64 results about "Hybridization reaction" patented technology

The invention discloses a method for detecting 17 beta-estradiol by using a colorimetric-fluorescent dual-mode biosensor, and belongs to the technical field of chemical analysis and detection. According to the method, a colorimetric-fluorescent dual-mode biosensor for detecting 17 beta-estradiol is established based on oxidase-like activity and fluorescence quenching characteristics of manganese dioxide nanosheets and catalytic characteristics of alkaline phosphatase by taking a nucleic acid aptamer as a recognition molecule. The synthesis cost of the nucleic acid aptamer is low, the method has universality, and other target objects can be detected by changing the nucleic acid aptamer; mBs-DNA-ALP is prepared by using a biotin-streptavidin reaction and a DNA hybridization reaction, and a structure conversion process from double-stranded DNA to an aptamer / target compound is realized by using targeted induction, so that a detection signal is amplified; according to the method for detecting 17 beta-estradiol through colorimetric-fluorescence signals, dual-mode output is achieved, results are verified and supplemented mutually, and the specificity and accuracy of the method are improved.

The invention discloses a composition, a detection method and a kit for SpaceAS variable splicing space in-situ detection of nucleic acid. The composition comprises a pi-type probe, a U-type probe, an O-type probe, an S-type probe and a signal probe, and the O-type probe adopts an in-vitro cyclization strategy, so that the problem of low hybridization efficiency caused by dependence on enzymatic cyclization reaction in a traditional hybridization method is effectively solved; meanwhile, an efficient probe hybridization system, a high-sensitivity signal amplification mechanism and a multi-round iterative imaging process are combined, so that the detection sensitivity and specificity are remarkably improved. The detection method has the advantages of high efficiency, high sensitivity, high specificity, good repeatability, strong expandability and the like through the synergistic effect of five-step single-stranded DNA probe hybridization reaction and one-step DNA amplification reaction, and can be widely applied to space in-situ detection and analysis of variable splicing events.

The present invention relates to a respiratory pathogenic microorganism and drug resistance gene nucleic acid testing kit (gene chip method), comprising a kit body. The kit body comprises a PCR amplification reaction reagent, PCR amplification reaction consumables, gene chip hybridization reaction reagents, gene chip hybridization reaction consumables, and a specific gene probe. The gene chip hybridization reaction reagents include a hybridization solution and a 1000X cleaning solution; the gene chip hybridization reaction consumables include a gene chip and a coverslip; the PCR amplification reaction reagent is a PCR buffer solution; and the PCR amplification reaction consumables are PCR tubes. On the basis of gene chip technology in combination with novel multiplex PCR amplification technology, the present invention provides a novel respiratory pathogenic bacterium and drug resistance gene testing technology which has high testing throughput and sensitivity and good identification accuracy, is simple and easy to operate and low-cost, and is widely used as a conventional testing means; and testing results are used for guiding treatment plans and medications for patients suffering from respiratory diseases and even acute and severe patients.

The utility model belongs to the technical field of western blot reaction equipment, and particularly relates to a western blot hybridization reaction device which comprises a reaction device body, a containing cavity is formed in the side end of the reaction device body, a threaded rod is installed in the containing cavity, a movable block is installed at the side end of the threaded rod, and a hydraulic telescopic rod is fixedly installed at the upper end of the movable block. A placement plate is fixedly mounted at the upper end of the hydraulic telescopic rod, a placement groove of a circular structure is formed in the upper end of the placement plate, four mounting grooves are symmetrically formed in the periphery of the placement groove, and a clamping assembly is mounted in each mounting groove; each clamping assembly comprises a spring, a telescopic assembly, a clamping plate and an anti-skid gasket, one end of each spring is located in the corresponding containing groove and fixedly connected with the inner wall of the corresponding containing plate, the other end of each spring is fixedly connected with the corresponding clamping plate, the telescopic assemblies are located on the inner sides of the springs, and the two ends of each telescopic assembly are fixedly connected with the corresponding containing plate and the corresponding clamping plate correspondingly. The anti-skid gaskets are fixedly installed at the ends, away from the springs, of the clamping plates.

