78 results about "Non specific adsorption" patented technology

The invention provides a nylon 6 nanofiber virus-removing filtering membrane and a preparation method and application thereof.The nylon 6 nanofiber virus-removing filtering membrane comprises a base material and a nylon 6 nanofiber membrane compounded to the surface of the base material, the average pore size of the virus-removing filtering membrane is 20 nm, the virus-removing filtering membrane plays a role in blocking parvoviruses, the surface of the virus-removing filtering membrane is charged, and the surface of the virus-removing filtering membrane is not prone to being damaged. Proteins with the same charges on the surface can be prevented from adhering to the surface of the fiber. In the preparation process of the virus-removing filtering membrane, the nylon 6 nanofibers with a certain diameter range are selected and compounded on the surface of the base material in a stable dispersion state, the uniform microporous virus-removing filtering membrane is prepared, the effect that parvoviruses are blocked and protein molecules are not easily intercepted is achieved, the hydrophilicity of the nylon 6 nanofibers is relatively good, and the virus-removing filtering membrane has a good application prospect. The non-specific adsorption of the filtering membrane on the protein is reduced; the nylon 6 nanofiber virus-removing filtering membrane can be applied to the field of biological medicine products, and has important significance on separation and purification of biological preparations.

The invention provides an electrochemical biosensor based on ultrasonic bidirectional driving and a detection method, and belongs to the technical field of biosensing. The sensor comprises a porous membrane and an ultrasonic bidirectional driving unit, and a probe capable of specifically capturing a target object is fixed in a pore channel of the porous membrane; the ultrasonic bidirectional driving unit is composed of a first ultrasonic transducer and a second ultrasonic transducer which are symmetrically arranged on the two sides of the porous membrane, and can synchronously execute reverse power gradient change to form alternately changing pressure difference on the two sides of the membrane so as to drive liquid to repeatedly penetrate through the porous membrane. The detection method comprises the steps of to-be-detected liquid injection and ultrasonic bidirectional driving, ultrasonic auxiliary cleaning and electrochemical detection. The problems of insufficient probe utilization rate, low mass transfer efficiency and non-specific adsorption of a traditional passive diffusion mechanism are solved by utilizing bidirectional ultrasonic active driving force, the detection sensitivity, speed and signal-to-noise ratio are remarkably improved, and the method is suitable for rapid and high-sensitivity quantitative analysis of various analytes.

This invention discloses a method and sensor for adiponectin detection using a polyaniline and polyacrylic acid-modified wire mesh carbon electrode, relating to the field of adiponectin detection technology. The method involves electrochemically activating the wire mesh carbon electrode, electropolymerizing it to form a polyaniline-polyacrylic acid composite modification layer, immobilizing adiponectin monoclonal antibody after activation with N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, blocking the antibody with bovine serum albumin, and reacting it with a serum sample. The adiponectin concentration is determined based on the peak potential shift and peak current change. This invention simultaneously achieves both conductive transport and antibody immobilization, reduces non-specific adsorption and serum interference, and improves detection sensitivity, repeatability, and quantitative accuracy.

This invention belongs to the field of biosensing and detection technology, specifically disclosing a Tau protein electrochemiluminescent aptamer sensor, its preparation method, and its application. The sensor uses a CsPbBr₃@PVP / Au composite material as the electrochemiluminescent substrate. A Tau protein-specific aptamer is immobilized on the substrate surface via Au-S bonds, and non-specific adsorption sites are blocked with 6-mercapto-1-hexanol. The CsPbBr₃@PVP / Au composite material is prepared by encapsulating CsPbBr₃ with PVP and then combining it with Au NPs. This invention utilizes the coordination passivation effect of PVP and CsPbBr₃ to significantly improve the aqueous stability and electrochemiluminescence efficiency of perovskite nanocrystals. Combined with the anchoring effect of AuNPs and the specific recognition effect of aptamers, it achieves ultrasensitive detection of Tau protein with a detection limit as low as 0.80 fg / mL. Furthermore, it exhibits excellent selectivity, stability, and detection accuracy in complex biological samples such as cerebrospinal fluid, providing a novel and efficient detection platform for the early diagnosis of Alzheimer's disease and showing promising clinical application prospects.

