65 results about "Kanamycin" patented technology

The invention relates to a norhalal-enoxacin conjugate as well as a preparation method and application thereof. The norhalal-enoxacin conjugate comprises a norhalal-enoxacin coupling compound, or a stereoisomer, a prodrug, a crystal form, a pharmaceutically acceptable salt, a pharmaceutically acceptable ester or a pharmaceutically acceptable solvate selected from the compound. Compared with enoxacin, kanamycin, streptomycin, lincomycin and azithromycin, the norharmann-enoxacin conjugate disclosed by the invention has a smaller MIC (Minimum Inhibitory Concentration) value, which shows that the norharmann-enoxacin conjugate has a better anti-staphylococcus aureus effect.

The invention provides bacillus velezensis and an application of the bacillus velezensis in degradation of antibiotics. The bacillus velezensis is preserved in the Guangdong Microbial Culture Collection Center, and the preservation number of the bacillus velezensis is GDMCC No: 66277. The bacillus velezensis is named as bacillus velezensis. The invention also provides a bacillus velezensis preparation or a bacillus velezensis liquid containing the strain. The invention also provides an application of the bacillus velezensis or the microbial inoculum thereof or the bacterial liquid thereof in degradation of kanamycin antibiotics. The application comprises the following steps: degrading the residual kanamycin antibiotics in soil or sewage, or repairing the soil polluted by the residual kanamycin antibiotics.

The invention designs a preparation method of a magnetic molecular imprinting-aptamer sandwich fluorescence sensor for detecting kanamycin. And the magnetic molecular imprinting composite material Fe3O4 (at) UiO-66 (at) MIP with a specific adsorption target object KANA is prepared. When a detection target object KANA exists, the Fe3O4-coated UiO-66-coated MIP can rapidly and specifically capture the KANA in a short time. Then, a DNA single-stranded aptamer marked with FAM is added, after the aptamer and KANA captured on the surface of the Fe3O4 at-UiO-66 at-MIP are subjected to specific recognition and magnetic separation again, an aptamer probe can enter sediment along with the magnetic composite material Fe3O4 at-UiO-66 at-MIP, the fluorescence intensity of supernate is reduced, and quantitative analysis is conducted according to the fluorescence difference value delta F. When the KANA does not exist, the aptamer cannot enter the precipitate, so that the fluorescence signal intensity is not changed. Double recognition is formed through specific binding of an MIP imprinting cavity and the aptamer, matrix interference is reduced by means of fluorescence characteristics and magnetic separation capacity, the method has the advantages of being high in adsorption capacity, specific in recognition, high in sensitivity, wide in detection range, good in selectivity and the like, and rapid and accurate detection of KANA in a complex sample can be achieved.

This invention discloses a method for directed evolution of antibiotic-resistant Escherichia coli strains based on cytidine deaminase, belonging to the field of microbial directed evolution and genetic engineering technology. This method uses E. coli as the host, introducing a recombinant plasmid expressing an optimized double-stranded cytidine deaminase mutant. Utilizing the low toxicity and high mutagenicity of this mutant, continuous passage evolution is carried out under gradient concentrations of aminoglycoside antibiotics (kanamycin and streptomycin). Combined with whole-genome sequencing, molecular docking, and reverse genetics verification, the A145T missense mutation in the wcaE gene is identified as the core functional site. This invention overcomes the shortcomings of traditional spontaneous and chemical mutagenesis, which suffer from low efficiency and significant strain damage. The mutation type is controllable, the evolutionary cycle is short, and the obtained engineered strains can tolerate up to 300 mg / L kanamycin while exhibiting streptomycin cross-resistance, and the genetic stability of the tolerance trait is strong. This method is simple, highly reproducible, and suitable for industrial breeding of stress-resistant E. coli, and can be widely applied in antibiotic fermentation, industrial microbial culture, and other scenarios.

