337 results about "Hemin" patented technology

The invention relates to a method for detecting trivalent arsenic in water body through a colourimetry by using protoheme peroxidase catalytic activity, chlorhematin has horseradish peroxidase activity, under the existence of hydrogen peroxide, a chromogenic substrate 3,3', 5,5'-tetramethyl benzidine (TMB) can be catalyzed to generate an oxidation reduction reaction, the solution have variable color change by naked eyes, the addition of a nucleic acid aptamer can inhibit catalytic activity, after adding the trivalent arsenic in the solution, the catalytic activity obtains recovery, so that the color of a whole system enables substantial change, the absorbance and trivalent arsenic concentration at 442nm present a direct proportion relation, thereby the method can be used for detecting the trivalent arsenic of the water body. The detection method provided by the invention has the advantages of high sensitivity and good selectivity, the lowest detection limit is 1ppb, the operation is simple, and a large-scale apparatus is not required, and the method can be used for detecting the trivalent arsenic in drinking water.

The invention relates to a novel and multifunctional photoelectrochemical sensor which is capable of triggering the light current of a water-soluble PbX (X represents sulfur or selenium) quantum dot to be increased based on G-tetrahedron/hemin. The G-tetrahedron/hemin is formed on the surface of the PbX (X represents sulfur or selenium) quantum dot by the specific identification reaction between a target object to be measured and nucleic acid recognition molecules fixed on the surface of an electrode. The G-tetrahedron/hemin compound is taken as an electron acceptor of the quantum dot and is used for carrying out catalytic reduction on dissolved oxygen, so that the separation efficiency of the photo-induced charges of the quantum dot can be improved, and the light current of the PbX (X represents sulfur or selenium) quantum dot can be increased. According to the multifunctional photoelectrochemical sensor, multiple target objects (such as DNA, thrombin, triphosadenine, adenosine monophosphate and lead (II) ions) are unmarked by selecting nucleic acid probes with different sequences; the multifunctional photoelectrochemical sensor is simple, convenient and high in sensitivity and selectivity when being used for measurement.

The present invention discloses a 17beta-estradiol visualization detection method based on DNA nano-structure, and a 17beta-estradiol visualization detection kit based on DNA nano-structure. The working principle is that 17b-estradiol interacts with aptamer, a strand displacement reaction is started, three groups of stem-loop DNA probes are constantly opened to form DNA nano-structures, a G tetramer having catalysis activity is formed on the terminals of the three DNA arms in the DNA nano-structures, the G tetramer is bound with hemin so as to form a compound having catalysis activity and similar to HRP, TMB is subjected to catalytic oxidation, and a blue substrate is produced, wherein the result is visible, and the concentration of 17b-estradiol is directly related to the blue shade. According to the present invention, the operation is simple, the whole reaction can be completed at the room temperature, the high sensitivity is provided, the detection limit on 17b-estradiol is 100 fM, the good specificity is provided, the detection result is directly visible without any detection equipment, and the method and the kit can be used for the on-site rapid detection of 17b-estradiol.

The present invention relates to an electrochemical biosensor for detecting hydrogen peroxide, a preparation method and an application thereof. The preparation method comprises the steps of (1) synthesizing the silica-three-dimensional graphene composite material; (2) doping nitrogen and carbon into the synthesized silica-three-dimensional graphene composite material; (3) pretreating a glassy carbon electrode; (4) preparing the glassy carbon electrode modified by the nitrogen-carbon-doped silica-three-dimensional graphene composite material through the dispensing method; (5) putting the glassy carbon electrode into a chloroauric acid solution to prepare gold nanoparticle-nitrogen-carbon-doped silica-three-dimensional graphene glassy carbon electrode through chronoamperometry; (6) dipping the glassy carbon electrode into a double-sulfhydryl-modified GDNA solution and cultivating for 2-4 hours; (7) dipping the composite electrode into a hemin solution for 10-14 hours. The electrochemical biosensor is good in stability and reproducibility, high in specificity and sensitivity, fast and simple and convenient to operate. The electrochemical biosensor can be used for detecting the content of hydrogen peroxide in biological samples, cosmetics and the like.

