nano-microsphere time-resolved fluorescent probe as well as a preparation method and application thereof. The preparation method comprises the following three steps: preparation of core-layer nano microspheres, shell-layer functional modification and fluorescence enhancement and stabilization treatment. A polylactic acid-glycolic acid copolymer (PLGA) is used as a core-layer carrier to load a rare earth ion complex, and a SiO2 coating layer and a targeting ligand are combined for modification, so that the nano-microsphere fluorescent probe with a core-shell structure is prepared. The probe has the characteristics of long fluorescence lifetime (5-8ms), high quantum yield (greater than or equal to 35%), strong stability, excellent targeting property and the like, and can be widely applied to food safety detection (such as quinolone antibiotics and microcystin MC-LR) and environmental pollution detection (such as heavy metal ions such as Hg < 2 + > and Pb < 2 + >), and the detection limit is as low as 0.05 ng / mL or 0.1 nmol / L. The problems that a traditional fluorescent probe is low in loading capacity, poor in stability and insufficient in targeting property are solved, and the method has remarkable industrial application value.

The application provides a kind of extracellular vesicle quantitative detection method based on self-interference spectrum reconstruction, it is related to the intersection field of biomedical detection and optical engineering.The method comprises: adding clinical sample into digital microfluidic chip, and separating sample droplet from droplet with functional modification magnetic bead by electrode;After mixing two droplets, add vesicle binding solution and mix, then incubate;Through magnetic control fixed magnetic bead, remove solution, then add deionized water to clean magnetic bead;After removing magnetic bead cleaning solution, add vesicle eluent and incubate with magnetic bead;Separate out the droplet containing extracellular vesicle;Transfer the droplet containing extracellular vesicle to the upper of gold-coated glass, remove droplet after incubation;Use deionized water to clean hybridized gold-coated glass;Use self-interference spectrum imaging system to detect vesicle quantity and its particle size distribution.The application can realize extracellular vesicle quantitative counting, particle size measurement and surface protein marker detection simultaneously, and improve single vesicle quantitative imaging precision and detection efficiency.

The invention discloses a bio-based antibacterial agent based on yeast fermentation and a preparation method of the bio-based antibacterial agent in the field of antibacterial agents. The bio-based antibacterial agent comprises the following components in parts by weight: 2-4 parts of modified chitosan, 1 part of modified polyethylene glycol, 0.2-0.3 part of pig gastric mucoprotein and 0.6-0.8 part of sodium alginate. According to the invention, a gene corresponding to an amino acid sequence of tachyplesin is optimized; according to the invention, a pYES2 / CT vector is used as a target gene, an EcoR I / Xho I restriction enzyme cutting site is introduced to a 5 ' / 3' end, it is ensured that the target gene can be accurately inserted into the pYES2 / CT vector, Tachyplesin-1 is a natural antibacterial peptide, a killing effect can be realized by destroying cell membranes of harmful bacteria and interfering metabolism of the harmful bacteria, and Tachyplesin breaks through intestinal environment limitation and accurately acts on the harmful bacteria through coating and functional modification of a modified vector.

The application provides a kind of high-efficiency tumor-targeting bacterial outer membrane vesicle and its preparation method, it is related to biological medicine technical field.The target protein PDL1 binding peptide is successfully modified on the surface of bacterial outer membrane vesicle to prepare bacterial outer membrane vesicle PDL1-OMVs, its particle size range is between 20-250nm, with obvious tea tray like double membrane structure, meet the structural characteristics of bacterial outer membrane vesicle.The PDL1-OMVs provided by the application improves the weak targeting efficiency of PD-L1 binding peptide on the one hand, significantly improves the targeting ability of PD-L1 binding peptide, on the other hand, realizes the targeted functional modification of bacterial outer membrane vesicle, and PDL1-OMVs can realize specific targeting effect on tumor cells, which provides conditions for it as a targeted delivery tumor drug carrier.