The invention relates to the technical field of traditional Chinese medicinal material detection, and particularly discloses an alpha-asarone extracting solution detection method and system based on a biosensor, and the method sequentially comprises the following steps: mixing medicinal material powder to be detected with an extraction solvent according to a certain solid-to-liquid ratio, and extracting volatile oil by adopting an ultrasonic or reflux method to obtain a crude extracting solution; volatile oil concentrated mother liquor is obtained; obtaining a standard solution; a combined-state electrode is obtained; obtaining electrochemical response data; and converting the electrochemical response data into the content of alpha-asarone in the sample according to the standard curve, and evaluating the precision, the recovery rate and the regeneration performance to obtain a final detection result. Recognition sites prepared by adopting the molecularly imprinted polymer are complementarily paired with template molecules in steric configuration, steric hindrance and key functional groups to realize specific recognition of alpha-asarone, so that false signals caused by matrix interference and non-specific adsorption are remarkably reduced; the electrochemical measurement method is extremely sensitive to electron transfer generated by surface bonding.

The invention discloses construction and application of a biosensor based on an efficient antifouling interface and dual signal amplification, and belongs to the technical fields of optical / electric analytical chemistry, biosensing and material science. According to the invention, the electrode interface is modified with polyaniline doped with polytannic acid as an antifouling film, so that non-specific adsorption of interfering biomolecules in a complex medium is resisted; euTb-MOF is prepared as an efficient luminous body, Tb < 3 + > can transfer energy of Tb < 3 + > and ligand to Eu < 3 + >, and effective signal self-enhancement is realized; according to the EuTb-MOF, the reduction of S2O8 < 2-> is promoted by utilizing the reversible conversion of valence states of Co < 2 + > / Co < 3 + > and Fe < 2 + > / Fe < 3 + > and the synergistic catalysis of Ag NPs, so that the electrochemical luminescence signal of the EuTb-MOF is further improved. Based on the above strategy, the constructed biosensor has high detection sensitivity and precision and long service life, the linear range is 10 fM to 100 nM, and the detection limit is as low as 3.62 fM.

The application discloses a kind of cell membrane chromatographic column based on biotin ligase directional covalent fixation and its preparation method and application, belong to chromatography science and technology field. By bonding 2-imino biotin to silica gel, then using biotin ligase specific recognition with Avi-Tag cell membrane fragments, and stable covalent bonding occurs with 2-imino biotin silica gel, so that cell membrane is fixed on the surface of silica gel to obtain Avi-Tag bridged cell membrane chromatographic stationary phase, finally using wet column packing, obtain cell membrane chromatographic column based on biotin ligase directional covalent fixation. The cell membrane chromatographic column can prolong the service life of cell membrane chromatographic column, improve the stability of cell membrane chromatographic column during use, and the short peptide tag (Avi-Tag) used can improve the non-specific adsorption and poor specificity of the cell membrane chromatographic column prepared based on protein tag technology to a certain extent, providing technical support for the wide application of cell membrane chromatographic column.

The application discloses an acridinium ester labeled complex, which comprises a body, and a labeling group labeled on the body, wherein the body is an antibody, and the labeling group is an acridinium ester group. A preparation method of the acridinium ester labeled complex comprises the following steps: sucking a labeling buffer into a centrifugal tube; sucking an antibody to be labeled into the centrifugal tube and mixing to generate a first mixed solution; adding an acridinium ester solution and mixing, and then performing reaction at 25 DEG C in the dark for 2 hours to generate a second reaction solution; adding a termination buffer and mixing, and then performing reaction at 25 DEG C in the dark for 30 minutes to generate a third reaction solution; performing desalting purification on the third reaction solution to generate a fourth mixed solution; and filtering the fourth mixed solution with a 0.22 mu m filter membrane to generate the acridinium ester labeled complex. According to the preparation method, the labeling efficiency of the acridinium ester and the antibody is higher, the reactivity is stronger, the non-specific adsorption is lower, the sensitivity is higher, the repeatability and stability are better, and the labeling method is simple, rapid and easy to repeat.

