78results about How to "Wide linear detection range" patented technology

The invention relates to an azido-containing naphthalimide compound and applications of the azido-containing naphthalimide compound in detecting hydrogen sulfide, wherein the azido-containing naphthalimide compound is constituted by a novel fluorescence molecular probe and three different detection systems. The fluorescence molecular probe makes use of reducibility of the hydrogen sulfide; the spectrum of the compound is obviously changed before and after the fluorescence molecular probe reacts with the hydrogen sulfide, and the color is changed to be yellow from nearly colorless; different surfactants are added into the solution, so that the response time can be changed and the linear detection range on the hydrogen sulfide is expanded. The technology is characterized by sensitive reaction, fast response speed and wide linear range, and is particularly suitable for detecting the content of the hydrogen sulfide in organisms.

A gas sensor is disclosed, which includes two separate metal electrodes on a surface of a substrate and a semiconductor thin film deposited on the surface of the substrate and connecting the two metal electrodes. The semiconductor thin film contains zinc oxide or a mixed oxide of zinc and indium, and the zinc oxide or the mixed oxide of zinc and indium are in the form of nanowires which constitute a gas-sensing surface of the semiconductor thin film. The nanowires have a diameter of 50-900 nm. The present invention also discloses a method for detecting the presence of a NOx gas.

The invention relates to the field of medical immunology, and especially relates to a whole blood C-reactive protein detection kit. The kit includes a reagent R1 and a reagent R2, and the reagent R2 uses a C-reactive protein antibody to respectively sensitize latex particles having different particle sizes. Results show that the kit has the advantages of wide linear detection range, high sensitivity, good accuracy and good precision. Compared with existing human whole blood CRP turbidity kits, the kit in the invention widens the linear range, and especially enhances the detection sensitivity to low-value samples. The peripheral blood or venous blood whole blood of a patient can be used as a test sample, so the blood sampling pains of patients and especially newborns and burn patients are reduced, and true whole-blood and full-range detection of clinically hypersensitive common CRP samples is achieved.

The invention provides an immunochromatographic test strip. The test strip comprises a sample pad, a binding pad, a cellulose nitrate membrane, an absorbent pad and a backing pad, the cellulose nitrate membrane comprises a detection line and a quality control line, and the cellulose nitrate membrane also comprises a double antibody line. The double antibody line is arranged between the detection line and the quality control line. The invention also provides a making method and a detection method of the immunochromatographic test strip. The immunochromatographic test strip reserves the advantages of simple operation, simple structure and low cost of traditional immunochromatographic test strips, effectively avoids the false negative phenomenon appearing in the detection of high concentration of a substance to be tested of traditional test strips, effectively improves the detection accuracy of immunochromatography, and enlarges the linear detection range; and the test strip comprehensively utilizes the signal intensities of the above lines in a display area and the relationship among the signal intensities of the three lines not limited to the signal intensity of the detection line, so the test strip can be used to accurately determine the concentration of the substance to be tested, and the sensitivity and the specificity of immunochromatographic detection are greatly improved.

The invention discloses a method for quickly and accurately determining 4 heavy metals in cigarette smoke. The method comprises the following steps of: accurately weighing a cigarette powder sample; placing the cigarette powder sample in a triangular flask with a stopper; adding 5ml of nitric acid and 5ml of 30% of hydrogen peroxide; digesting by heating in medium flame for 5 minutes, cooling for 2 minutes, heating in medium flame for 5 minutes and heating in high flame for 15 minutes; taking out after cooling, discoloring by active carbon, filtering and transferring to a sample flask for measuring; guiding a sample solution to an inductive coupling plasma emission spectrum mass spectrometer for detecting, reading out the content of heavy metals into the to-be-measured sample cut cigarette and cigarette ash; representing the content of the heavy metals in cigarette smoke of the cigarette by using a subtraction method according to the difference value between the cut cigarette and the content of the heavy metals in the cigarette ash. The method for quickly and accurately determining the 4 heavy metals in the cigarette smoke is accurate in test, simple to operate, high in flexibility and good in repeatability. Moreover, the method is suitable for the cigarette industry and carrying out quantitative measurement onto the heavy metals in the cigarette sample, so that the blank in the technical field is filled up.

The invention belongs to the technical field of dopamine and uric acid, and discloses a three-dimensional carbon fabric / nickel iron layered hydroxide coated cobaltosic oxide nano-wire composite material, as well as a preparation method and application thereof. The preparation method comprises the following steps: 1, reacting a carbon cloth in nitric acid having a concentration of 3mol / L for 2 hours to prepare a functional three-dimensional carbon cloth; 2, soaking the functional three-dimensional carbon cloth in mixture of cobalt nitrate, urea and ammonium fluoride, reacting for 6-8 hours, cooling, washing, drying, and calcining the dried product in a tube furnace in presence of nitrogen at 400 DEG C for 2 hours; and 3, reacting for 100 seconds at a working voltage of negative 1.0V by using the three-dimensional carbon cloth / cobaltosic oxide nano-wire array composite material as a work electrode, and washing with deionized water to prepare the composite material. The preparation methodis simple, can be used for quickly and efficiently detecting dopamine and uric acid, and has a wider linear detection range and lower detection limit.

