30 results about "Oxygenase activity" patented technology

The invention belongs to the technical field of catalyst materials, and particularly relates to a catalyst material integrated with Au-Ir cascade catalytic sites as well as a preparation method and application of the catalyst material. The catalyst material comprises micron-sized urchin-like carbonaceous particles loaded with cascaded Au clusters and Ir monatomic materials, and the micron-sized urchin-like carbonaceous particles have glucose oxidase-like activity, oxidases-like activity, peroxidase-like activity and NADH oxidase-like activity, so that metabolic inhibition can be combined with reactive oxygen attack to eliminate stubborn dental caries related biological membranes.

The invention relates to a preparation method of manganous-manganic oxide / graphite nano-enzyme for sensitive detection of L-cysteine, a green synthesis strategy is adopted, a mechanochemical method is combined to develop a novel Mn3O4 / graphite composite material which is low in cost, high in activity and easy to synthesize in macroscopic quantity, and the prepared product has relatively high catalytic activity and can be applied to the detection of L-cysteine. Compared with the prior art, the method has the advantages that oxidase-like activity is obviously improved, the Michaelis constant Km is 0.132, the maximum reaction rate Vmax is 0.998 * 10 <-7 > M <-1 > s, high-sensitivity and visual analysis and detection of L-Cys can be realized at normal temperature, the detection interval is 1-40 [mu] mol / L, and the detection limit is 0.361 [mu] mol / L.

The present invention relates to novel enzyme nanoparticles capable of converting methane into methanol, in which key active sites of methane-oxidizing bacteria are fused with each other and expressed on a protein that can be self-assembled in cells to form nanoparticles, and specifically to enzyme nanoparticles including a protein having methane monooxygenase (MMO) activity and active sites of the methane oxidase, a method for production thereof, a recombinant microorganism into which a nucleic acid encoding the protein and the active site of the methane oxidase is introduced, and immobilized enzyme nanoparticles including the enzyme nanoparticles loaded on a carrier.

The present application relates to the field of plant genetic breeding, and particularly relates to a kind of evaluation method of asparagus yield. Including the following steps: S1, obtaining young plant period asparagus;S2, measures i variety of young plant period asparagus following parameters: photosynthetic rate A, ribulose-1,5-bisphosphate carboxylase / oxygenase activity B, leaf dry weight per unit area C, acid invertase activity D and root crown ratio E;The measurement sample of the acid invertase activity D is the tender stem of young plant period asparagus at 10-30cm from top;S3, according to the formula, the evaluation value is calculated, and the evaluation value is used to evaluate the yield of asparagus. The evaluation value obtained by using the above measurement index and calculation formula, and the significance level obtained by SPSS software is used to evaluate the yield of asparagus. The yield potential of asparagus can be comprehensively evaluated from the genetic point of view in a short time. Using the evaluation method of the present application, high-yield asparagus varieties can be selected in a short time without tracking for many years.

The present application relates to the technical field of detection, and relates to a preparation method of an oxygen-rich vacancy Mn3O4 nanoscale enzyme, and the method comprises the following steps: step one: adding KMnO4 into deionized water according to a ratio of 0.5-1.5 g:500 ml, and completely dissolving to obtain a mixed solution; step two: adding oleic acid according to a volume ratio of 1:50, and continuously stirring at 25-35 DEG C for 4-6 hours; step three: collecting the precipitate, washing with deionized water and ethanol alternately for 4-6 times, drying at 70-90 DEG C for 8-12 hours, and calcining at 180-220 DEG C for 4-6 hours, so as to obtain an oxygen-rich vacancy Mn3O4 nanoscale enzyme with oxidase activity; and the oxygen-rich vacancy Mn3O4 nanoscale enzyme can detect nitrite rapidly, sensitively and specifically.

The application is suitable for the field of analog enzyme technology, and provides a light-controlled zein-based dual-enzyme-activity analog enzyme and a preparation method thereof.The preparation method comprises the following steps: under water bath conditions, dissolving zein in an alkaline aqueous solution and incubating; adding a hydroxylamine solution to the solution obtained in step S1 and continuing to react; and after the reaction is completed, obtaining the light-controlled zein-based dual-enzyme-activity analog enzyme.The application uses zein as a raw material, is modified by hydroxylamine, does not need any metal component to participate, has light-controlled switchable dual-enzyme activity, exhibits oxidase-like activity under visible light irradiation, presents peroxidase-like activity in dark conditions, and can realize reversible switching of the two enzyme activities by regulating light, effectively overcomes the problems that traditional artificial analog enzymes depend on metal ions, multiple enzyme activities coexist, interfere with each other and are difficult to accurately control, can be used for colorimetric detection of total antioxidant capacity, can be used for colorimetric detection of glucose in cascade reaction with glucose oxidase, has the advantages of simple operation, rapid response, high sensitivity, good selectivity, low cost and the like, and has a good application prospect in the fields of food analysis, clinical diagnosis and the like.