The invention relates to the technical field of N sugar chain detection, and particularly discloses an adsorption material for purifying an N sugar chain, a hydrophilic magnetic sphere containing the adsorption material and a kit. The adsorption material for purifying the N sugar chain, provided by the invention, comprises synthesized 1-fluorobetaine acyl chloride hydrochloride which is a hydrophilic molecule and can be connected to a magnetic microsphere through a bonding effect, so that a new hydrophilic magnetic sphere is obtained. The hydrophilic magnetic sphere combined with the hydrophilic molecule can increase the N sugar chain grabbing efficiency of the magnetic sphere and reduce non-specific adsorption to other molecules such as free dye. When being used for N-sugar spectrum detection of an antibody sample, the N-sugar spectrum detection kit is very good in repeatability, precision, linearity and accuracy indexes.

The invention discloses a strong cation exchange chromatography medium as well as a preparation method and application thereof, and belongs to the technical field of biological separation and purification. The structural formula of the strong cation exchange chromatography medium is shown in the specification, the preparation method comprises the following steps: (1) synthesizing epoxy porous polymer microspheres; (2) carrying out an epoxy-sulfydryl click reaction with sulfydryl sulfonate; and (3) hydrolyzing the residual epoxy group to obtain the epoxy resin. The strong cation exchange chromatography medium has the advantages of high protein loading capacity, low non-specific adsorption, good mechanical property and the like, the preparation process is simple, special hydrophilic modification is not needed, and the process is simplified, the industrial production period is shortened and the production cost is reduced under the condition of meeting the conventional protein elution condition. And meanwhile, the high efficiency of the click reaction can meet the characteristics of high loading capacity, good biocompatibility and the like of the chromatography medium.

The invention is applicable to the technical field of biological detection, and provides a method for detecting staphylococcus aureus based on combination of a screen-printed electrode and CRISPR / Cas13a, a probe containing a DNA / RNA hybrid chain is combined with a magnetic bead to form a simple composite structure, when the Cas13a recognizes 16sRNA of S. aureus, trans-cleavage activity can be immediately activated, the probe chain is rapidly cut off, the cut-off amount depends on the activated amount, and when the Cas13a recognizes 16sRNA of S. aureus, the Cas13a can be used for detecting staphylococcus aureus. And after transient magnetic separation, a result is observed on the screen-printed electrode. The method has ultrahigh specificity: the CRISPR / crRNA sequence ensures that staphylococcus aureus and other microorganisms can be accurately distinguished; the trans-cutting of Cas13a provides chemical amplification, and the magnetic separation purification greatly reduces background signals caused by non-specific adsorption, so that the signal-to-noise ratio and the sensitivity are remarkably improved.

This application discloses a chemiluminescence detection kit for acrylonitrile magnetic microparticles and its detection method. The kit includes a magnetic bead working solution and a luminescent label. The magnetic bead working solution includes acrylonitrile monoclonal antibody A and streptavidin. The luminescent label includes acrylonitrile monoclonal antibody B, modified nano-silica, anhydrous toluene, methoxy polyethylene glycol-succinimide ester, N,N-dimethylformamide, acrylonitrile succinimide ester, glutaraldehyde, and ethanolamine. This application uses modified nano-silica as a carrier and grafts a polyethylene glycol hydrophilic layer onto its surface, which amplifies the acrylonitrile ester molecule signal, reduces non-specific adsorption, and improves the sensitivity, specificity, and reliability of the detection.