This invention provides a composite aerogel based on Eucommia ulmoides gum and MXene nanosheets, its preparation method, and its application. The aerogel is prepared by reacting a toluene solution of Eucommia ulmoides gum with Ti3C2T... x MXene aqueous solution was mixed and a water-in-oil microemulsion was formed using a combination of ultrasound-assisted shaking. This allowed MXene nanosheets to self-assemble at the microemulsion droplet interface. Following vertical freezing and freeze-drying processes, a three-dimensional network structure of Eucommia ulmoides gum-Ti3C2T was successfully constructed. x MXene composite aerogel. The preparation method of this invention is mild and requires no chemical cross-linking agents. The resulting composite aerogel exhibits excellent adsorption performance for enrofloxacin, malachite green, Congo red, rhodamine, and kanamycin in water, with adsorption equilibrium times all within 10 minutes, enabling rapid removal of organic pollutants from water. This invention provides a new approach for the high-value utilization of Eucommia ulmoides gum and has promising application prospects in the field of water environment remediation.

The invention discloses an electrochemical aptamer sensor for detecting kanamycin as well as a preparation method and application of the electrochemical aptamer sensor, and belongs to the technical field of electrochemical biosensing analysis. According to the invention, a gold electrode assembled with a kanamycin aptamer with sulfydryl is taken as a sensing interface, a target molecule kanamycin is combined to the sensing interface, and a silver nanoparticle-zirconium-based metal organic framework material signal probe is combined with kanamycin on the sensing interface, so that the sandwich type kanamycin electrochemical aptamer sensor is constructed. The kanamycin electrochemical aptamer sensor prepared by the invention has relatively high sensitivity, relatively low detection limit and relatively wide detection range, the detection limit of the sensor is 0.085 aM, and the detection range is 0.1 aM <-1 > nM. The electrochemical aptamer sensor prepared by the invention is used for quantitative detection of kanamycin, and has the advantages of good stability, strong specificity, good reproducibility and the like.

The present application relates to the technical field of biology, and discloses a construction method of a Pseudomonas putida suicide vector and application thereof.The construction method of the Pseudomonas putida suicide vector provided by the present application takes a pK18mobsacB vector as a template to obtain a vector skeleton by amplification, and then takes Pseudomonas putida KT2440 bacterial liquid as a template to obtain a strong promoter Prib, upper and lower homologous arms of a gene x to be knocked out, and connects the upper and lower homologous arms to the vector skeleton to obtain the Pseudomonas putida suicide vector.The strong promoter Prib can increase the expression amount of sacB sucrose in the Pseudomonas putida, and enhance the sucrose lethal effect.The Pseudomonas putida suicide vector obtained can be introduced into the Pseudomonas putida, and then the strain with the target gene to be knocked out deleted can be obtained efficiently and accurately through kanamycin positive screening and sucrose negative screening.

The application discloses a pesticide composition containing zhongshengmycin and kanamycin and application thereof, and belongs to the technical field of pesticides. Effective components of the pesticide composition are zhongshengmycin and kanamycin. The mass ratio of the kanamycin to the zhongshengmycin is 1:1-9. The two effective components of the application have different action sites for killing pathogenic bacteria, and can effectively alleviate the generation of drug resistance of the pathogenic bacteria. After the zhongshengmycin and the kanamycin are compounded, synergistic effect is obvious, the control effect of the pesticide on bacterial diseases, such as citrus canker, is improved, the pesticide dosage can be reduced, and agricultural residues are reduced. Meanwhile, the prepared soluble granules do not use any organic solvent, are safe to crops, and have no residues and pollution to the environment.

The application provides a nucleic acid sequence and a method for detecting biomolecules based on a self-driven hybrid chain reaction (SHCR), which comprises a priming chain AI, a blocking chain B, a hairpin probe H1, a hairpin probe H2, a hairpin probe H3 and a hairpin probe H4, the priming chain AI comprises an aptamer sequence of a to-be-detected biomolecule and a starting sequence I, the sequence of the starting sequence I is a*‑b*, wherein a* and b* are gene fragments; the 5' end of the hairpin probe H1 is connected with b*, and the 3' end of the hairpin probe H3 is connected with a*. The application further provides a kit for detecting biomolecules based on the SHCR and a method for detecting biomolecules, in particular, a method for detecting a kanamycin residual amount in food. Through ingenious design, when the to-be-detected biomolecule exists, the sequence combination of the above biomolecule can initiate the self-driven hybrid chain reaction, the priming chain can be autonomously supplemented, the self-driven reaction process is reversely activated, thereby a more significant FRET signal is generated, and the detection sensitivity is improved.

