49 results about "DNA walker" patented technology

The invention belongs to the field of bacterial detection, and discloses a fluorescence electrochemical detection product based on DNA Walker and asymmetric CRISPR (clustered regularly interspaced short palindromic repeats), which comprises a magnetic bead modified with a Lock chain, a magnetic bead modified with a Walker-Reporter chain, and an electrode of which the surface is modified with ssDNA-HRP. Two signal output modes of asymmetric CRISPR (clustered regularly interspaced short palindromic repeats) technology fluorescence display and electrochemical sensing technology are adopted for detection, and due to fluorescence and electrochemical dual-mode signal output, the false positive problem existing in a single mode is prevented, and rapid and sensitive detection of staphylococcus aureus is realized. The invention further discloses a construction method and application of the detection product, the detection product can be widely applied to detection of pollution of staphylococcus aureus in the environment, detection is rapid and sensitive, and detection of staphylococcus aureus is specific, accurate and reliable.

The invention discloses a biosensor based on 3D DNA Walker and UEDC and application, and relates to the technical field of biosensors, the biosensor comprises WB-LS (at) SMBs, Nb.BbvCI, a 10 * CutSmart buffer solution, an auxiliary chain A solution and ultrapure water, the sequence of the auxiliary chain A is SEQ ID NO.1 in a sequence table; according to the biosensor based on the 3D DNA Walker and the UEDC and the application of the biosensor, non-sugar substances are detected by utilizing a common glucometer through the biosensor, high-sensitivity detection can be performed on HIV-DNA, the detection range is wide, accurate detection can be performed from 5 pM to 20 nM, and the detection line is as low as 0.3 pM; and the biosensor has good base mismatch recognition capability, so that false positive or false negative results caused by base mismatch are effectively avoided, and the detection accuracy and reliability are improved.

The present invention relates to a biosensor platform based on a multi-legged DNA walker and a DNA nanowire track and a preparation method thereof. The biosensor platform comprises a multi-legged DNA walker, a DNA nanowire track, a Mg 2+ The multi-legged DNA walker is constructed of gold nanoparticles, DNAzyme walking chains, and locking chains, and the DNA nanowire track is constructed by self-assembly of track chain SUB1 and track chain SUB2. The multi-legged DNA walker can change from a "locked" state to an "unlocked" state when a specific target exists. The walker in the "unlocked" state is in the presence of Mg 2+ With the assistance of DNA nanowires, the sensor can continuously walk along the DNA nanowire track and cut the track chain to achieve sensitive detection of the target. Due to the designability of DNA, the sensor can detect other targets by changing the corresponding DNA sequence, which is a promising sensing tool.

The invention discloses a preparation and use method of a co-reactant-free anti-pollution electrochemical luminescence sensor for detecting cadmium ions in grains, which is characterized in that the oxygen evolution reaction activity of porphyrin, the anti-pollution capability and conductivity of poly (3, 4-ethyldioxythiophene)-polystyrene sulfonate chitosan hydrogel and the luminescence stability of luminol are utilized to detect the cadmium ions in the grains. According to the recognition effect of cadmium ions on aptamers and the signal amplification strategy of a DNA walker, a non-co-reactant anti-pollution electrochemical luminescence sensor for detecting the cadmium ions in the grains in an on-off mode is constructed. The sensor disclosed by the invention can be used for judging whether the detected grain contains target ions or not according to the change of the electrochemical luminescence peak value of the cadmium ions in a detection result. The method has the advantages that the sensor is low in cost, simple in detection operation, free of co-reactants and high in pollution resistance; the cadmium heavy metal can be qualitatively and quantitatively measured; the method has high sensitivity and low detection limit, and provides a thought for detection of other ions and small molecular substances.