The application discloses a fast and efficient chemical proteomics sample preparation method, relates to the field of proteomics, and designs and synthesizes agarose microspheres coated with a cleavable linker compound. The free end of the cleavable linker compound contains an azido group, which has good compatibility with existing alkyne probes. Through one-step efficient click chemistry reaction, the probe-labeled peptide segment can be specifically captured on the surface of the agarose microspheres. Since the agarose microspheres and the peptide segment are covalently connected, very strong denaturants or surfactants can be used to wash the medium to remove non-specific adsorption as much as possible. Finally, the probe-labeled peptide segment can be efficiently dissociated from the agarose microspheres through cleavage treatment. The sample preparation method in the application simplifies the cumbersome "click chemistry and streptavidin enrichment" into one-step fast "click chemistry" reaction, and greatly simplifies the operation process.

The invention discloses a magnetic particle chemiluminescence detection kit and a detection method thereof, the kit comprises a magnetic bead working solution and a luminescent marker, the magnetic bead working solution comprises a peptin monoclonal antibody A and streptavidin, the luminous marker is prepared from a peptin monoclonal antibody B, modified nano silicon dioxide, anhydrous toluene, methoxy polyethylene glycol-succinimide ester, N, N-dimethylformamide, acridine succinimide ester, glutaraldehyde and ethanolamine. The acridinium ester molecular signal can be amplified by taking the modified nano silicon dioxide as a carrier and grafting the polyethylene glycol hydrophilic layer on the surface, the non-specific adsorption can be reduced, and the effects of improving the sensitivity, specificity and reliability of detection are achieved.

The present invention provides a particle that shows a small non-specific adsorption, has a reactive functional group for chemically bonding a ligand thereto, and is suitable for an agglutination method. The particle includes a polymer having a unit having a side chain A and a unit having a side chain B, wherein the side chain A has a carboxyl group at a terminal thereof, and has an ester bond and an amide bond in a molecular structure thereof; the side chain B has an alkyl group at a terminal thereof; and a zeta potential at the time when the particles are dispersed in water is minus 40 mV or higher and minus 5 mV or lower.

The invention relates to the technical field of biology, in particular to a magnetic microsphere, a preparation method and application thereof and a reagent containing the magnetic microsphere. The preparation method comprises the following steps: firstly, preparing carboxyl-containing polymer microspheres by a one-step method, then carrying out heat treatment under an alkaline condition, and then carrying out THF oscillation to finally prepare porous polystyrene carboxyl microspheres with uniform pore channels, meanwhile, avoiding using divinyl benzene as a cross-linking agent, reducing the luminous background of the finally obtained magnetic microspheres, and improving the luminous efficiency of the magnetic microspheres. The method can be better applied to the field of chemiluminescence immunoassay. Due to the existence of a surface porous structure and carboxyl, the stability and the functionalization degree of the magnetic material are improved, the problems of magnetic leakage and magnetic shell layer falling are avoided, the surface of the porous ball is smoother and more uniform, and a solid foundation is laid for the subsequent coating process and reduction of non-specific adsorption of the surface of the magnetic ball; the magnetic ball is prepared by using a grinding method, and has the advantages of safety, no toxicity, easiness in operation, no pollution and easiness in industrial popularization.

The present application relates to the field of micro-nano magnetic material for in vitro detection, and particularly relates to a preparation method of high-loading streptavidin magnetic microspheres, the magnetic microspheres and application thereof; in the preparation process, first, streptavidin is reacted with a crosslinking agent to obtain polymerized streptavidin, and then the polymerized streptavidin is coupled on the surface of the magnetic microspheres to obtain streptavidin magnetic microspheres; wherein the structure of the crosslinking agent comprises a hydrophilic flexible chain. The present application has the effects of improving the loading and stability of streptavidin on the surface of the magnetic microspheres, reducing non-specific adsorption, and enhancing the sensitivity of detection.