The invention belongs to the technical field of nano-catalyst antibiosis, and particularly relates to a zinc-based nitrogen-doped carbon-loaded metal palladium nano-enzyme as well as a preparation method and application thereof. The ZnNC-loaded metal palladium nano-enzyme is prepared by adopting a deposition-precipitation method which is simple to operate, taking ZnNC as a carrier and taking metal palladium nano-particles as an active center. The nano-enzyme has excellent oxidase-like activity, can catalyze O2 to generate hydroxyl free radicals (. OH), singlet oxygen (< 1 > O2) and superoxide anion free radicals (O2 <->) so as to kill bacteria and achieve an antibacterial effect, and has a remarkable antibacterial effect on escherichia coli under an acidic condition.

To provide a protein switch that can be used to determine a level of an analyte that is diagnostic of health and / or well-being of a subject.SOLUTION: A protein switch comprises at least one non-naturally occurring polypeptide including: (a) at least one analyte-binding domain capable of binding to at least one analyte; and (b) at least one oxidase domain or dehydrogenase domain having oxidase activity or dehydrogenase activity and capable of binding to or reacting with at least one reactant, where (i) the analyte that binds to the analyte-binding domain is different from the reactant that binds to or reacts with the oxidase domain or dehydrogenase domain; and (ii) the oxidase activity or dehydrogenase activity is altered when the analyte binds to the analyte-binding domain.SELECTED DRAWING: None

This invention provides a method for detecting vitamin C based on oxidase-active nanozymes. The method includes: preparing a first mixture of MnO2@MIP nanozyme, TMB solution, HAc-NaAc buffer, and the sample to be tested; and a second mixture of MnO2@MIP nanozyme, TMB solution, HAc-NaAc buffer, and vitamin C at different concentration gradients; reacting the first and second mixtures under the same predetermined reaction conditions; measuring the absorbance of the products after the reaction at predetermined wavelengths, corresponding to absorbance values ​​A1 and A0, respectively; obtaining a linear regression equation based on A0 and vitamin C at different concentration gradients; and determining the vitamin C content in the sample to be tested based on the linear regression equation and A1. The provided method is rapid and has extremely high sensitivity.

This invention belongs to the fields of nanomaterial preparation, enzyme engineering, and biosensing technology. It discloses a ligand-guided in-situ synthesis of nickel-manganese hybrid nanozymes, its preparation method, and applications. Based on a MOF precursor liquid-phase in-situ evolution strategy, using 2-methylimidazole as a structure-directing agent and nucleation initiator, a controlled coordination-hydrolysis competitive reaction is induced between divalent manganese salt and divalent nickel salt in a mild aqueous system, resulting in a one-step synthesis of nickel-doped manganese tetroxide (Ni-Mn3O4) hybrid nanospheres with surface-modified organic ligands. The obtained nanozyme exhibits a uniform spherical morphology (approximately 100 nm in diameter), excellent dispersibility, and, thanks to its robust oxide framework, demonstrates superior structural stability and oxidase-like activity in an acidic catalytic environment at pH 4.0. Based on this nanozyme, a highly sensitive, wide-linear-range colorimetric screening platform for α-glucosidase inhibitors was constructed. The method of this invention is simple and environmentally friendly, requiring no high-temperature calcination.

The application belongs to the technical field of nano-enzyme sensing, and particularly relates to a three-mode phytic acid detection method based on a double-enzyme cascade reaction and application thereof. The detection method uses CAU-10-NH2 metal organic framework as a light-responsive nano-enzyme, combines the light catalytic oxidase activity of ALP and CAU-10-NH2, acquires signals through three modes of fluorescence spectrum, ultraviolet-visible absorption spectrum and photothermal imaging, and quantitatively analyzes the phytic acid content according to the signal change. Phytic acid inhibits the ALP activity, controls the generation amount of ascorbic acid, further influences the oxTMB content generated by CAU-10-NH2 catalyzing TMB oxidation, and realizes the synchronous change of fluorescence, colorimetric and photothermal signals. The application first discovers that CAU-10-NH2 has light catalytic oxidase activity, and only the -NH2 substituted derivative in the CAU-10 series (including CAU-10-H, -OH, -Br, -NO2, etc.) exhibits the activity, which expands the application of aluminum-based MOFs in the field of nano-enzyme sensing.