The application discloses a three-dimensional DNA walker biosensor based on SERS as well as a preparation method and application thereof, relates to the technical field of biosensors, and is used for detecting target lncRNA. The biosensor comprises an MB\@DNA\@Au\@Ag compound, a 3D DNA walker and an aptamer. The nucleotide sequence of the ssDNA linker is shown in SEQ ID NO:1. The nucleotide sequence of the 3D DNA walker is SEQ ID NO:7 or SEQ ID NO:8 or a corresponding reverse complementary sequence. The biosensor realizes isothermal autonomous walking of the three-dimensional DNA walker and releases MGITC coded Au@Ag SERS nanolabels through TapSAKI triggered strand displacement and Nb.BbvCI enzymatic cleavage, thereby generating a'signal-on' type Raman output. The detection limit of the biosensor for the AKI early diagnosis potential biomarker TapSAKI is as low as 1.16 fM, and reliable quantification can be realized in the range of 4.30-850 fM. Compared with RT-qPCR (LOD is about 0.26 pM), the biosensor is improved by about 2.3 orders of magnitude in the detection limit of molar concentration.

The invention discloses an electrochemical luminescence biosensor based on bimetallic nano-enzyme and DNA walker and application thereof, and belongs to the technical field of biosensing. The sensor takes a nuclear track membrane as a substrate, gold nanoparticles are loaded on the inner wall of the membrane, thiolated aptamers are designed, the aptamers are fixed on the surfaces of the gold nanoparticles through Au-S bonds, thiolated trigger DNA and Pd (at) Pt nano-enzyme containing gold sites are mixed in PBS and coupled through the Au-S bonds, then the trigger DNA-Pd (at) Pt compound is dispensed on the surface of the aptamer modified membrane, and the sensor is obtained. The preparation method comprises the following steps: preparing Au (at) Ag nano-clusters, hybridizing the Au (at) Ag nano-clusters with aptamers, fixing the Au (at) Ag nano-clusters on the inner wall of a membrane, self-assembling the Au (at) Ag nano-clusters on carboxyl sites on the inner wall of the membrane layer by layer through electrostatic adsorption, fixing Track DNA on the inner wall of the membrane, adding Nt.BbvCI endonuclease, closing non-specific binding sites by using bovine serum albumin, and fixing CDS quantum dots on the other side of the membrane. The electrochemical luminescence biosensor of the bimetallic nano enzyme and the DNA walker is obtained. The sensor has the advantages of high sensitivity, low detection limit, good stability, simple preparation steps, short detection time and the like.

The invention develops a Brucella colorimetric detection method based on DNAWalker driving double signal amplification. The detection principle is as follows: target DNA triggers AP hybridization to form Y-type connection with CP, an Nt.BbvCI restriction enzyme cutting site is exposed, DNAWalker is released through restriction enzyme cutting circulation, and target circulation amplification is realized. Meanwhile, PDANS (palladium-iron-nano particles) is synthesized through Fe < 2 + > / H2O2 Fenton reaction, a pH indicator is loaded through silver nano particle modification (PDANS (at) Ag), and a signal is enhanced. An amplified product is combined with PDANS (at) Ag through a magnetic bead sandwich structure, remarkable color change is caused, and quantitative detection can be performed through a smart phone App (such as' Color Grab ') or a microwell plate reader. The method is easy and convenient to operate, high in sensitivity and suitable for on-site rapid identification of Brucella.

The invention relates to a preparation method and application of an electrochemical sensor for in-situ growth of AuPt nanoparticles based on a ZnNi bimetal organic framework. A modification material ZnNi-MOF (at) AuPtNPs is dropwise added to the surface of a pretreated electrode, then a DNA hairpin H1 is added and fixed to the modification material through a gold-sulfur bond, meanwhile, a 3D-DNA Walker effect can be started through a target Cd < 2 + >, and a large number of DNA single chains S1 are obtained. The method comprises the following steps: adding a supernatant and a DNA hairpin H2 subjected to magnetic separation to an electrode modified with a DNA hairpin H1 in a dropwise manner so as to generate a CHA cycle reaction, and then adding a DNA hairpin H3 and a DNA hairpin H4 in a dropwise manner so as to trigger a hyperbranched HCR signal amplification strategy, so that more methylene blue is connected to the electrode, and an electric signal in a system is enhanced. And quantitative analysis of cadmium ions is realized by using electric signal change corresponding to the concentration change of methylene blue on the surface of the electrode caused before and after addition of Cd < 2 + >. The prepared electrochemical sensor shows relatively high sensitivity, relatively wide detection range, good selectivity and excellent practical application capability.