The invention relates to the technical field of molecular detection, in particular to a method, a system, a kit and a probe for detecting BRCA2 gene mutation. The detection method comprises the following steps: carrying out pretreatment and PCR amplification on a blood sample, carrying out a hybridization reaction with a probe to obtain a sample, detecting the sample based on an SERS technology, and collecting an SERS spectrum. Whether BRCA2 gene mutation exists or not is judged by identifying characteristic double peaks of a cy3 fluorophore at 1188 cm <-1 > and 1393 cm <-1 >, and the whole detection process can be completed within 2 hours. According to the scheme, the region, carrying the BRCA2 gene, on the DNA can be amplified through the specific primer pair, then the DNA is specifically combined through the improved oligonucleotide probe, and detection is achieved through the reporter molecule on the oligonucleotide probe; therefore, the detection method provided by the scheme has the advantages of high detection speed, high sensitivity and high detection result accuracy, and the problems of long time consumption and high cost of the traditional PCR or NGS technology are effectively solved.

The invention discloses a photoelectric analysis paper chip based on photo-Fenton signal amplification and a preparation method thereof, and belongs to the technical field of photoelectrochemical sensing. Through innovative design of a paper chip structure and a signal transduction strategy, a target-induced photo-Fenton cycle product is efficiently converted into a photoelectric signal which can be detected by a photoelectrode, so that a photo-Fenton cycle reaction is introduced into a photoelectrochemical analysis process as a novel signal amplification strategy which is efficient and simple and convenient to operate; therefore, the serious dependence of traditional ultra-sensitive photoelectrochemical analysis on complex design of biological recognition molecules such as nucleic acid and aptamers and tedious chain hybridization reaction is overcome. Therefore, while the detection sensitivity and reliability are ensured, the operation difficulty and the detection cost of the photoelectric analysis process are greatly reduced, the preparation process can be effectively simplified, the preparation cost is reduced, and the method has a wide application prospect.

The invention relates to a resin chamber device. This resin chamber device is provided with: a sealing member in which a slot-forming part penetrating in the thickness direction is formed; a transparent member disposed on a first surface side of the sealing member where one end of the slotted hole forming portion is open, the transparent member blocking the one end of the slotted hole forming portion; a substrate that is disposed on the second surface side of the sealing member where the other end of the slotted hole forming portion is open, and that blocks the other end of the slotted hole forming portion; a first frame, wherein the first frame is abutted against the transparent component; a second frame, wherein the second frame is abutted against the substrate; and a clamping member that clamps the peripheral edge portions of the first frame and the second frame.

The utility model discloses an in-situ hybridization instrument and relates to the technical field of detection equipment. The food processor comprises a machine body, a rotating plate is rotationally installed on one face of the machine body, a heating plate is fixedly installed on the inner bottom wall of the machine body through screws, and a containing plate is arranged in the machine body. According to the utility model, the heating plate is arranged on the inner bottom wall of the machine body and is used for providing a constant temperature environment so as to promote the hybridization reaction between a probe and a target sequence. The heating plate has an adjustable temperature range to adapt to different experiment requirements so as to meet the requirements of users, and through a limiting piece fixedly installed on the placing plate and a pressing plate constructed on the rotating plate, when a temporary loading piece is placed, the temporary loading piece can be effectively fixed, so that the use is convenient. The in-situ hybridization device solves the problems that when a temporary loading piece is placed in an existing in-situ hybridization device, the temporary loading piece is generally fixed through a pressing plate, the fixing mode is unstable, the loading piece can be inexpensive during hybridization, and the test result is influenced.

The present invention relates to the structure of an analysis plate applied to a high-speed polymerase chain reaction (PCR), and to a PCR analysis plate used for implementing an analysis of a real-time PCR, a real-time nested PCR and a post-PCR lateral flow hybridization reaction. The present invention is provided with: a check valve for enabling the maintaining of positive pressure when an elastic film expands into a convex form by having a solution pushed therein by the positive pressure; a lateral flow analysis module for analyzing a post-PCR follow-up PCR or lateral flow; and a shut-off valve enabling the controlling of the movement of the solution after each reaction ends.

The invention belongs to the field of inorganic functional materials, and particularly relates to a basic nickel carbonate modified material and a preparation method thereof.The method comprises the steps that nickel nitrate hexahydrate is dissolved in deionized water, urea and cetyltrimethylammonium bromide are added, the mixture is heated and stirred mildly, and stirring is performed to obtain a basic nickel carbonate modified material; then adding a specially-made polyaminophenylboronic acid nickel complex and a cobalt-nickel phosphate ethanediamine hybrid material, performing ultrasonic dispersion to form a mixed solution, and then performing hydrothermal reaction, centrifugal washing and vacuum drying to obtain a final product. The two special modified compounds are respectively prepared through a coordination reaction regulated by ammonia water and a hybridization reaction under high-temperature and high-pressure conditions. The modified material prepared by the method has a unique microstructure and enhanced physical and chemical properties, shows excellent application prospects in the fields of electrochemical energy storage, electro-catalytic water and environmental remediation, and particularly, the comprehensive performance of the material is remarkably improved due to the high specific surface area, abundant active sites and a stable structure.