The application discloses a respiratory burst oxidase gene StoRBOHB and application of the gene in resistance of Solanum torvum to verticillium wilt, wherein a nucleotide sequence of the StoRBOHB gene is shown as SEQ ID NO. 1, the StoRBOHB gene is induced to express by Lecanicillium dimidiatum, is highly expressed in roots, and responds to ABA, MeJA and SA hormone signals, the gene encodes a protein located on a cell membrane; the StoRBOHB is silenced through a VIGS technology, which significantly reduces the resistance of Solanum torvum to verticillium wilt, and is manifested as that a disease index is increased, H2O2 accumulation is reduced, antioxidant enzyme activity is reduced, and lignin deposition is reduced; and overexpression of the gene enhances the above-mentioned defense response, and overexpression of the StoRBOHB in transgenic Arabidopsis also shows that the resistance to verticillium wilt is significantly improved; the application provides a new gene resource and application scheme for molecular breeding of eggplant resistance to verticillium wilt, and has a wide application prospect in the field of agricultural biotechnology.

The application relates to the technical field of biosensors, and discloses a metal nucleic acid framework nanocascade enzyme as well as a preparation method and application thereof. The preparation method of the nanocascade enzyme is as follows: nucleotide sequences shown in SEQ ID NO. 1-10 are mixed in an equimolar ratio, annealing reaction is carried out to obtain a metal template DNA nanosheet; the DNA nanosheet is reacted with a metal precursor to obtain the metal nucleic acid framework nanocascade enzyme. The metal nucleic acid framework nanocascade enzyme DNS-Fe has catalase activity, after corresponding aptamers are added, the DNS-Fe can accurately recognize target objects in various interferents, and the accuracy is high; DNS-Pt / Fe has lactic acid oxidase, glucose oxidase and sarcosine oxidase activity; DNS-Ag / Fe has uric acid oxidase activity; the combination of the DNS-Fe and the DNS-Ag / Fe can realize cascade action, replace natural catalase to catalyze hydrogen peroxide to generate free radicals, and the free radicals are reacted with chromogenic substances to generate a color reaction, and the results are easy to observe.

The application belongs to the technical field of catalyst materials, and particularly relates to a catalyst material integrated with Au-Ir cascade catalytic sites and a preparation method and application thereof. The catalyst material comprises micron-scale urchin-like carbonaceous particles loaded with cascade Au clusters and Ir monatomic material, has glucose oxidase-like activity, oxidase-like activity, peroxidase-like activity and NADH oxidase-like activity, and can combine metabolic inhibition and active oxygen attack to eliminate stubborn caries-related biofilms.

Enzymes having hydrolase, decarboxylase and Baeyer-Villiger oxidase activity are isolated from the black yeast-like fungus Exophiala sp. strain LRDC-1. The enzymes catalyze the degradation of resorcylic acid lactone mycotoxins such as zearalenone, and are useful in methods of detoxifying material contaminated with these mycotoxins.

The invention belongs to the technical field of nano biomedicine and enzyme engineering, and discloses a preparation method of a monatomic enzyme with glutamate decarboxylase-like activity and multiple antioxidant enzyme activity. The monatomic enzyme comprises an atomic-scale dispersed iron active center and a nitrogen and phosphorus co-doped carbon matrix carrier, the coordination environment of the iron active center is Fe-P1N3, glutamic acid can be catalyzed to be converted into gamma-aminobutyric acid, and the monatomic enzyme has superoxide dismutase-like activity, hydroxyl free radical scavenging capacity and catalase-like activity. According to the invention, the simulation of the monatomic enzyme on complex biological catalytic functions such as amino acid conversion and neurotransmitter synthesis is realized for the first time, high-selectivity and high-efficiency catalytic reaction is realized through a unique Fe-P1N3 coordination structure, and the monatomic enzyme has important application value in the fields of neurotransmitter regulation and oxidative stress protection.