The application discloses a responsive hydrogel detection reagent based on entropy-driven mediated double-leg DNA walker walking, and relates to the field of virus detection, and discloses the following technical scheme: according to the virus surface screening corresponding aptamer sequence, according to the aptamer sequence designing corresponding DNA double-leg walker, the double-leg DNA walker includes a double-leg binding area, a leg connecting area, an aptamer binding area and an EDC starting area. Subsequently, according to the sequence of the EDC starting area, the base chain of the EDC reaction species, the waste chain 1, the waste chain 2 and the fuel chain are designed respectively; the detection reagent can rapidly prepare, stably store, easily operate and detect the influenza virus instantaneously according to the influenza mutation characteristics.

This application discloses a colorimetric detection kit for hepatitis D virus based on a logic-manipulated three-dimensional DNA walker and its application. The colorimetric detection kit includes a DNA walker comprising a walking strand W, a first locking strand L1, a second locking strand L2, an orbital strand Tr, and gold nanoparticles (AuNPs). The detection method involves mixing the sample to be tested with the DNA walker and adding a Mg-containing... 2+ After incubating in buffer solution at room temperature for 1 hour, observe the color change or measure A. 620 / A 520 Quantification is performed using ratios. The detection kit and method in this application require no reverse transcription, no protease, and no temperature control equipment. The results are visible to the naked eye and the operation is simple. The dual-target "AND" logic design provides high specificity.

This invention relates to the field of biodetection technology, specifically to a non-isolated digital multiplex detection method based on a DNA walker and TdT enzyme amplification. The method first utilizes coding microspheres with capture elements coupled to their surface to specifically bind to target miRNAs or proteins in the sample; then, specific guide DNA (gDNA) corresponding to the target molecule is released through enzymatic digestion or thermal denaturation; the gDNA then... Pf Under the action of Ago endonuclease, the DNA walker on the surface of the encoded microspheres is activated, cyclically cutting the orbital strand to generate multiple DNA fragments with 3'-hydroxyl ends. Finally, TdT enzyme is used to extend fluorescently labeled nucleotides at the hydroxyl ends, achieving in-situ signal amplification, and digital quantitative analysis is performed on the fluorescence signal of the encoded microspheres. This invention achieves high-sensitivity detection of multiple targets in a single reaction without chamber isolation, with detection limits for each target molecule reaching the fM or fg / mL level, providing an effective technical means for the early screening of major diseases such as Alzheimer's.

The invention discloses an electrochemical biosensor and a preparation method thereof, comprising a nucleic acid nanoprobe, a three-electrode system and a sensor platform, wherein the three-electrode system comprises a working electrode, a reference electrode and a counter electrode, wherein the nucleic acid nanoprobe is a trimetallic nanozyme modified by a hairpin DNA S1 sequence, and the sensor platform constructed by the invention comprises a hairpin DNA H1 sequence, a hairpin DNA H2 sequence and a hairpin DNA H3 sequence which are hybridized to form a three-legged DNA walker; the electrochemical biosensor prepared by the invention not only has a detection limit of 1.6aM for an ultra-low expressed miRNA-21 sequence, a constructed fitting equation has a high fitting degree, a wide detection concentration range, and a high recognition degree for the miRNA-21 sequence, indicating that the method has higher selectivity, can effectively avoid false positives or false negatives in detection, and is conducive to accurate qualitative detection and quantitative analysis of ultra-low expressed miRNA-21 sequences in early cancer.