The invention relates to a miRNA (Micro Ribonucleic Acid) detection probe and a method for visually detecting miRNA. The miRNA detection probe comprises three parts: a G-quadruplex forming sequence close to a 3' end, a miRNA complementary sequence of a target to be measured in the middle, and an interference sequence at a 5' end. The probe has a hairpin structure under general conditions. After the target is added, the quantity of base pairs and stability of a DNA-RNA (Deoxyribonucleic Acid-Ribonucleic Acid) heterozygote are higher than that of a DNA double chain formed by the interference interface, and a hairpin structure is opened. The opened hairpin structure can release the G-quadruplex forming sequence under the action of a double-chain specific incision enzyme, G-quadruplex is formed under the action of sodium and potassium ions, and a catalyst with peroxidase activity is produced by assembling with Hemin. The method for detecting miRNA disclosed by the invention only requires one probe, a generated signal is visual, and expensive instruments are not required.

The invention relates to an application of inductively coupled plasma mass spectrometry in drug testing of hemin. A method for measuring concentration of stable isotope iron in animal plasma is carried out by an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method and comprises the following steps of: providing an inductively coupled plasma source mass spectrometer; determining operating conditions of the ICP-MS; providing stable isotope iron powder, marked hemin, internal standard elements and the like; preparing standard solution and internal standard solution; preparing ICP-MS diluent; establishing a standard curve; measuring the stable isotope iron concentration in the plasma; and adding the ICP-MS diluent into a sample tube containing animal plasma sample containing iron, mixing uniformly and putting the sample tube into a refrigerator to be refrigerated, and determining the concentration of the iron in the plasma by the obtained standard curve. The application of the inductively coupled plasma mass spectrometry in the drug testing of the hemin has well performances, e.g., the method has well quantification lower limit, accuracy, absolute recovery test, sample stability, medium effect and quality control requirement, and can be taken as a content measurement method for analyzing the content of the stable isotope iron in a biological sample such as the plasma.

The invention discloses a molecule detection method and a detection kit based on DNA self-assembly and G tetramers. Molecules and an aptamer interact to start a DNA self-assembly mediated strand displacement reaction, stem-loop structured DNAs are opened continuously and a closed G tetramer sequence are activated, thus generating a large quantity of G tetramer structures with activity. After being combined with hemin, the G tetramers have HRP catalytic activity and can be used for catalytically oxidizing TMB to generate a blue substrate so that the result can be seen with naked eyes. The molecule concentration is directly related to the depth of blue color. The molecule detection method is simple to operate; the whole reaction can be completed at room temperature without use of a tool enzyme; the sensitivity is relatively high, the detection limit for bisphenol A is 1pg/mL; the reaction has very good specificity; the detection result can be seen with naked eyes; no detection instrument is needed; the molecule detection method and the detection kit can be used for quick field analysis on molecules, especially on bisphenol A.

Belonging to the technical field of metal ion detection, the invention discloses a visual sensor based on functional nucleic acid of cadmium and application thereof. The sensor consists of a molecularrecognition component, a signal amplification component and a signal conversion component. The molecular recognition component is composed of cadmium ion deoxyribozyme, which comprises a substrate chain and an enzyme chain. The signal amplification component includes an isothermal amplification system and hemin, and the isothermal amplification system includes an amplification template. The signal conversion component includes a color developing agent. The visual sensor is constructed based on cadmium ion deoxyribozyme, isothermal index amplification reaction and G-quadruplex liquid phase sensing technology, has the advantages of simplicity and rapidity, high sensitivity, high specificity, high salt resistance, low cost and the like, and can be used for field detection of cadmium ions inthe environment.