The application relates to a PtRhRuCu quaternary alloy nanoscale enzyme and a preparation method and application thereof, relates to the field of catalytic materials and analytical chemistry, and the quaternary alloy nanoscale enzyme is a nanoparticle composed of Pt, Rh, Ru and Cu and having an isolated island-shaped structure. The preparation method of the PtRhRuCu quaternary alloy nanoscale enzyme comprises the following steps: S1, mixing K2PtCl4 solution, K3RhCl6 solution, RuCl3 solution and CuCl2 solution to obtain a mixed solution I; S2, adding polyvinylpyrrolidone powder to the mixed solution I while stirring, heating to 150-220 DEG C, and constant-temperature reaction for 6-8 hours to obtain a mixed solution II; and S3, cooling the mixed solution II to room temperature, centrifuging, washing, separating out solid precipitates, and freeze-drying to obtain the PtRhRuCu quaternary alloy nanoscale enzyme. The application introduces the transition group metal element Cu into the three noble metals Pt, Rh and Ru, causes a multi-element effect, significantly improves the peroxidase-like activity, inhibits the oxidase-like activity, and achieves the effect of "directional regulation" of catalytic activity.

The invention relates to the technical field of plant physiological regulation and control and heavy metal pollution treatment, and provides a regulation and control method for applying xanthine from an external source aiming at plant oxidative damage and growth inhibition caused by Sn < 4 + > and the limitation that an existing treatment technology is high in cost and easy to cause secondary pollution or does not resist stress from plant endogenous metabolism. According to the method, xanthine is applied to a duckweed and arabidopsis thaliana culture system, the activity of antioxidant enzymes such as SOD, POD and CAT can be activated, MDA accumulation is inhibited, a photosynthetic system is repaired, and related genes of a xanthine metabolic pathway are activated. Experiments show that the growth recovery rate of the duckweed root system reaches 96%, and the elongation of the arabidopsis root system is increased by 120%; the Fv / Fm of the duckweed is increased by 152%, the ETR is increased by 72.7%, and the YNO is reduced by 42.8%; the activity of the arabidopsis thaliana antioxidant enzyme is recovered to be normal, MDA is reduced by 42%, ROS metabolic balance and photosynthetic restoration are synchronously achieved, and a low-cost and environment-friendly technology is provided for water heavy metal treatment and agricultural stress resistance.

The invention discloses an Escherichia coli colorimetric detection method established based on aptamer enhanced octahedral Ag2O nanoparticle simulation oxidase activity, which is characterized by comprising the following steps: (1) fully and uniformly mixing dispersion liquid of octahedral Ag2O NPs and P12-55 aptamer solution, and then incubating; (2) adding a test sample into the mixed solution, and continuing incubation; and (3) adding TMB and a NaAc buffer solution, carrying out ultraviolet / visible spectrum analysis at room temperature, recording absorbance values of the test sample and the blank sample at 652nm, and calculating the change of the absorbance values to obtain a detection result.

The invention belongs to the technical field of synthesis and application of monatomic nano-enzymes, and particularly relates to a sulfur-doped iron monatomic nano-enzyme, a preparation method and application of the sulfur-doped iron monatomic nano-enzyme in 5-hydroxytryptamine detection. The sulfur-doped iron monatomic nano-enzyme is composed of a matrix and an active coordination structure, the matrix is porous carbon, the active coordination structure is FexNSy, x and y are molar ratios of elements, and x: y = 1; the sulfur and the nitrogen are doped in the matrix, and the iron is dispersed in the matrix in an atomic-scale structure. The sulfur-doped iron monatomic nano-enzyme has excellent oxidase-like activity, can catalyze a chromogenic reaction under the condition of no hydrogen peroxide, and can realize high-selectivity and high-sensitivity detection of 5-HT when being used as a catalyst in the detection of 5-HT.

This invention discloses a composite hydrogel with pH-responsive dual-enzyme activity switching properties, its preparation method, and its applications, belonging to the field of wound healing materials technology. The composite hydrogel comprises a nanozyme and a hydrogel. The nanozyme is a gold-platinum nanozyme, which is porous and dendritic, exhibiting different enzyme-like activities under different pH conditions. In an acidic environment, it exhibits oxidase-like and peroxidase-like activities, while in a neutral environment, it exhibits superoxide dismutase-like and catalase-like activities. This invention can exhibit reversibly switchable multi-enzyme mimicry activities under different pH conditions, thereby achieving dynamic synergistic regulation of antibacterial and antioxidant effects, overcoming the problem of difficulty in simultaneously achieving both in existing technologies. Furthermore, this invention has good biocompatibility, adhesion, and sustained-release properties, enabling adaptive functional regulation at different stages of wound healing, significantly promoting chronic wound healing and tissue repair, and showing promising clinical application prospects.