The application discloses a method for constructing a high-throughput protein capture interface by antibody adsorption, which comprises the following steps: S1, synthesizing a tetrahedral framework nucleic acid structure; S2, mixing a capture antibody and the synthesized tetrahedral framework nucleic acid structure on a gold island substrate to prepare a high-throughput protein capture interface; S3, placing the gold island substrate in a wet box for overnight incubation; S4, blocking the capture interface to prevent non-specific adsorption; S5, incubating a protein target; S6, incubating a detection antibody; S7, incubating a fluorescent secondary antibody; S8, washing the capture interface with pure water and centrifuging and air-drying; and S9, performing fluorescent imaging and quantification on the capture interface by using a chip scanner. The method for constructing a high-throughput protein capture interface by antibody adsorption has high uniformity, and can realize high-throughput, high-sensitivity and high-accuracy protein capture and quantitative detection.

This invention discloses a field-effect transistor biosensor based on a framework nucleic acid-gold nanoparticle composite structure and its fabrication method, comprising the following steps: 1) providing a carbon nanotube field-effect transistor substrate; 2) depositing a hafnium oxide dielectric layer on the surface of the carbon nanotube channel; 3) depositing gold nanoparticles on the surface of the hafnium oxide dielectric layer; 4) preparing a tetrahedral framework nucleic acid probe; 5) adding the probe solution to the surface of the gold nanoparticles for incubation and fixation; 6) sealing unreacted sites on the surface of the gold nanoparticles and washing with buffer solution. This invention achieves precise interface modification through atomic layer deposition, electron beam evaporation, and gold-sulfur bond anchoring. It utilizes the rigid structure of the tetrahedral framework nucleic acid to achieve precise, directional, and spaced probe distribution, effectively overcoming Debye shielding limitations and reducing non-specific adsorption. The sensor exhibits ultra-high sensitivity, excellent stability and reusability, strong specificity, and good versatility, and can be used for highly sensitive and specific detection of various targets such as nucleic acids and proteins.

The application discloses a reagent containing pig pseudorabies virus gB protein magnetic microparticle coating, a preparation method and a kit, and relates to the technical field of antibody detection. The preparation method of the reagent containing pig pseudorabies virus gB protein magnetic microparticle coating comprises the following steps: incubating magnetic microparticles and gB protein antibodies in a coating buffer solution; removing the reaction solution, and performing first sealing on the gB protein magnetic microparticle coating with a first sealing solution; after the first sealing is completed, the first sealing solution is washed away, and then the gB protein magnetic microparticle coating is sealed for the second time with a second sealing solution; after the second sealing is completed, the second sealing solution is washed away, and then resuspension is performed to obtain the reagent containing the gB protein magnetic microparticle coating. The two-step sealing method is adopted to prepare the reagent containing the pig pseudorabies virus gB protein magnetic microparticle coating, the sealing effect is good, and non-specific adsorption in the system is reduced. The kit provided by the application contains the reagent, and has the advantages of high analysis sensitivity, a wide linear range and high accuracy.

The application provides a Bola type surfactant-based blocking agent, which can be used for modifying various object surface materials, especially the surface of a carrier material for immune diagnosis, so that the non-specific adsorption of the carrier material is reduced, and the sensitivity and signal-to-noise ratio of a reagent are improved. Compared with traditional blocking agents, the Bola type surfactant-based blocking agent provided by the application not only has the excellent characteristics of traditional surfactant blocking agents, but also has increased repulsion to non-specific molecules and more compact blocking due to the rigid hairpin structure after combination.

This invention discloses a magnetic fluorescently imprinted nanoparticle, its preparation method, and its application. The nanoparticle comprises amino-functionalized magnetic nanoparticles and a fluorescently imprinted polymer layer coated on their surface, wherein the fluorescently imprinted polymer layer has an imprinted cavity; the imprinted molecule in the fluorescently imprinted polymer layer is a cTnI-specific C-terminal epitope peptide. Functional monomers are screened using computational chemistry, and nanomolecularly imprinted polymers (MIPs) are synthesized using epitope imprinting technology. Fluorescent monomers are introduced to impart autofluorescence response properties, forming a label-free detection system. These nanoparticles exhibit highly efficient adsorption and specific recognition of cTnI protein, with a detection sensitivity of 1 pg / mL (R²=0.98). They show extremely low non-specific adsorption to common interfering proteins and effectively resist interference from complex biological matrices, providing a new approach for rapid clinical cTnI detection.