The application discloses a method for fluorescent analysis of APE1 enzyme based on a three-dimensional multi-legged DNA walker constructed by double gold balls. AuNPs as a basis to construct two systems, one of which is to modify the walker chain to AuNPs according to 500:1 to serve as a walker, named AuNP-W; the other is to modify the Sub chain to AuNPs according to 1000:1 to serve as a track, named AuNP-T. In addition, endogenous ATP serves as the driving force for the continuous walking of the DNA walker. 2+ buffer to anneal AuNP-W and Block chain to form double-stranded AuNP-W / B; use TAE / Mg 2+ buffer to anneal AuNP-T and ATP aptamer chain Apt (containing FAM fluorophore) to form double-stranded AuNP-S / A; mix AuNP-W / B, AuNP-S / A and ATP according to a certain proportion to obtain a biosensor for fluorescent analysis and detection of APE1 enzyme, add APE1 enzyme with different concentrations, and perform real-time fluorescent quantitative analysis under the condition of 37 DEG C to measure the fluorescence curves corresponding to APE1 enzyme with different concentrations; add the sample to be measured into the biosensor for fluorescent analysis and detection of APE1, set the same detection conditions, measure the fluorescence curves of different samples to be measured, and obtain the specific detection results of APE1 enzyme.

The invention discloses a miRNA (micro Ribonucleic Acid) detection platform based on a self-feedback double DNAwalker nano system and nano MnO2. The miRNA detection platform comprises a DNAwalker A, a DNAwalker B and a capture probe Cp. The capture probe plays a role in capturing miRNA in a solution and then activating DNAwalkerA. The cutting products of the two DNAwalkers are activators of each other, a self-feedback loop can be established between the two DNAwalkers, and the signal amplification capability is enhanced. The sea urchin-shaped nano manganese dioxide is used as a delivery carrier, so that the delivery efficiency is improved, and Mn < 2 + > can be provided in cells. By using the capture probe, the expansibility of a detection platform is enhanced, and the application range is expanded. The introduced sea urchin-shaped nano manganese dioxide can also be used as a delivery carrier, the delivery efficiency is improved, and the problem that a nucleic acid probe is difficult to enter cells is solved, so that the detection of miRNA in the cells can be realized.

The invention provides a self-assembly label-free enzyme-free electrochemical HPV16E7 detection platform as well as a preparation method and application thereof, and belongs to the technical field of biological analysis. According to the invention, a magnetic alpha-Fe2O3 / Fe3O4 (at) Au / Sub / BSA signal transmission medium, a CRISPR / Cas14a system and a double-foot DNA walker are organically combined to prepare a self-assembly label-free enzyme-free electrochemical HPV16E7 detection platform, and a more reliable and accurate means is provided for HPV16E7 detection; the linear detection range of the electrochemical HPV16E7 detection platform is 100 fg.mL <-1 >-10 [mu] g.mL <-1 >, the detection limit is 67.17 fg.mL <-1 >, and the quantification limit is 0.22 pg.mL <-1 >; the electrochemical HPV16E7 detection platform has the advantages of no need of enzyme, no need of marking, no need of pretreatment, fast and convenient detection process, low cost and good practicability.

The invention discloses a circulating miR-375 high-sensitivity electrochemical detection device and a circulating miR-375 high-sensitivity electrochemical detection method based on a three-foot DNA walker. According to the device, a large number of probes B are generated through a strand displacement amplification technology, and chain extension and specific splitting decomposition of Nb. BbvCI in the presence of target miR-375 are initiated by utilizing Klenow polymerase. After the probe B is hybridized with the Block chain, the inactive three-chain DNA walker is activated. The activated walker moves on a gold electrode interface supported by the TDN, and the Fc labeled probe is cracked to generate an electrochemical signal. And a square wave voltammetry method is adopted to detect signals, so that high-sensitivity detection of the circulating miR-375 is realized. The method has high selectivity, only miR-375 can cause obvious signal change, and other interference sequences and mismatched sequences are not obviously influenced. The method shows good performance in clinical samples, can distinguish glioma patients in different stages, and has important clinical application value.