The present application relates to a kind of synthesis method and application of betaine-derived carbon quantum dots, first, betaine and amaranth red are used to generate carbon quantum dots stock solution by hydrothermal reaction, the stock solution is filtered, dialysis, freeze-drying, and carbon quantum dots powder is obtained.Second, a certain concentration range of carbon quantum dots solution is configured, and the antioxidant enzyme activity of betaine-derived carbon quantum dots is detected.Then, with zebra fish hypercholesterolemia model as an example, betaine-derived carbon quantum dots solution is applied to the treatment of zebra fish hypercholesterolemia model, and the mouse hyperlipidemia model is verified.Finally, in hepatocyte system, it is found that betaine-derived carbon quantum dots are through inhibiting PCSK9 to play the role of lowering blood lipid.The present application is not only an antioxidant enzyme with catalase activity, but also can reduce total cholesterol and total triglyceride in hypercholesterolemia by inhibiting PCSK9, and relieve liver steatosis.It has higher use value and application prospect.

The invention provides a metal monatomic nano enzyme and application thereof. The metal monatomic nano-enzyme comprises graphene, a nitrogen atom and a metal monatomic, the metal monatomic is anchored on the graphene through the nitrogen atom, and a metal-nitrogen active site is formed. The nano-enzyme disclosed by the invention has relatively high NADH oxidase-like activity, so that the nano-enzyme plays a role in improving dermatitis and promoting skin regeneration or healing.

The invention provides a ternary complex dual-mode probe and an acetylcholin esterase activity and enzyme inhibitor detection method thereof. The ternary complex dual-mode probe is composed of a CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) system, a manganese dioxide nanoflower-CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) activated ssDNA (ssDNA) (MnO2 NFs-ssDNA) and internal reference fluorescence. When a target to be detected is acetylcholin esterase (AChE), hydrolysis of an acetylthiocholine substrate can be catalyzed, a thiocholine product can be generated, MnO2 NFs can be decomposed to release ssDNA, the trans-cleavage activity of Cas12a can be activated, fluorescence report nucleic acid can be cleaved, a fluorescence signal can be generated, and a more accurate ratio fluorescence signal can be output by taking internal reference fluorescence added into a system as an internal standard; the decomposition of the MnO2 NFs reduces the oxidase-like activity of the MnO2 NFs, and the colorimetric signal for catalyzing the color development of 3, 3 ', 5, 5'-tetramethyl benzidine is reduced; therefore, the higher the AChE activity is, the larger the yield of the thiocholine is, the more thorough the decomposition of the MnO2 NFs is, the stronger the fluorescence signal is, and the weaker the colorimetric signal is. The enzyme inhibitor organophosphorus pesticide can inhibit generation of thiocholine, and then an opposite experiment result appears.

The invention discloses an MFN1 engineered mitochondrial vesicle and an application of the MFN1 engineered mitochondrial vesicle in preparation of an anti-cell aging drug. The MFN1 engineered mitochondrial vesicles are prepared by the following steps: firstly, constructing an overexpression vector of an MFN1 gene, transfecting cells, obtaining a cell line of the overexpressed MFN1 gene, culturing, collecting a culture solution, and separating and extracting mitochondrial vesicles, so as to obtain the MFN1 engineered mitochondrial vesicles MFN1-MDVs rich in mtDNA. The MFN1-MDVs is used for treating senescent cells caused by mitochondrial dysfunction, and the result shows that the MFN1-MDVs can be internalized into the senescent cells, so that the mtDNA and ATP content of senescent cell mitochondria is effectively improved, the oxidative phosphorylation level is improved, the antioxidant enzyme activity of the senescent cells is enhanced, ROS is reduced, the mitochondrial membrane potential is recovered, and finally the mitochondrial network structure is improved. The obvious mitochondrial function repairing potential and the cell senescence improving effect are shown.