The invention relates to a kanamycin fluorescence-electrochemical dual-mode biosensor based on a three-dimensional DNAzyme walker and application of the kanamycin fluorescence-electrochemical dual-mode biosensor, and belongs to the technical field of biosensing. The biosensor comprises a gold electrode AuE modified with a capture chain CP, a three-dimensional DNAzyme walker and a target recognition probe Apt / R of kanamycin, the three-dimensional DNAzyme walker comprises a G-quadruplex substrate chain embedded with MB, a DNAzyme chain with a self-protected annular structural domain and gold nanoparticles (AuNPs); the target recognition probe Apt / R is obtained by hybridizing an aptamer chain Apt and an aptamer complementary chain R. By adopting a fluorescence-electrochemical dual-mode detection method, the problem that single signal output is easily interfered by a false positive signal and a background signal is effectively solved, and the accuracy of kanamycin detection is remarkably improved.

The application belongs to the technical field of microorganism detection, and particularly relates to a bifidobacterium viable count detection culture medium, a detection method and application. The application provides a culture medium for detecting bifidobacterium, wherein the culture medium comprises MRS culture medium and an antibiotic solution; the antibiotic solution comprises streptomycin, kanamycin and sodium propionate. The culture medium can ensure normal growth of bifidobacterium, has strong inhibition on lactobacillus, can effectively realize accurate detection of bifidobacterium, and avoids interference of lactobacillus.

The invention provides Kineococcus G2 and application of the Kineococcus G2 in preparation of a pigment with antioxidant activity, the Kineococcus new strain G2 is CCTCC No. M20242602, the strain is spherical, the size is 1.0 * 1.5 mu m, the optimal growth temperature is 30-37 DEG C, the pH value is 7.0-9.0, and the salt concentration is 1.0%-2.0%. The strain G2 is not sensitive to bacitracin, ciprofloxacin and norfloxacin, and is sensitive to novobiocin, polymyxin, gentamicin, piperacillin, ofloxacin, erythromycin, streptomycin, kanamycin, rifampicin, ampicillin, vancomycin, carbenicillin, chloramphenicol, tetracycline, penicillin, cefoperazone, oxacillin, amoxicillin and neomycin. Pigment generated by fermentation of the G2 strain has good antioxidant activity, and when the concentration is 10 micrograms / mL, the scavenging activity on DPPH is 25.00%, the scavenging activity on hydroxyl radicals is 80.58%, and the iron ion reducing capacity is 1.57, which are all higher than those of contrast beta-carotenoid. The application of the new Kineococcus strain G2 can lay a foundation for the research of antioxidant drugs such as medical treatment and health care product development.

The invention discloses a two-color fluorescent aptamer sensor for detecting kanamycin and aflatoxin B1 in feed by using two-color fluorescent silver nanoclusters, and belongs to the field of food safety detection. According to the invention, different DNA templates are utilized to synthesize the double-color silver nano-cluster as a fluorescent probe, and the double-color silver nano-cluster has two different fluorescent colors of 530 nm and 630 nm. And a sequence rich in guanine is used as a capture probe, so that an amplification effect on signals of two kinds of fluorescence is achieved. When KAN or AFB1 exists, a corresponding target object is selectively combined with an aptamer fragment to form an aptamer-target object-aptamer sandwich structure, and the fluorescence intensity of the silver nano-cluster is induced to be enhanced through G-rich sequence and base pairing. The'lightening 'type double-color fluorescent aptamer sensor shows excellent detection performance, the KAN detection limit reaches 0.86 nM, the AFB1 detection limit reaches 0.71 nM, the'lightening' type double-color fluorescent aptamer sensor can be used for detecting kanamycin and aflatoxin B1 in a feed sample, and the reliability and application potential of the'lightening 'type double-color fluorescent aptamer sensor in multiple detection of antibiotics and toxins in the feed sample are highlighted.