The invention belongs to the technical field of DNA walker preparation, and particularly relates to a multi-foot DNA walker and a preparation method and application thereof. Based on a cohesive end mediated recognition mode and an RCA amplification mediated multi-legged DNA walker, multiple detection can be performed on ctDNA through the multi-legged DNA walker, three ctDNAs can be simultaneously detected in one-time analysis, the detection limit reaches the aM level, and high sensitivity is achieved; the ctDNA sequences with different single basic groups can be accurately distinguished, and the specificity is relatively high. In addition, the three ctDNAs in a clinical serum sample can be simultaneously and quantitatively detected, and the method has great application potential in the aspect of early screening of tumors.

The application belongs to the technical field of cell detection, and particularly relates to a bionic Taraxacum isothermal amplification system and application thereof. The bionic Taraxacum isothermal amplification system is composed of six-legged DNA walker, nonlinear DNA self-assembly technology and an asymmetric carrier, AuFe Janus nanoparticles, with high signal probe loading efficiency, and shows significant amplification efficiency. Compared with a traditional isothermal amplification system, the amplification efficiency of the bionic Taraxacum isothermal amplification system is increased by about 6.72 times.

The application discloses a click-type electrochemiluminescence biosensor based on a 3D DNA Walker and application of the click-type electrochemiluminescence biosensor in preparation of a detection system for detecting myocardial infarction miRNA. The 3D DNA Walker accurately starts relative motion between particles, and the application realizes signal amplification for a click reaction connector. An ECL signal of AgNCs is located at the other end of alkyne DNA constituting a click reaction, and is used for super-sensitive detection of the ECL signal. The application uses simple and low-toxicity AgNCs as an ECL emitter, avoids a labeling process of the whole experiment, and is conducive to further sensing application. The combination of click chemistry and relative motion between particles of a 3D DNA Walker ECL sensing platform fully utilizes the relative motion between particles of the 3D DNA Walker and the advantages of the click chemistry reaction, so that myocardial miRNA can be stably and accurately detected in different real samples.

The invention discloses a mycobacterium tuberculosis colorimetric detection method based on DNAWalker driving double-signal amplification. The detection principle is as follows: target DNA triggers AP hybridization to form Y-type connection with CP, an Nt.BbvCI restriction enzyme cutting site is exposed, DNAWalker is released through restriction enzyme cutting circulation, and target circulation amplification is realized. Meanwhile, PDANS (palladium-iron-nano particles) is synthesized through Fe < 2 + > / H2O2 Fenton reaction, a pH indicator is loaded through silver nano particle modification (PDANS (at) Ag), and a signal is enhanced. An amplified product is combined with PDANS (at) Ag through a magnetic bead sandwich structure, remarkable color change is caused, and quantitative detection can be performed through a smart phone App (such as' Color Grab ') or a microwell plate reader. The method is easy and convenient to operate, high in sensitivity and suitable for on-site rapid identification of mycobacterium tuberculosis.

The present invention discloses a double-nicking enzyme-driven double-free-foot DNA walker biosensor, as well as its preparation method and application. First, the DNA double foot is released through the competitive binding between the biotinylated aptamer on the functional magnetic beads and AβO and Tau. Then, the free DNA double foot walks on the electrode surface with the assistance of the double-nicking enzyme, and releases the substrates of AβO and Tau from the electrode surface, generating a one-to-many signal amplification effect. DNA walkers have been widely explored and applied as elements for preparing biosensors to detect disease-related biomarkers. The sensor of the present invention can not only simultaneously and sensitively detect AβO and Tau, but also make the diagnosis of AD more accurate in a complementary manner.