The application discloses a new method for quantitatively analyzing interface nucleic acid hybridization reaction and application thereof, and comprises the following steps: S1, constructing a DNA tetrahedron interface; S2, imaging the DNA tetrahedron interface through a total internal reflection fluorescence microscope; S3, realizing real-time monitoring of a hybridization event of the DNA tetrahedron interface by adopting double-color co-localization and analyzing a fluorescence signal; and S4, analyzing hybridization kinetics on the DNA tetrahedron interface by recording changes of the fluorescence signal with time. The application uses the DNA tetrahedron interface for single-molecule fluorescence imaging, can realize real-time monitoring of a single nucleic acid molecule hybridization event, improve detection sensitivity and specificity, accurately analyze kinetic parameters of a hybridization reaction, help realize more accurate performance evaluation of a nucleic acid sensor, has important significance for design and optimization of the nucleic acid sensor, and thus plays a greater role in the fields of clinical diagnosis, environmental monitoring and food safety.

This invention provides a rapid hybridization reaction device for gene chips based on microfluidics, comprising a microfluidic layer based on microfluidic technology, a DNA probe microarray layer corresponding to the microfluidic channels in a dotted array, a temperature control module for providing the hybridization temperature between the DNA probes and DNA in the sample, and a fixing device that fixes and seals the microfluidic layer, DNA probe microarray layer, and temperature control module from top to bottom. Each microfluidic channel is in a continuous U-shaped configuration (positive-negative-positive-U), and is equipped with a liquid flow drive module for driving the DNA solution to flow back and forth within the microfluidic channel. After sealing, all probe array points are located within an independent microfluidic channel, and a sample dispensing orifice is provided at the upper end of the fixing device for adding samples to each independent microfluidic channel. Through the synergistic effect of temperature and flow rate, this device can reduce sample consumption, increase hybridization rate, reduce hybridization time, and avoid cross-contamination.

The invention discloses a DNA tetrahedron self-adaptive catalytic hybridization circuit for circular RNA imaging and precise gene therapy and a construction method and application of the DNA tetrahedron self-adaptive catalytic hybridization circuit. The construction method comprises the steps that a reaction solution containing T1-S2, T2, T3, T4, S2 * and an annealing buffer solution is denatured and cooled to the room temperature, and a DNA tetrahedron framework is prepared; s1, S1 * and an annealing buffer solution are mixed, heated and then cooled to the room temperature, and capture double strands (S1 / S1 *) are prepared; incubating the DNA tetrahedron framework, capturing double strands, and constructing to obtain an integrated multifunctional DNA tetrahedron; the method comprises the following steps: incubating a reaction mixture containing target circRNA with different concentrations, a DNA tetrahedron, an annealing buffer solution and BSA (Bovine Serum Albumin), and carrying out circrRNA-started DNA tetrahedron entropy-driven strand displacement hybridization reaction. According to the invention, the expression of circCDYL in cancer cells can be accurately quantified, and breast cancer patients and healthy individuals can be distinguished.

The invention relates to a homogeneous chemiluminescence immunodetection method based on nucleic acid nanometer machine signal amplification. A detection solution of the chemiluminescence immunodetection method comprises a pair of immunoaffinity probes (an antibody 1-DNA1 and an antibody 2-DNA2), a double-stranded DNA probe (a closed chain / promoter chain), a DNA nano machine and a hemin dimer nucleic acid probe (hemin-DNA3 / hemin-DNA4). When the target protein exists, the target protein can be identified by the immunoaffinity probe sandwich to form an antibody 1-DNA1 / target protein / antibody 2-DNA2 compound, DNA1 and DNA2 are hybridized and subjected to a chain substitution reaction with the double-chain DNA probe based on an ortho-position effect, a promoter chain is released, a cascade hybridization reaction on a DNA nano machine is triggered, a large number of primer chains are released, and the target protein can be identified by the immunoaffinity probe sandwich to form an antibody 1-DNA1 / target protein / antibody 2-DNA2 compound. The primer chain and the hemin dimer nucleic acid probe are subjected to chain substitution reaction, and hemin monomer nucleic acid (hemin-DNA3 and hemin-DNA4 / primer chain) is generated. The hemin monomer nucleic acids have good peroxidase activity and can catalyze an L012-imidazole-hydrogen peroxide system to generate a chemiluminescence signal, so that quantitative analysis of target protein is realized. The immunodetection method is simple to operate, sensitive and high in universality, and has a good clinical application prospect.