Disclosed are: a prognosis diagnosis method which can diagnose the prognosis of a patient suffering from sepsis or sepsis-related multiple organ failure in a simple manner and with high accuracy and a prognosis diagnosis kit for use in the prognosis diagnosis method. The prognosis diagnosis method comprises: a first detection step of detecting a liver fatty acid-binding protein contained in urine collected from a subject with a specific antibody; a second detection step of treating the urine with a Redox reagent such as hemin and detecting a liver fatty acid-binding protein contained in the treated urine with the specific antibody; and a comparison step of comparing a detection value obtained in the first step with a detection value obtained in the second step. It is determined that the larger the detection value obtained in the second step compared to that in the first step, the worse the prognosis.

The invention provides application and a preparation method of a protein mimic enzyme based on heme and gold nanoclusters.The method includes: using carbamide for denaturation of bovine serum albumin, using 1,4-dithiothreitol for recovering the bovine serum albumin to obtain sulfydryl-containing chain bovine serum albumin, crosslinking with hemin to obtain sulfydryl-containing chain bovine serum albumin and hemin scaffold composite, and taking the composite as a stabilizer and a reducing agent to synthesize the gold nanoclusters to further obtain the protein mimic enzyme based on the heme and the gold nanoclusters.The protein mimic enzyme prepared according to the method has the advantages of low cost, high catalytic activity, high stability and the like.The defects of low catalytic activity, insolubility in water, proneness to clustering in water solutions, proneness to structural damages in oxidation media and the like of the heme are overcome, and application range of the heme is widened.In addition, the protein mimic enzyme is application to quick and high-sensitivity detection of H2O2 content in common foods, avoids complex photoelectric instruments in a detection process and is simple and easy in operation, thereby being expected to be widely applied to the field of biocatalysis.

The invention relates to a preparation method and application of an electrochemical sensor for achondroplasia prenatal diagnosis gene-fibroblast growth factor receptor 3 (FGFR3) gene polymorphism detection, belonging to the technical field of electrochemical detection. The preparation method is characterized by comprising the following steps: synthesizing a Hemin-MOFs composite material, reducing platinum nanoparticles onto the Hemin-MOFs composite material, and mixing a single-strand DNA signal probe with the composite material to obtain a biological signal probe; and carrying out layer-by-layer self-assembly by using reducible graphene oxide tetraethylenepentamine, nano gold and avidin to fix the biotinylated DNA capture probe, thereby preparing the electrochemical sensor for FGFR3-1138G>A gene polymorphism detection. The sensor is successfully used for detecting FGFR3-gene single base mutation. The sensor has the advantages of high sensitivity and high specificity, and is quick and convenient for detection. The invention provides a new detection method for prenatal noninvasive diagnosis of achondroplasia.

The invention belongs to the technical field of analytical chemistry and optical DNA biosensing and relates to a method for detecting Hg<2+> with a signal-off chemiluminescence method. The method comprises the following steps: a mispairing hairpin DNA sequence containing a G-DNA structure fragment and part of T-T is adopted; when K<+> and hemin exist, the hairpin DNA configuration is changed to form a quadruplex G-DNA structure with peroxidase catalytic activity, and the structure can catalyze hydrogen peroxide oxidation luminol to generate chemiluminiscence; when Hg<2+> exists in a system, as the hairpin DNA structure is stabilized through the formation of a T-Hg-T structure, the quadruplex G-DNA structure cannot be formed, and chemiluminiscence is quenched; according to the influence of the change of concentrationof Hg<2+> on the quenching degree of chemiluminiscence, the detection on Hg<2+> is realized. The optical DNA biosensing method has the advantages of easiness in operation, short response time, good stability, high flexibility and high selectivity.