This invention discloses a methyltransferase sensor based on a DNA walker and hyperbranched rolling circle amplification, and its application, relating to the field of biosensors. The methyltransferase sensor includes a recognition probe, a DNA walker, and a hyperbranched rolling circle amplification system; the recognition probe includes H... M Identification probes and / or H D Identification probe, the H M The nucleotide sequence of the recognition probe is shown in SEQ ID NO.1, wherein the H D The nucleotide sequence of the recognition probe is shown in SEQ ID NO. 2. This invention employs a dual amplification strategy of DNA walker and HRCA to achieve highly sensitive detection of methyltransferases, reducing the blank signal in the detection. Simultaneous detection of two different methyltransferases can be achieved through simple recognition probe design. The detection experiment does not require complex temperature cycling or expensive instruments; it can be completed in a single centrifuge tube, resulting in low system cost.

The present invention provides a method for preparing a signal reversal type photoelectrochemical biosensor for detecting cancer markers, comprising the steps of preparing an indium tin oxide / titanium dioxide electrode, preparing an indium tin oxide / titanium dioxide / single-stranded auxiliary probe electrode, preparing a conjugate Ab1-Fe3O4@Au-DNA, preparing a conjugate Ab2-AuNPs-DNA, constructing an intermediate probe, and preparing a sensor. The present invention also provides a biosensor prepared using the above method and its application. The above biosensor for detecting cancer markers is based on the direct contact photocurrent direction reversal strategy, the targeted induced three-dimensional dual-support DNA walker cyclic signal amplification technology, and the adsorption characteristics of metal organic framework materials. The photocurrent signal reversal design is performed. Therefore, the above biosensor can realize environmentally friendly detection of cancer markers, and has the advantages of high sensitivity, high selectivity, good reproducibility, high stability, etc.

The invention discloses a preparation method of a spherical DNA nano machine for detecting O6-methylguanine-DNA methyltransferase (MGMT) and application of the spherical DNA nano machine in detection of the expression level of tumor cells MGMT. The method comprises the following steps: firstly, designing a DNA walker with MGMT recognition and signal amplification functions, and fixing the DNA walker on the surface of a gold nanosphere through sulfydryl modification to construct a spherical DNA nanomachine; when the MGMT interacts with a DNA Walker chain, a methylated basic group G on DNA enzyme can be repaired, so that the activity of the DNA enzyme is recovered, an enzyme digestion reaction is initiated, a Track chain marked with a fluorophore is broken and released, a fluorescence signal change is generated, and high-sensitivity detection of the MGMT is realized. The method can effectively detect the MGMT protein in a low concentration range, and has a good biomedical application prospect.

The present invention belongs to the field of biological detection technology, and relates to a biosensor based on a dynamic DNA nanosystem driven by strand displacement reaction, which is composed of a target recycling unit and a multi-legged DNA walker unit; in the target recycling unit, the closed multi-legged DNA walker can release the multi-legged DNA walker under the combined action of the fuel strand F and the target nucleic acid. In the multi-legged DNA walker unit, the closed gold electrode can release the closed strand B2 under the action of the labeled DNA and the released multi-legged DNA walker, so as to realize the ultrasensitive quantitative detection of the target nucleic acid through the detection of the electrochemical signal ratio between the first electrochemical signal material and the second electrochemical signal material. The biosensor based on the dynamic DNA nanosystem driven by strand displacement reaction provided by the present invention can ultrasensitively detect nucleic acids.

The application relates to a preparation method and application of an electrochemical sensor for sensitive detection of lead ions based on a metal nanocomposite. 2+ The introduction of the target Pb 2+ triggers the S-DNA cleavage of the DNAzyme to cut off a single-strand DNA, and simultaneously initiates the DNA Walker effect to obtain a large amount of single-strand DNA. The supernatant after magnetic separation is added dropwise on an electrode modified with HP1, after incubation, the single-strand DNA serves as an initiation chain to initiate the CHA signal amplification reaction, so that more and more signal probes are connected to the electrode surface, and the electrical signal in the system is enhanced. The quantitative analysis of lead ions is realized by using the change of the electrical signal corresponding to the change of the methylene blue concentration on the electrode surface before and after the addition of Pb 2+ The prepared electrochemical sensor has high sensitivity, a wide detection range, good selectivity and excellent practical application capability.