This invention discloses a flotation separation method for removing talc from molybdenite using sodium alginate sulfate. The method involves preparing a raw slurry from talc-type molybdenite, controlling the pH of the slurry to be 6.0–10.0. Sodium alginate sulfate is added to the slurry and stirred. Then, an anisopolar collector is added and stirred to condition the slurry. A frother is then added to obtain a mixed slurry. Finally, the mixed slurry is subjected to aerated flotation. The collected frothy product is the molybdenum concentrate, and the product in the tank is the talc-containing tailings. This invention, by adding sodium alginate sulfate (SAS), which has high electronegativity and strong chelating ability, as a specific inhibitor to the flotation system, blocks the contact between the collector and talc. Simultaneously, its strong electrostatic repulsion effectively prevents non-specific adsorption on the negatively charged molybdenite surface. This invention significantly improves the grade and recovery rate of molybdenum concentrate and has extremely high industrial promotion and engineering application value.

The invention relates to the technical field of environmental pollutant detection, and discloses a preparation method of a fluorescent probe for detecting polycyclic aromatic hydrocarbon in industrial wastewater, and the preparation method comprises the following steps: dissolving a carbon source substance and a nitrogen source substance in deionized water to form a mixed solution; transferring the mixed solution into a hydrothermal reaction kettle for heat treatment to obtain a nitrogen-doped carbon quantum dot initial product; and dialyzing and purifying the head product to obtain the purified nitrogen-doped carbon quantum dots. A specific recognition cavity which is complementary with a polycyclic aromatic hydrocarbon molecular space structure, size and functional group is constructed on the surface of the carbon quantum dot through a molecular imprinting technology, and the imprinting layer endows the probe with excellent molecular selectivity; benzene series, heavy metal ions and anionic surfactant interfering substances coexisting in the industrial wastewater are difficult to enter an imprinting cavity due to size mismatching or acting force difference, so that non-specific adsorption is remarkably reduced, and the detection accuracy and the anti-interference capability are improved.

The application discloses a one-step monoclonal antibody drug electrochemical detection biosensor and a preparation method and application thereof. The application designs and screens an affinity specific DNA aptamer hairpin probe and uses the same as a specific capture unit, then uses a gold-sulfur bond to fix the DNA aptamer hairpin probe on a screen-printed electrode surface, meanwhile, uses a self-assembly interaction between a metal and a mercapto group to fix a blocking agent introduced on the screen-printed electrode surface, and blocks the excess electrode surface reaction sites, so that the one-step monoclonal antibody drug electrochemical detection biosensor is obtained. The one-step monoclonal antibody drug electrochemical detection biosensor has the advantages of simple operation, high sensitivity, less non-specific adsorption, high capture efficiency, stable physical and chemical properties, strong specificity and good selectivity, and can be used for capturing antibody drugs in complex biological samples.

This invention discloses a chemiluminescent immunoassay method, comprising the following steps: labeling disulfide-bonded biotin or desulfobiotin onto affinity ligand one to form complex one; labeling a luminescent compound onto affinity ligand two to form complex two; mixing the sample with a solid-phase carrier containing complex one, complex two, and streptavidin-coupled compound to form an immunosandwich complex; processing the immunosandwich complex to release the immunosandwich complex from the solid-phase carrier; separating the immunosandwich complex from the solid-phase carrier; detecting the total luminescent signal value of the separated immunosandwich complex; and calculating the concentration of the analyte based on the total luminescent signal value. This invention releases the immunosandwich complex from the solid-phase carrier, uses a magnetic field to attract the solid-phase carrier, and measures the supernatant of the released immunosandwich complex. Solid-phase carriers containing non-specific adsorption cannot enter the measurement chamber, completely eliminating the problem of non-specific adsorption on the surface of magnetic beads.