The invention discloses an electrochemical sensor for detecting telomerase activity and a method for manufacturing the electrochemical sensor. The method for manufacturing the electrochemical sensor mainly includes procedures of sequentially adsorbing DNA (deoxyribonucleic acid) strands S1 of thionine, Au@SiO<2> and G-rich structures in the surfaces of molybdenum disulfide nano-sheets and adding Hemin into the molybdenum disulfide nano-sheets to form MoS<2>-Thi-Au@Si<O>2/DNAzyme nano-composite materials; modifying TS (telomerase substrate) precursors on the surfaces of gold electrodes, extending the DNA strands by the aid of telomerase to form DAN strands S2, screwing the DNA strands S2 and the DNA strands S1 complementarily, and ultimately detecting the intensity of electrochemical signals of catalytic hydrogen peroxide oxidation ABTS to directly detect the telomerase activity. The electrochemical sensor and the method have the advantages that the electrochemical sensor manufactured by the aid of the method is simple in operation and high in sensitivity and stability and has an important significance on detecting cancerous cells.

The invention discloses a molecular detecting method based on an exonuclease and a G tetramer and a detecting kit. Molecules are interacted with a nucleic acid aptamer, chain replacement reaction is started, a stem-loop structural DNA is opened, and then, an exonuclease mediated signal amplification technology is combined, so that a great number of G tetramer structures with activity can be generated. G tetramers are combined with hemin so as to have the catalytic activity of HRP and be capable of catalytically oxidizing TMB to generate blue substrates, a result can be seen by naked eyes, and the concentrations of molecules are directly related to the depth of blue. The molecular detecting method is simple in operation, capable of finishing the whole reaction at the room temperature, relatively high in sensitivity and favorable in specificity and can be used for rapidly detecting molecules on site; the detection limit for 17b-estradiol is 1 pM; and the detected result can be directly seen with naked eyes, but no detecting instruments are used.

The invention relates to a preparation method of a multifunctional mimic enzyme composite sphere and application thereof. A one pot type in-situ synthesis method is adopted; in an alkaline condition, hemin is used as a reducing agent and a stabilizing agent; after the hemin is mixed with chloroauric acid (HAuCl4), a mineralization reaction is carried out; a gold nanocluster mimic enzyme (Hemin-Au) with high catalytic activity is formed; afterwards, the gold nanocluster mimic enzyme, spherical graphene (SG) and ferroferric oxide (Fe3O4) are mixed and react; subsequently, sodium alginate (SA) and a calcium ion are added to carry out embedment treatment, so as to obtain the multifunctional mimic enzyme composite sphere (SA-Hemin-Au-SG-Fe3O4). The preparation method does to relate to the use of a complicated photoelectric instrument, and has advantages of being high in the catalytic activity, simple to operate, quick in response and low in cost, and the like. The mimic enzyme composite sphere is favorable in effect when being used for the catalysis, the adsorption and the degradation of some environmental organic poisons, such as phenol (Ph), methylene blue (MB), rhodamine B (RB) and the like.

The invention relates to a hemin hybrid nanoflower and a preparation method and application thereof and belongs to the field of rapid detection of food-borne pathogenic bacteria. The problems of highcost and complex design in a conventional detection food-borne pathogenic bacteria sensor are solved. The method for preparing the hemin hybrid nanoflower includes the steps of taking a 1.5 mL centrifuge tube, sequentially adding and suspending 0.03 mg of hemin and 0.06 mg of ConA in 800 [mu]L of 10 mM phosphate buffer solution (PBS), wherein the PBS contains 20 [mu]L of 120 mM CuSO4; after uniform shaking and mixing and normal temperature standing and incubation for 18-24 h, performing centrifugation at 10000 rpm for 3 to 5 minutes, discarding supernatant, adding 100 [mu]L of 0.1 mM PBS for suspension, and storing the product at 4 DEG C for use. The hemin hybrid nanoflower is simple to operate, low in cost, high in sensitivity and good in specificity.