The invention provides construction of a rapid detection technology based on three-dimensional DNA walker operation and polymerization cutting reaction and application of the rapid detection technology in detection of kanamycin content in animal-derived food, and belongs to the technical field of sensing detection. The method comprises the following steps: preparing gold nanoparticles (AuNPs) by adopting a standard sodium citrate reduction method, then modifying thiolated orbital hairpin DNA and closed walking DNA to the surface of the AuNPs by utilizing the strong Au-S chemical bond action of sulfydryl and the gold surface so as to prepare a three-dimensional DNA walker, and further applying the rapid detection technology to the detection of the kanamycin content in animal-derived food. On one hand, the steric effect of a three-dimensional space structure of AuNPs is utilized, the anti-interference capability of the nucleic acid probe is enhanced, the probability that a nucleic acid chain on the surface is degraded by nuclease is effectively reduced, and the accuracy and credibility of the probe in practical application are improved; and on the other hand, the inherent signal amplification capability of the three-dimensional DNA walker is utilized, and the double amplification of the polymerization cutting reaction is combined, so that the detection speed and sensitivity are improved, and the rapid and sensitive detection of kanamycin in animal-derived food is realized.

This invention relates to a fluorescence detection method for Staphylococcus aureus based on a navigation-type DNA walker and a fluorescence regulation mechanism. It utilizes a dual-enzyme recognition reaction system of exonuclease I and exonuclease III to identify and distinguish samples containing / without Staphylococcus aureus. Samples containing Staphylococcus aureus generate an efficient fuel chain in the dual-enzyme recognition reaction system, causing the DNA walker to shift along its trajectory, further triggering fluorescence resonance energy transfer, ultimately obtaining an amplified fluorescence signal correlated with the target concentration. The concentration of Staphylococcus aureus in the contaminated sample is determined based on the relationship between fluorescence intensity and Staphylococcus aureus concentration. This invention improves the controllability and efficiency of the DNA walker, reducing the risk of derailment and interruption. The detection range is 9-90 CFU / mL. ‑1 Within its detection range, the accuracy of quantitative detection reaches 100%, and the reproducibility and recovery rate exceed 98%, capable of detecting substances containing 2 CFU / mL. ‑1 The sample of Staphylococcus aureus.

This invention discloses a DNA walker, a paper-based miRNA sensor, and their fabrication methods and applications. The fabrication method of the DNA walker includes: thiolation of a first probe using TCEP, followed by incubation with gold nanoparticles to obtain a first probe / gold nanoparticle complex; aging the first probe / gold nanoparticle complex in a first buffer solution, followed by reaction with MCH to obtain gold nanoparticles modified with the first probe; and incubating the first probe-modified gold nanoparticles, a second probe, and the first buffer solution, followed by dispersing the resulting precipitate in a second buffer solution to obtain the DNA walker. The paper-based miRNA sensor prepared by this invention has advantages such as ease of use, simple operation, and no need for large-scale instruments, enabling convenient miRNA detection and showing broad application prospects in the detection field.

The invention belongs to the technical field of cell detection, and particularly relates to a bionic dandelion isothermal amplification system and application thereof. The bionic dandelion isothermal amplification system is composed of a hexapod DNA walker, a nonlinear DNA self-assembly technology and asymmetric carrier-AuFe Janus nanoparticles with high signal probe loading efficiency, and the obvious amplification efficiency is shown. Compared with a traditional isothermal amplification system, the amplification efficiency of the bionic dandelion isothermal amplification system is improved by about 6.72 times.