The invention discloses a cerium metal organogel-derived nitrogen and sulfur-doped carbon nano-enzyme as well as preparation and application thereof, and the cerium metal organogel-derived nitrogen and sulfur-doped carbon nano-enzyme (Ce-N, S-C) is prepared by calcining a mixture of cerium metal organogel (Ce-MOG) and thiourea; a colorimetric aptamer sensor is constructed based on the combination of the nano enzyme and a kanamycin aptamer, a method for detecting kanamycin by a TMB colorimetric method is constructed based on the colorimetric aptamer sensor, the detection method has good specificity, stability and high selectivity to kanamycin (KAN), and compared with an existing detection method, the detection method has the advantages that the detection efficiency is high, and the detection cost is low. The method shows lower detection limit and higher sensitivity, and can be used for detecting drug residues in food.

The invention discloses a method for constructing a genetic transformation system of cymbidium kanran, which belongs to the technical field of plant genetic engineering, and comprises the following steps of: carrying out monoclonal propagation on rhizomes after germination of cymbidium kanran seeds to obtain vegetative propagules with stable characters, taking the vegetative propagules as transformation receptors, taking GFP (Green Fluorescent Protein) as marker genes, and constructing the genetic transformation system of cymbidium kanran. The method comprises the following steps: adding agrobacterium EHA105 into a YEB liquid culture medium containing 50 mg / L of kanamycin and 25 mg / L of rifampicin as a dip dyeing solution; placing the injured transformation receptor in dip dyeing for transformation, and then carrying out regeneration culture. The invention relates to a method for carrying out genetic transformation on cymbidium kanran by utilizing the innovative receptor and the screening culture medium, and the method can realize efficient and stable genetic transformation without genotype dependence and can solve the problem that the genetic transformation of cymbidium kanran varieties is difficult to carry out. According to the invention, an efficient genetic transformation and regeneration system of cymbidium kanran is established for the first time, and a foundation is laid for verification of related functional genes of cymbidium kanran and further development of biological research of cymbidium transgenic breeding and the like.

The application discloses a fermentation method for producing thiamine pyrophosphokinase and belongs to the technical field of bioengineering. The BL21 recombinant engineering bacteria containing pET28a-TPK, pET28a-ProS2-TPK or pET28a-SUMO-TPK are constructed, the seed liquid is prepared, the isopropyl-beta-D-thiogalactoside is used for inducing expression, the bacteria are collected, the cells are broken and the supernatant is collected to obtain the TPK crude enzyme liquid. In the fermentation, the LB / TB culture medium containing 50 μg / mL kanamycin or 100 μg / mL ampicillin is used. The SUMO label is introduced to guide the correct folding of the TPK, so that the soluble expression ratio of the TPK is more than 85%, the ratio is improved by 2 times compared with the common system, the inclusion body ratio is greatly reduced, the process is stable and has good repeatability, and an effective scheme is provided for the industrialized large-scale preparation of the TPK.

This invention relates to the field of genetic engineering technology, specifically disclosing a polyclonal antibody against citrus HIPP7 protein, its preparation method, and its applications. The method includes selecting amino acid 1-246 of the HIPP7 protein sequence for prokaryotic expression, synthesizing the sequence and ligating it into the vector pET41a to construct pET41a-HIPP7, transforming it into *E. coli*, culturing it in LB liquid medium containing kanamycin, inducing expression with IPTG, isolating and purifying the protein, and preparing a polyclonal antibody against citrus HIPP7 protein by immunizing rabbits with the HIPP7 protein. The polyclonal antibody against citrus HIPP7 protein obtained by this invention can specifically detect citrus HIPP7 protein and can be used to detect the accumulation of HIPP7 protein in different citrus tissues and under different treatment conditions, as well as to detect the accumulation of HIPP7 protein in transgenic plants.