The present invention provides a detection method and an application of HBV based on CRISPR-Cas12a and G-quadruplex hemin. Processes are as follows: DNA extracted from serum of HBV patients is used asa template, a RPA reaction system comprising an amplification primer pair, rehydration buffer and ddH2O is added to lyophozyme powder, then MgAc is added, the materials are mixed evenly and the mixture is incubated to obtain a RPA product; PS2.M DNA is dissolved in a Tris-HCL solution and a Hemin solution is added to the solution to obtain a PS2.M/Hemin solution; FnCas12a and HBV crRNA are addedto a Tris-HCl buffer and incubated to prepare a Cas12a/crRNA complex solution; and the RPA product, PS2.M/Hemin solution and Cas12a/crRNA complex solution are incubated, and ABTS and H2O2 are added for treatment, and absorbance is measured. The detection method is fast, low in cost, high in accuracy, high in sensitivity and simple in equipment.

The invention relates to a method for detecting telomerase activity with a colorimetric method based on strand displacement reaction. According to the method, in the presence of active telomerase, hybridization is performed on a prolonging product of a substrate with assistant DNA so as to release a plurality of triggering DNAs, the triggering DNAs can trigger hairpin DNA probes H1 and H2 to have self-assembled strand displacement reaction, then G-4 chains are respectively formed at two tail ends of H1:H2, hemin reacts with the G-4 chains, thus G-4 chain DNA enzyme with catalytic activity can be formed, a TMB-H2O2 system is catalyzed to have reaction, the color of a solution is changed into blue from colorless, and the solution can be oxidized into yellow if acid is added; due to addition of active telomerase, the color of the solution can be changed, visible detection on telomerase activity can be achieved, meanwhile an ultraviolet absorption spectrum of the solution can be tested, and the telomerase activity can be more accurately and sensitively tested.

The invention discloses a manufacture method of a gold plated copper thermode and application of the thermode on a temperature-controllable H2O2 sensor, comprising manufacture of the gold plated copper thermode, formation of a G-quadruplex-hemin complex and a high-sensitivity detection method for hydrogen peroxide by an electrochemical sensor based on the thermode and the G-quadruplex-hemin complex. Based on the high-temperature resistance feature of G-quadruplex-hemin DNA (Deoxyribonucleic Acid) enzyme, electrochemical catalysis response of the hydrogen peroxide on the sensor increases gradually with temperature rising (0-50 degrees centigrade). The electrochemical hydrogen peroxide sensor based on the thermode and G-quadruplex-hemin DNA enzyme provided by the invention can be used in a wide temperature range, has high sensitivity and can realize rapid detection on hydrogen peroxide.

The invention discloses a highly sensitive paper-based photoelectrochemical sensor for detecting microRNA. A paper chip is prepared by means of a wax printing technology, gold nano-particles are grownin situ in a hydrophilic working area to achieve functionalization of the paper chip, a cuprous oxide/bismuth sulfide/bismuth vanadate tertiary sensitizer is modified subsequently, and microRNA is captured through a fixed hairpin DNA chain; by means of identification of specificity and digestion effect of duplex-specific nuclease, signal amplification on microRNA is achieved, and then by means ofa multibranched hybrid chain, platinum nanoparticles are embedded into a main part of the chain, branch parts form a chlorhematin/G-tetrad structure, and a DNA concatemer with catalase bological characteristics is formed; signal amplification is further achieved, thus preparation of the photoelectrochemical sensor is completed, and highly sensitive and accurate detection on microRNA is achieved.

The invention discloses a method for constructing an alkaline/surfactant/polymer compound system detecting probe, and belongs to the field of biological sensing. A detection probe capable of sensitively detecting to-be-detected molecules such as ochratoxin A is designed by using the established method. The method is characterized by amplifying a detection signal by using a nucleic acid base interworking and nucleic acid chain continuous complementary principle, and belonging to the field of biological sensing. The method comprises the following steps that firstly, after the to-be-detected molecule acts with a nucleic acid chain H1, a configuration of the nucleic acid chain H1 is changed, so that the to-be-detected molecule is in complementary pairing with a base of a nucleic acid chain H2 to ensure that a configuration of the nucleic acid chain H2 is changed, the changed nucleic acid chain H2 can be also in complementary pairing with a base of the nucleic acid chain H1, thus the purpose that a single detection molecule initiates nucleic acid chain reaction is realized. Finally, when chlorhematin exists, peroxidase enzyme simulation sequence on the nucleic acid chain H2 can catalyze hydrogen peroxide to oxidize tetramethyl benzidine, and a colored solution is produced when a hydrochloric acid solution exists. A detection curve of the solution can be obtained according to a relationship between absorbance of the solution at a certain wavelength and the concentration of the to-be-detected molecule.