The invention relates to an extracellular vesicle enrichment material as well as preparation and application thereof. According to the enrichment material, SPP serves as a monomer, AIBN serves as an initiator, and a hydrophilic amphoteric high-molecular polymer is prepared through a precipitation polymerization reaction. The efficient capture of the extracellular vesicles is realized by utilizing the coordination effect of the prepared amphoteric high-molecular polymer and phosphatidylcholine on the surfaces of the extracellular vesicles. Meanwhile, the material is subjected to phase change centrifugation in an organic phase with a certain concentration to form a precipitate, and one-step efficient enrichment of the extracellular vesicles is realized by utilizing the characteristic. The material contains repeated amphoteric group units, so that the material has strong affinity to extracellular vesicles, and meanwhile, the strong hydrophilicity of the material can also avoid non-specific adsorption of impure proteins, so that the enrichment purity of the extracellular vesicles is remarkably improved. In addition, the material has the advantages of being easy to prepare, simple and convenient to operate, efficient in enrichment and the like, and has important significance on separation and purification and downstream analysis of extracellular vesicles in body fluid.

The invention discloses high-rigidity agarose microspheres and a preparation method thereof.The preparation method comprises the steps that alkenyl modified polysaccharide is compounded in an agarose matrix, diene monomers are added, and a high-strength three-dimensional cross-linked network is constructed in the microspheres through two-step free radical polymerization and serves as a framework in the agarose microspheres; external epoxy crosslinking is combined, and the rigidity of the agarose microspheres is improved through internal and external synergism, so that the agarose microspheres can tolerate higher operation pressure and flow velocity; according to the preparation method, the agarose does not need to be modified in advance, the agarose microspheres do not need to be subjected to multi-step crosslinking, the preparation process is simple, the dosage of an organic solvent is reduced, the emission of organic matters is reduced, and the production process is more environment-friendly; the microspheres are composed of agarose and hydrophilic polysaccharide, and non-specific adsorption is low.

The invention belongs to the field of membrane separation technology and bioengineering, and particularly relates to an anti-pollution composite nanofiber membrane for high-precision and high-flux separation of protein and a preparation method of the anti-pollution composite nanofiber membrane. According to the separation membrane, a hydrophilic polymer and zwitterionic polymer blended nanofiber membrane prepared through electrostatic spinning serves as a base material, zwitterionic polymers are grafted to the surfaces of fibers through the surface-initiated atom transfer radical polymerization (ATRP) technology, and a separation functional layer with excellent anti-pollution performance is formed. According to the invention, non-specific adsorption of protein and membrane pollution are effectively inhibited by constructing a high-density hydration layer, and the membrane has high porosity and high connectivity of a nanofiber-based membrane and super-hydrophilic and anti-pollution characteristics of a zwitterionic layer at the same time. The composite membrane has high selectivity, high rejection rate and excellent cycling stability on target protein in complex biological samples (such as serum, cell lysis buffer and fermentation liquor), and solves the problems that a traditional polymer membrane is easy to pollute, low in efficiency and poor in precision in protein separation.

The invention is applicable to the technical field of electrochemistry, and provides a peptidyl electrochemical biosensor and a preparation method and application thereof, the peptidyl electrochemical biosensor is obtained by fixing delta-modified polypeptide on a glassy carbon electrode; the glassy carbon electrode is obtained by sequentially modifying 3, 4-ethylenedioxythiophene doped with sodium alginate and gold nanoparticles on a bare glassy carbon electrode. The delta-modified polypeptide can effectively prevent non-specific adsorption of biomolecules and degradation of protease, and when the delta-modified polypeptide is applied to detection of a disease marker human annexin A1, the delta-modified polypeptide resists non-specific adsorption in complex biological fluid and biodegradation of protease; accurate and reliable detection of the target ANXA1 is realized by using the current signal change before and after the aptamer sequence designed at the terminal of the polypeptide is combined with the target, and the aptamer has the advantages of simplicity in operation, high sensitivity, good selectivity and good anti-adsorption effect, and is proved to have higher accuracy in clinical serum analysis.