The invention discloses a stable genetic transformation method of floating moss. The genetic transformation method comprises the following steps: (1) crushing thallus tissues of the floating moss, (2) pre-culturing explants, (3) infecting and co-culturing, (4) screening and culturing for the first time, (5) screening and culturing for the second time, (6) enlarging and culturing, and (7) verifying transformation. According to the genetic transformation method, a thallus of floating moss is taken as a starting explant, an agrobacterium-mediated hygromycin and kanamycin screening transformation system of the floating moss is established for the first time, the blank of a floating moss genetic transformation system is filled, and experimental results show that after multi-generation culture, a transformed plant can still stably express a target gene. The method has the advantages of high transformation efficiency and simplicity in operation, and can be used for subsequent genetic transformation research of unknown floating moss genes. The method has a wide application prospect.

The invention discloses an SlFMO1 gene and application thereof in regulation and control of growth and development of tomato plants, and belongs to the technical field of gene engineering. According to the method, a CRISPR / Cas9 gene editing technology is utilized, firstly, a CRISPR / Cas9-gRNA vector is constructed to accurately edit an SlFMO1 gene in tomatoes, GV3101 agrobacterium tumefaciens is utilized to conduct mediated transformation on the tomatoes, and kanamycin serves as a resistance marker to conduct screening to obtain SlFMO1-deleted mutant tomatoes. Phenotype observation and analysis show that after the SlFMO1 gene is knocked out, the plant height and the plant width of a tomato plant are obviously increased, the apical development is enhanced, the stem diameter of the plant is increased, and the inflorescence spacing is increased, which indicates that the SlFMO1 gene negatively regulates the growth and development of the tomato, and meanwhile, the expression of related genes synthesized by auxin, gibberellin and brassinolide is obviously enhanced. The discovery has important theoretical significance and practical application value for follow-up cultivation of ideal tomato varieties.

The invention discloses a microfluidic paper chip biosensor based on an aptamer nano-enzyme catalytic colorimetric strategy and application thereof, the microfluidic paper chip biosensor has the remarkable advantages of high sensitivity, low cost and portability, a new thought is provided for construction of a microfluidic paper chip detection platform, and the application of the microfluidic paper chip biosensor is also provided. A kanamycin colorimetric aptamer sensor which is high in sensitivity, high in specificity, economical and portable is further obtained, and the kanamycin colorimetric aptamer sensor has a wide prospect in the aspect of rapid detection of kanamycin in aquatic products and environmental samples.

The invention relates to a construction method of an Agrobacterium rhizogenes mediated acacia melanoxylon genetic transformation system, which comprises the following steps: by taking an acacia melanoxylon SR17 sterile single plant as an explant, selecting an Agrobacterium rhizogenes strain Ar1193, infecting for 45 minutes in a heavy suspension of which the bacterial liquid concentration OD600 is equal to 0.9 and the acetosyringone concentration is 100 [mu] mol.L <-1 >, co-culturing for 3 days, and then transferring into a bacteriostatic culture medium to induce hairy roots; and taking the transgenic hairy roots obtained by induction as explants, and inoculating the explants into a WPM culture medium containing 0.05 mg.L <-1 > TDZ and 200 mg.L <-1 > casein hydrolysate to induce regeneration of adventitious buds so as to obtain complete transgenic plants. The screening concentrations of the four antibiotics, namely kanamycin, hygromycin, glyphosate and glufosinate-ammonium, are determined; a stable and efficient acacia melanoxylon genetic transformation system is established, the hairy root induction rate reaches 63.17%, the transgenic positive rate reaches 15.42%, and the adventitious bud regeneration rate reaches 52%.

The invention belongs to the technical field of biology, and particularly relates to a bifidobacterium longum subsp. Longum FMBL B241768LS, a microbial inoculum and application of the microbial inoculum in hypoglycemic products, the bifidobacterium longum subsp. Longum FMBL B241768LS is preserved in China Center for Type Culture Collection on October 14, 2024, and the preservation number is CCTCC NO: M 20242173; the inhibitory activity of the compound on dipeptidyl peptidase IV is as high as 79.17%; the compound has a relatively good inhibition effect on the activity of alpha-glucosidase and alpha-amylase; the compound shows drug resistance to ciprofloxacin, ampicillin, penicillin G, clindamycin, kanamycin and polymyxin B; a good inhibition effect is achieved on pathogenic bacteria; the strain can be used for preparing medicines, fermented foods, health-care products and food additives for reducing blood sugar and inhibiting pathogenic bacteria, and has a wide application prospect.