The invention discloses a detection method for salmonella enteritidis and a detection kit. A salmonella enteritidis specific aptamer is taken as a molecular recognition element, a stem-loop structure nucleic acid H1 is opened under the action of salmonella enteritidis to undergo interaction with a stem-loop structure nucleic acid H2 so as to form partial double-stranded DNA, which includes endonuclease recognition sequences, H2 is incised under the action of endonuclease to release G basic group-rich nucleotide sequences. Under the action of Hemin, a G tetramer structure with similar HRP catalytic activity is formed, can achieve catalytic oxidation of chromogenic reaction to turn colourless substrate into blue. The method provided by the invention has high sensitivity, has a detection limit is 10 cfu/mL, also has good specificity, and other common bacteria have no influence on detection. The whole detection process can be completed at room temperature. The method has the advantages of simple operation, economical efficiency and cheapness, etc. The detection result can be directly observable, and no detecting instrument is sneeded. The method can detect living bacteria directly, and has no need for lysis of bacteria.

The invention discloses a multifunctional material PANI-CMC-Fe3O4 and an application of the multifunctional material PANI-CMC-Fe3O4 to treatment of printing and dyeing wastewater. A preparing method of the multifunctional material PANI-CMC-Fe3O4 includes the following steps that in a buffer system, aniline, hemin, CMC and magnetic Fe3O4 are added in proportion and evenly dispersed; under the condition that the mixture is continually stirred at the temperature of 15-45 DEG C, a certain amount of H2O2 is added into the system every 15-20 min; the mixture is continuously reacted for 0.5 h or longer, a certain amount of hydrochloric acid is added into the system, the mixture is sealed, continuously reacted and subjected to standing, the product is washed with water and ethyl alcohol, dried and ground, and then the powder-shaped product is obtained. The multifunctional material has the good adsorption performance, the good catalytic degradation performance and the good magnetic separation performance, and can be used as a good adsorbing agent, and organic matter such as dye can be catalyzed and oxidized by adding hydrogen peroxide under the wider original pH condition while adsorbing.

The invention discloses a high-sensitivity detecting probe based on an aptazyme sequence and an intermolecular splitting G-quadruplex-hemin DNAses self-assembled nanowire, a kit and a preparation method and application thereof, and is particularly suitable for detection of adenosine triphosphate (ATP). The invention combines an aptamer, Mg<2+>-dependent 10-23 ribozyme, hybridization chain type reaction and the G-quadruplex-hemin DNAses enzymatic reaction, thereby realizing stepwise amplification of a detecting signal and substantially improving the detecting sensitivity which is up to the pmol/L level and is higher than the general detecting sensitivity level nmol/L of the prior art by 3 magnitudes. An ATP aptazyme probe is excellent in working performance, has the detecting sensitivity limited to 2 pmol/L, and is extremely high in specificity. Common UTP, GTP, CTP and other interfering substances have no effect on ATP detection; requirements of medical clinical diagnosis, metabolic studies and the like for an ultrahigh-sensitivity ATP detecting method can be met; and the high-sensitivity detecting probe is extremely high in popularization potential and actual application value inthe industry.

The invention discloses a medicine combination with function of improving nutritional anemia and a preparation method thereof. The medicine combination is prepared by spirulina platensis phycocyanin, vitamin C, vitamin B2 and hemin according to certain weight percent. The medicine combination of the invention has the function of improving nutritional anemia.