To provide improved assemblability and operability of a chamber apparatus.SOLUTION: A chamber apparatus 1 includes: a chamber unit 2 including: a sealing member 10 having multiple well-forming sections 20 formed therein that penetrate the sealing member in the thickness direction; a glass slide 11, attached to a first surface of the sealing member 10 where one end of the well-forming section 20 is open, closing one end of the well-forming section 20; a DNA array substrate, attached to a second surface of the sealing member 10 where the other end of the well-forming section 20 is open, closing the other end of the well-forming section 20; and a chamber frame 3 that detachably sandwiches the chamber unit 2 in the direction in which the glass slide 11, sealing member 10, and DNA array substrate overlap.SELECTED DRAWING: Figure 1

The invention discloses a library construction method for non-HPV (human papillomavirus) related cervical tumor and precancerous lesion molecular subtypes thereof based on high-throughput sequencing, which comprises the following steps: ultrasonically breaking genome DNA (deoxyribonucleic acid) of a detected sample to obtain a DNA fragment, modifying the tail end, connecting a joint, and performing purification and pre-amplification reaction, namely performing hybridization reaction on a pre-amplification sequence by using a hybridization capture reagent, according to the method, a hybridization capture reagent is adopted, DNA fragments combined through non-specific capture are enriched and removed, then an amplification reaction is carried out, a library is obtained, next-generation sequencing is carried out, original data are subjected to bioinformatics analysis, variation information is obtained, and the hybridization capture reagent comprises specific primers with the sequences shown as SEQ ID NO: 1-175. According to the present invention, the integration of the non-HPV-related cervical tumor and precancerous lesion molecule detection is achieved, the detection can be completed in one experiment, and the sequencing depth is improved by specifically enriching the target region so as to improve the sensitivity of the non-HPV-related cervical tumor and precancerous lesion molecule detection.

The application provides a biochip integrated machine, which comprises a shell and a hybridization part, a reading part and a driving part arranged in the shell. The hybridization part is provided with a liquid containing assembly and a liquid suction and discharge assembly. A reactor in which a biochip is arranged is detachably arranged in the hybridization part. The liquid containing assembly is used for containing liquid. The liquid suction and discharge assembly is connected with the reactor and the liquid in the liquid containing assembly is sucked into the reactor or the liquid in the reactor is discharged by applying pressure to the reactor. The driving part transmits driving force to the reactor to drive the reactor to move between the hybridization reaction area and the reading area. The reading part is used for reading the result of the hybridized biochip in the reading area. The application can integrate the biochip hybridization and the hybridization result reading, automatically complete the biochip hybridization reaction, the result display and acquisition, and has high working efficiency, simple and convenient operation, compact structure, flexible use and long service life.

The invention belongs to the technical field of library construction, and particularly relates to a DNA targeted library construction kit and application thereof. The kit comprises a hybridization capture reagent combination, the hybridization capture reagent combination comprises a hybridization reaction solution, and the hybridization reaction solution comprises a hybridization reaction solution 1 and a hybridization reaction solution 2; the hybridization reaction solution 1 is prepared from betaine, tetramethylammonium chloride, Mg < 2 + > and Triton X-100; the hybridization reaction liquid 2 is prepared from formamide and N-methyl pyrrolidone; hybridization of the probe and the library is facilitated, the capture efficiency is superior to that of an existing hybridization reaction solution, and Panel with different sizes and different hybridization durations can be compatible; a small panel can also achieve relatively high and relatively stable capture efficiency, the hybridization time is selectable within 1-20 h, fast and slow hybridization reagents are unified, and production and simultaneous operation of multiple products are facilitated.