The utility model discloses a light and simple double-row cotton leaf coating device which comprises a supporting rod, a mounting base is fixedly arranged on the supporting rod, a medicine tank is fixedly connected to the mounting base, a feeding hopper is arranged on the medicine tank, a driving chamber and a stirring chamber are arranged in the medicine tank, and a driving gear and a plurality of driven gears connected with the driving gear in a meshed mode are arranged in the driving chamber in a rotating mode. A rotating handle is rotationally arranged on the outer side of the medicine tank, one end of the rotating handle extends into the driving chamber and is fixedly connected with the driving gear, a stirring shaft is fixedly arranged at one end of each driven gear, one end of each stirring shaft extends into the stirring chamber and is fixedly connected with a plurality of stirring rods, and the stirring shafts are rotationally connected with the driving chamber through sealing bearings; the kanamycin solution can be directly prepared in the medicine tank, meanwhile, the kanamycin solution can be rapidly stirred, the working efficiency of preparation is improved, operation such as pipeline connection is not needed, operation is easy, the labor burden of workers is relieved, and the working efficiency of cotton leaf coating is improved.

The invention discloses an SlFMO1 gene and application of the SlFMO1 gene in regulation and control of resistance of tomato fruits to gray mold, and belongs to the technical field of gene engineering. A CRISPR / Cas9 gene editing technology is utilized, firstly, a CRISPR / Cas9-gRNA vector is constructed to accurately edit the SlFMO1 gene in tomatoes, GV3101 agrobacterium tumefaciens is utilized to conduct mediated transformation on the tomatoes, kanamycin serves as a resistance marker to conduct screening to obtain SlFMO1-deleted mutant tomatoes, it is found that when the SlFMO1 gene in the tomatoes is deleted, the resistance of tomato fruits to gray mold is remarkably reduced, and when the SlFMO1 gene in the tomatoes is deleted, the resistance of the tomato fruits to gray mold is remarkably reduced. The result shows that the SlFMO1 gene positively regulates and controls the resistance of the tomato to the gray mold. The discovery provides a new target for subsequent improvement of tomato varieties and creation of materials for resisting gray mold of fruits, and has important application prospects in molecular breeding for improving disease resistance of tomato fruits.

The present invention provides a Bacillus subtilis strain selected from the group consisting of a) the strain deposited as DSM32324,b) the strain deposited as DSM32325, and c) a mutant strain of (a) or (b) which has sensitivity for ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol; and has inhibitory activity against E. coli and Clostridium perfringens. The invention further relates to Bacillus compositions comprising at least one Bacillus subtilis strain of the invention, preferably the Bacillus subtilis strain DSM32324 and / or the Bacillus subtilis strain DSM32325, as Direct Fed Microbial (DFM), premix, animal feed additive or animal feed. The invention provides a method of improving one or more animal performance parameters selected from the group consisting of i) increased weight gain (WG), ii) lower feed conversion ratio (FCR), iii) lower necrotic enteritis lesion scoring, iv) lower necrotic enteritis frequency, v) lower necrotic enteritis mortality, vi) increased European Production Efficacy Factor (EPEF), and vii) lower mortality, by feeding a strain or a composition according to the invention to an animal.

The application discloses a gene expression vector pJXNU for actinomycetes, a construction method and application thereof. The sequence of the vector is shown as SEQ ID NO. 2. The vector is based on a pSET152 plasmid, and loaded with kanamycin and thiostrepton antibiotic resistance genes, and a 533bp DNA fragment containing three gene expression element sequences and two sets of multiple cloning sites (MCS) shown as SEQ ID NO. 1. The vector has two autonomously expressed strong gene expression elements and one thiostrepton-induced expression element, can realize autonomous high-efficiency expression of two or two groups of genes and / or induced expression of one or one group of genes on one vector, and can realize multi-type functional gene research and application in an actinomycete host.

