29 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 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 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 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 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 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.

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.

The invention discloses a responsive hydrogel detection reagent for mediating walking of double-leg DNA walker based on entropy driving, a corresponding aptamer sequence is screened according to the surface of a virus, a corresponding DNA double-leg walker is designed according to the aptamer sequence, and the double-leg DNA walker comprises a double-leg binding region, a leg connecting region, an aptamer binding region and an EDC starting region. Then respectively designing a substrate chain, a waste chain 1, a waste chain 2 and a fuel chain of the EDC reaction species according to the sequence of the EDC starting region; the detection reagent is rapidly prepared according to the characteristics of influenza mutation, can be stably stored, is simple and convenient to operate, and has excellent detection performance for instant detection of influenza viruses.

A kind of electrochemiluminescent biosensor based on bimetallic nanozyme and DNA walker and its application belong to the field of biosensor technology. The sensor is based on nuclear pore membrane, gold nanoparticles are loaded on the inner wall of the membrane, thiolated aptamers are designed, the aptamers are fixed to the surface of gold nanoparticles through Au-S bonds, thiolated trigger DNA and Pd@Pt nanozymes containing gold sites are mixed in PBS, coupled through Au-S bonds, and then the trigger DNA-Pd@Pt complex is drop-coated on the membrane surface modified by the aptamer, hybridized with the aptamer, fixed to the inner wall of the membrane, and then Au@Ag nanoclusters are self-assembled layer by layer on the carboxyl sites of the inner wall of the membrane by electrostatic adsorption, Track DNA is fixed to the inner wall of the membrane, then Nt.BbvCI endonuclease is added, bovine serum albumin is used to block nonspecific binding sites, CDS quantum dots are fixed on the other side of the membrane, and an electrochemiluminescent biosensor of bimetallic nanozyme and DNA walker is obtained. The sensor has the advantages of high sensitivity, low detection limit, good stability, simple preparation steps, and short detection time.

The invention discloses an AuNPs-DNA three-dimensional nano device, a preparation method thereof and application of the AuNPs-DNA three-dimensional nano device in FEN1 enzyme detection.The SR DNA with the 3'end modified with FAM and the 5 'end modified with-SH serves as a signal output molecule, meanwhile, long-chain DNA walker is modified on the surfaces of gold nanoparticles to serve as a walking foot of the DNA nano device, SR can be hybridized with the DNA walker, and a lambda exonuclease (lambda-EXO) cleavage site is generated; in the presence of a DNA protection fragment (P), P and DW are hybridized to form double strands, hybridization of DW and SR is prevented, and because an enzyme recognition site of SR is protected, no fluorescence signal is emitted. According to the constructed three-dimensional DNA nano device, in the presence of FEN1, due to the fact that FEN1 cuts 5 'Flap, lambda-EXO cutting sites are generated, DW is hybridized with SR after being released, more lambda-EXO cutting sites are generated, fluorescence signals are released, and sensitive, simple and convenient detection of FEN1 can be achieved through the fluorescence signals through a fluorescence biosensor.

The invention belongs to the technical field of immunoassay and biosensing, and provides a preparation method of an electrochemical biosensor based on efficient Ce / Tb metal organic gel and a rigid ordered chain DNA track. Ce / Tb metal organic gel of a three-dimensional network structure is adopted as a luminous body, the luminous body has the advantages of being mild in synthesis condition, easy to prepare, good in film-forming property and the like, the porous structure of the luminous body is more beneficial to full contact with a co-reaction reagent, and due to the ligand-metal antenna effect and dual sensitization of directional Ce < 3 + >-Tb < 3 + > energy transfer, the internal energy transfer efficiency is improved, and the luminous body is more stable in performance. Therefore, the ECL luminous efficiency is greatly improved. Besides, an enzyme-driven DNA walker based on the chain-shaped DNA track as a guide is designed, compared with a randomly constructed DNA track, the method has the advantages that the chain spacing can be accurately controlled, dynamic obstacles are reduced through rigid ordered arrangement of binding sites, and the rolling efficiency and speed of the DNA walker are remarkably improved. According to different electrochemical luminescence signal intensities of to-be-detected substances with different concentrations, the detection of the acute B lymphocytic leukemia marker Pax-5a gene is realized.

The invention relates to an aptamer for specifically recognizing tetrodotoxin and application of the aptamer, and belongs to the technical field of detection. The cyclic divalent aptamer disclosed by the invention has good affinity and specificity and good thermal stability, is not interfered by impurities such as ion strength and protein in globefish meat and serum during tetrodotoxin detection, and has high conformational stability. Based on the annular bivalent aptamer, the invention further designs an aptamer sensor based on a 3D-DNA walker, the aptamer sensor can specifically detect low-concentration tetrodotoxin, the detection limit is 0.02 ng / mL, the detection time is 1 h, and the detection sensitivity is high. Other marine toxins such as gonyautoxin (GTX), dinophysiotoxin (DTX), sea anemone toxin II (ATX-II), anabaena toxin-a (ATX-a) and microcystin (MC-LR) cannot be detected, and the specificity is good.