The invention discloses an addressable nanoliter reactor chip and application of a nucleic acid signal amplification integrated system in single cell level detection markers. The nucleic acid signal amplification integrated system comprises aptamer DNA molecules and probe DNA molecules of a hairpin structure. According to the invention, the programmable characteristic of nucleic acid molecules is utilized to construct an aptamer-probe DNA synergistic signal amplification system; through combination of molecular beacon design and endonuclease reaction, in-situ signal multiplication of EpCAM protein is realized on a single cell level. After the aptamer recognizes the target epitope, the cascade hybridization reaction of the probe DNA is triggered, so that a single antigen binding event is converted into hundreds of fluorescent signal molecules to be released, and the signal gain is remarkably improved compared with that of a traditional immunofluorescence method.

The application discloses a PKR gene knockout cell line and a construction method and application thereof. The construction method comprises the following steps: A1, designing sgRNA primers for PKR gene knockout; A2, performing single enzyme cutting treatment on LentiCRISPR v2 plasmid to obtain enzyme cutting products; A3, performing annealing hybridization reaction by using the synthesized sgRNA primers to obtain annealing hybridization products; A4, performing a ligation reaction on the enzyme cutting products and the annealing hybridization products, and transforming the obtained reaction products into competent cells to obtain a recombinant transfer plasmid; and A5, after performing lentivirus packaging on the recombinant plasmid, infecting A549 cells by using the obtained lentivirus liquid to obtain the PKR gene knockout cell line. The application successfully constructs the A549 cell line with the PKR stable knockout, the A549 cell line can inhibit the type I interferon induced by NDV, promote virus replication and induce more serious cell death, and thus can be applied to the development of NDV vaccines.

A composition for detecting hematopoietic stem cells comprises magnetic beads functionalized with CD34 antibodies, nucleic acid probes bound to CD31 antibodies, nucleic acid probes bound to CD45 antibodies, H1 chains, H2 chains, crRNA and signal nucleic acid chains. When the two probes are fixed to the surface of hematopoietic stem cells, a long chain S is formed. The long chain S acts as an activation chain to open the H1 chain, generating a T / H1 double-stranded structure, thereby exposing the terminal sequence and opening the H2 chain, generating an H1 / H2 double-stranded structure and releasing T, and then proceeding to the next round of hybridization reaction. The end of the H1 / H2 double-stranded structure contains a partial single-stranded structure, which acts as an activation chain to activate the trans-cleavage activity of the CRISPR / cas system, randomly cutting the DNA chain, thereby releasing the terminal MB. The MB molecule can be captured by the hydrophobic cavity of CB[7] to form a stable host-guest complex, generate an electrochemical signal, and realize the detection of hematopoietic stem cells.

This invention relates to an apparatus for producing small-molecule eco-organic products through biomass multi-component catalytic hydrolysis, comprising: a primary processing unit including replaceable staged crushing sub-equipment and pulping sub-equipment for adjustable and replaceable input; a secondary processing unit including a heating fermentation sub-equipment, a catalytic hydrolysis sub-equipment, and a nutrient element coupling hybridization sub-equipment connected in sequence, to obtain secondary biomass slurry from the primary biomass output from the primary processing unit through fermentation, catalytic hydrolysis, and nutrient element coupling hybridization reactions; a combined closed-loop circulation device and an intelligent control unit for controlling the particle size of the primary processing unit, coordinating the handling of various adjustable variables such as humidity, particle size, temperature, speed, pH, concentration, weight, pressure, liquid level, and time in each sub-equipment during the reaction process, and coordinating the handling of the primary and secondary processing units by the combined closed-loop circulation device.

The invention belongs to the technical field of library construction, and particularly relates to a hybridization reaction solution and application thereof. The invention provides a hybridization reaction solution, the capture efficiency of the hybridization reaction solution is superior to that of the existing hybridization reaction solution, and the hybridization reaction solution can be compatible with Panel with different sizes and different hybridization durations; a small panel can also achieve relatively high and relatively stable capture efficiency, the hybridization time is selectable within 1-20 h, fast and slow hybridization reagents are unified, and production and simultaneous operation of multiple products are facilitated.

The invention discloses a novel method for constructing encoding microspheres by three-dimensionally assembling fluorescent dye labeled DNA molecules, which is characterized in that the fluorescent dye labeled DNA molecules are used for replacing organic fluorescent dyes and nano materials, and the fluorescent dye labeled DNA molecules and complementary DNA chains pre-anchored on the surfaces of the microspheres are assembled on the surfaces of the microspheres through DNA hybridization reaction. The method comprises the following steps: preparing a single-color or multi-color microsphere array with super-large coding capacity by taking the type and loading concentration of DNA molecules marked by a fluorescent dye as coding elements; streptavidin is modified to the surface of the coding microsphere through a biotin-streptavidin bridge, and the obtained functionalized coding microsphere can be efficiently combined with a biotinylated capture probe, so that simultaneous qualitative or quantitative detection of a plurality of target analytes is realized. The coding microsphere is large in coding capacity, low in decoding cost, environmentally friendly and high in universality, and has wide application prospects in the fields of clinical diagnosis, environment monitoring and the like.