The invention relates to a label-free fluorescent aptamer biosensor of kanamycin. According to the method, a fluorescence signal generated after a known malachite green aptamer is combined with a fluorescent dye is utilized, a target small molecule kanamycin is introduced, and combination of the aptamer and MG is disturbed under a competitive equilibrium mechanism, so that the fluorescence intensity is changed, and sensitive detection of the kanamycin is realized. The constructed biosensor has good affinity and conformational plasticity, has a linear relationship with the concentration of kanamycin in a range of 0.1-20 [mu] M, has a detection limit as low as 0.40 nM, has strong specificity and good anti-interference capability, and is suitable for detecting kanamycin residues in food, environment and drugs. The invention provides a new thought for constructing a universal micromolecule sensing platform, has the advantages of being rapid in detection, high in sensitivity and simple and convenient to operate, and has a wide practical application prospect.

The invention discloses a preparation method and application of a molecularly imprinted polymer and aptamer double-recognition gold nanoparticle-laser induced graphene composite material modified electrode, and belongs to the technical field of flexible electrochemical sensors and kanamycin detection. According to the invention, a gold nanoparticle-laser-induced graphene composite material modified electrode is used as a base material, a kanamycin aptamer is fixed through a gold-sulfur bond by using gold nanoparticles on the surface of the base material, and a molecularly imprinted polymer layer is further modified; therefore, an electrochemical sensing electrode with a molecularly imprinted polymer and aptamer dual recognition interface is constructed, and the electrochemical sensing electrode is used as a high-performance sensitive element of a sensor and shows good analysis performance in actual fish meat sample kanamycin detection. The prepared modified electrode can be used for sensitively detecting KANA in a concentration range of 10.0 pmol / L-1. 0mmol / L, the detection limit is as low as 3.3 pmol / L, and the modified electrode is good in selectivity and stability.

The invention provides an SP-1 polypeptide and application of a coding gene of the SP-1 polypeptide in inhibition of tight reaction and antibiosis, and belongs to the technical field of polypeptides. The amino acid sequence of the spider-derived SP-1 polypeptide is as shown in SEQ ID NO: 1. According to the present invention, the SP-1 polypeptide can specifically inhibit Escherichia coli and pseudomonas aeruginosa tight reaction key small molecule (p) ppGpp synthase activity, strong antibacterial activity is represented, and the MIC of the SP-1 polypeptide on Escherichia coli and pseudomonas aeruginosa is 2.4 [mu] M and 1.5 [mu] M respectively, and is significantly lower than the MIC (14.5 [mu] M and 12.3 [mu] M) of kanamycin of a positive control group under the same experiment condition; in addition, the SP-I peptide shows efficient bactericidal activity, the minimum bactericidal concentration of the SP-I peptide to escherichia coli and pseudomonas aeruginosa is 2.0 mu M, and the SP-I peptide can effectively inhibit generation of escherichia coli and pseudomonas aeruginosa biological membranes. Therefore, the SP-1 polypeptide can be used as an active ingredient to be applied to preparation of antibacterial drugs for inhibiting multidrug resistance bacteria.

The present invention discloses a method for preparing a molecularly imprinted paper-based microfluidic chip based on a metal-organic framework, which comprises the following steps: constructing a zeolite imidazole framework (ZIF-8) on a filter paper surface by a seed polymerization method and a secondary growth method; performing silanization and amination modification on the paper base in step S1; performing silicon coating and amination treatment on the paper base material in step S1; surface imprinting construction; and assembling a paper-based microfluidic colorimetric sensor. The present invention uses the above-mentioned preparation method as an enrichment and color development platform to establish a rapid colorimetric detection test strip that can be used for kanamycin in milk, thereby achieving rapid detection and analysis of kanamycin by integrating selective enrichment and color development, with simple operation and high sensitivity. At the same time, multiple characterization methods are used to explore its physical and chemical structure. The high porosity, high specific surface area and adjustable pore size of the metal-organic framework are used as advantages, and combined with molecular imprinting technology, not only the defects of the raw materials are overcome, but also its selectivity is further improved.