The present application relates to the preparation method of nanoparticles with oxidase-like activity and its products and applications, and belongs to the technical field of phenylenediamine isomer recognition. The present application mainly adopts ZIF-8, Ce 3+ , M 3+ (Eu 3+ , Fe 3+ or Co 3+ ) and Mn-CDs to react, so as to obtain nanoparticles with oxidase-like activity. The nanoparticles prepared by the present application have good oxidase-like activity, and can be applied to catalyze the oxidation reaction of OPD, MPD and PPD, so as to obtain yellow, colorless and purple oxidation products respectively. Therefore, according to the color of the oxidation product formed by the catalysis of the nanoparticles with oxidase-like activity on the oxidation of phenylenediamine, a colorimetric method for identifying and detecting OPD, MPD and PPD is established, which has the characteristics of low cost, high sensitivity, simple operation and high selectivity, and has good application prospect in the detection of OPD and PPD in environmental water samples.

This invention discloses an MFN1-engineered mitochondrial vesicle and its application in the preparation of anti-cellular aging drugs. The MFN1-engineered mitochondrial vesicle is first constructed by... MFN1 Gene overexpression vectors are used to transfect cells and obtain overexpression. MFN1 Cell lines containing the gene were cultured, culture medium was collected, and mitochondrial vesicles were isolated and extracted to obtain MFN1-MDVs, engineered mitochondrial vesicles rich in mtDNA. MFN1-MDVs were used to treat senescent cells caused by mitochondrial dysfunction. Results showed that MFN1-MDVs could be internalized into senescent cells, effectively increasing mitochondrial mtDNA and ATP content, enhancing oxidative phosphorylation levels, increasing antioxidant enzyme activity and reducing ROS, restoring mitochondrial membrane potential, and ultimately improving mitochondrial network structure, demonstrating significant potential for mitochondrial function repair and improvement of cell senescence.

The invention relates to the technical field of detection, in particular to a preparation method of oxygen vacancy-enriched manganous-manganic oxide nano-enzyme, which comprises the following steps: step 1, adding KMnO4 into deionized water according to a ratio of (0.5-1.5) g: 500ml, and completely dissolving to obtain a mixed solution; 2, adding oleic acid according to the volume ratio of oleic acid to deionized water of 1: 50, and continuously stirring for 4-6 hours at 25-35 DEG C; and 3, collecting the precipitate, alternately washing with deionized water and ethanol for 4-6 times, drying at 70-90 DEG C for 8-12 hours, and calcining at 180-220 DEG C for 4-6 hours to obtain the oxygen-vacancy-rich Mn3O4 nano-enzyme with oxidase-like activity. The oxygen-vacancy-rich Mn3O4 nano-enzyme can be used for rapidly, sensitively and specifically detecting nitrite.

The present invention includes a step of incubating a protein having NADH and / or NADPH oxidase activity together with NADH and / or NADPH in an aqueous solution, wherein NADH is converted to NAD + to and / or NADPH to NADP + A method for oxidation, wherein the protein comprises an amino acid sequence selected from the group consisting of the following, relating to the method i) An amino acid sequence having at least 80% sequence identity with Sequence ID No. 1, ii) an amino acid sequence encoded by a nucleic acid sequence having at least 80% identity with SEQ ID NO: 2, and iii) an amino acid sequence encoded by a nucleic acid that binds to a nucleic acid molecule complementary to the nucleic acid sequence of SEQ ID NO: 2 under stringent conditions, wherein stringent conditions preferably include washing at 65°C and with a salt concentration of 0.1 to 2 × SSC.

The invention relates to the technical field of biosensors, and discloses a metal nucleic acid framework nano cascade enzyme as well as a preparation method and application thereof. The preparation method of the nano cascade enzyme comprises the following steps: mixing nucleotide sequences as shown in SEQ ID NO.1-10 according to an equal molar ratio, and carrying out annealing reaction to obtain a DNA nanosheet of a metal template; and reacting the DNA nanosheet with a metal precursor to obtain the metal nucleic acid framework nano cascade enzyme. The metal nucleic acid framework nano cascade enzyme DNS-Fe has catalase activity, and after a corresponding aptamer is added, a target object can be accurately recognized in a plurality of interferents, and the accuracy is high; dNS-Pt / Fe has the activity of lactate oxidase, glucose oxidase and sarcosine oxidase, and DNS-Ag / Fe has the activity of urate oxidase, so that the cascade action can be realized by combining the DNS-Pt / Fe with the DNS-Fe, and the DNS-Ag / Fe replaces natural catalase to catalyze hydrogen peroxide to generate free radicals to be subjected to chromogenic reaction with a chromogenic substance, and the result is easy to observe.