The invention discloses a fluorescent microsphere coding method for regulating and controlling FRET efficiency based on nucleic acid and application, and belongs to the technical field of DNA detection. The method comprises the following steps: combining DNA (deoxyribonucleic acid) coding probes with different lengths and two fluorescent probes marked with different fluorescent groups to the surfaces of magnetic beads through nucleic acid hybridization; the FRET efficiency of the two fluorophores is changed, so that the fluorescence intensity change on the carboxyl magnetic beads is realized; the method comprises the following steps: S1, combining a coupling probe with a microsphere: coupling a first coupling probe to the surface of a carboxylated magnetic bead through a carboxyl-amino covalent reaction; s2, hybridization reaction: taking magnetic beads obtained by coupling, adding a DNA coding probe, a first fluorescent probe and a second fluorescent probe, reacting for a period of time in a dark place, and washing to obtain coding microspheres; and S3, decoding: detecting the fluorescence intensity of FAM and Cy3 through a flow cytometry, and decoding according to the position difference of the microspheres in the two-dimensional scatter diagram. According to the invention, coding in two dimensions of wavelength and intensity can be realized.

The processing equipment comprises an in-situ hybridization reaction shell, a servo motor and a movable top plate which is arranged on the top of the in-situ hybridization reaction shell, two movable screen grooves are formed in the in-situ hybridization reaction shell, and the servo motor is arranged on the top of the in-situ hybridization reaction shell. The screen groove is driven by the servo motor to move left and right and is used for screening powder, and a movable concave plate is arranged in the in-situ hybridization reaction shell. A servo motor drives the left side and the right side of a concave plate, so that the concave plate can drive a screen groove to move left and right, powder is conveniently screened, large-particle raw materials are prevented from affecting the mixing effect, meanwhile, the screen groove can move left and right, the screening effect is improved, the servo motor drives a stirring motor to move left and right, and the mixing effect is improved. The stirring motor can drive the stirring rod to rotate and move left and right, so that the material mixing effect is improved, and the in-situ hybridization effect is further improved.

The invention belongs to the technical field of molecular biology, and discloses a preparation method of a fluorescence in situ hybridization kit based on a hybridization chain reaction (HCR), the core components of the kit comprise a hybridization probe, an amplification probe, a washing liquid, a confining liquid, protease K, HRP-mouse anti-digoxin, and a TSA developing liquid 520 nm. According to the FISH detection system combined with the HCR signal amplification technology, when a hybridization probe and an amplification probe are simultaneously combined to a position adjacent to a target sequence, a small section of sequence at the top end can trigger a branched HCR reaction to form a macromolecular nucleic acid aggregate. Signal amplification of HCR is achieved through cascade hybridization reaction, detection sensitivity and specificity can be remarkably improved, and meanwhile the problem of background noise caused by a traditional enzymatic method is avoided. The kit disclosed by the invention is wide in sample application range, and can be used for positioning analysis of target RNA of samples such as paraformaldehyde or formalin-fixed animal and plant tissues, paraffin or frozen sections, cells and the like, and high-sensitivity detection of the single cell level of non-coding RNA.

The present invention belongs to the field of analysis and detection, and specifically relates to a biosensor for rapid detection of microcystin-LR. The present invention provides an enzyme-free biosensor for MC-LR detection based on the principles of aptamer recognition and self-assembly of hairpin probes on magnetic beads. The amplification strategy of toehold-mediated chain displacement and cyclic hybridization reaction is connected in series, and high-sensitivity detection of MC-LR is achieved by relying on a fluorescence-sensitive platform. This method simplifies the operation and reduces the cost. The entire detection process responds quickly, and the operation process can be mastered without professional training, which is convenient for rapid promotion and use. The method reaches a detection limit of up to 53fM and has good specificity. It can only specifically detect microcystin-LR, but does not specifically recognize other substances such as microcystin-LA, microcystin-YR, and microcystin-RR.