The invention relates to the technical field of medical detection, in particular to a lipoprotein detection kit. The kit comprises a R1 reagent and a R2 reagent, wherein the R1 reagent is prepared from a buffer solution, BSA (Bull Serum Albumin), chylomicron dissociation agents, surfactants, sodium chloride and preservatives; the R2 reagent is prepared from a buffer solution, lipoprotein multiresistant latex microspheres, aminopropionic acid, EDTA (Ethylene Diamine Tetraacetic Acid), BSA, sugar and preservatives. The kit can effectively eliminate the interference effect of chylomicrons in samples to be tested; the accurate determination of lipoprotein in specimens with high chylomicron contents is realized; the sensitivity is high; the linear detection range is wide.

The invention discloses a preparing method and application of electrode material of glucose sensor without enzyme. The method comprises steps of making the prepared aqueous of solution cupric nitrate / PVP polyvinyl pyrrolidone form liquid-phase thin film with uniform thickness on cleaned conductive base; placing the conductive base of the liquid-phase thin film to liquid nitrogen slowly, and calcination treatment in vacuum freeze drying machine; and conducting hydrothermal reduction to get electrode material with three-dimensional open micro-nano porous structure. The electrode material has three-dimensional open macroporous structure, micropore structure and mesoporous structure. As electrode material of glucose sensor without enzyme, the material has good activity of electrocatalytic oxidation, high sensitivity, wide linear response scope, and better selectivity. The preparing technology is simple, has low influence on environment and low cost, and can be put into large scale of production.

The invention relates to a pretreatment method for detecting organochlorine and pyrethroid pesticide residues in a tea sample. The pretreatment method of organochlorine pesticides and pyrethroid pesticides in the tea sample comprises steps as follows: (1), smashing; (2), extracting; (3), purifying; (4), filtering to obtain a to-be-measured liquid sample for GC-ECD (gas chromatography-electron capture detection) analysis. The method is simple and rapid, the pretreatment time of the sample is shortened, besides, the solvent consumption is low, matrix interference is effectively reduced, and one rapid, effective and low-cost sample pretreatment technology is provided for simultaneous detection of organochlorine and pyrethroid pesticide residues in the tea.

The invention specifically relates to a fluorescence detection method for risky material fluorine in tea leaves and belongs to the technical field of food safety detection. The fluorescence detectionmethod for risky material fluorine in tea leaves provided by the invention specifically comprises the following steps: taking a methyl alcohol mixed liquor of yttrium chloride, ytterbium chloride, holmium chloride, oleic acid, 1-octadecene, ammonium fluoride and sodium hydroxide as a raw material for preparing a hexagonal up-conversion nano-crystal; adding cyclohexane, IGEPAL CO-520, tetraethyl orthosilicate and APTES, thereby acquiring an aminated hexagonal up-conversion nano-crystal; mixing with a curcumin aqueous solution, thereby acquiring a specific mixed detection system; establishing afluorine ion detection standard curve; determining the fluorine content in the to-be-detected tea leaves. According to the invention, high sensitivity and specificity detection for fluorine in tea leaves is realized in the manner of preparing a fluorescence signal enhanced substrate through nanometer controllable self-assembling and establishing a stable specific fluorine ion detection system, sothat the fluorescence detection method has wider linear detection scope and lower detection limit and is expected to be applied to large-scale detection for risky material fluorine in tea leaves.

The invention discloses a method for quantitatively detecting toxigenic microcystis and a special standard substance thereof. The standard substance for detecting the toxigenic microcystis in a sample to be detected is recombinant plasmid or recombinant bacterium or recombinant cell which contains mcyA gene; and the sequence of the mcyA gene is sequence 1 in the sequence list. The departure plasmid of the recombinant plasmid is pMD-18T.The standard substance has the characteristic of combination of broad spectrum identification and specificity, high sensitivity, simple preparation method, long retention period, good purity and wide linear detection range, thus being capable of being applied to fast quantitative detection of the toxigenic microcystis in a sample in the water environment.

The invention discloses a pressure porous valve chip and a detection method thereof and belongs to the technical field of medical instruments. The pressure porous valve chip comprises a substrate sheet and a pressure valve body; a channel sheet is tightly attached to the upper side of the substrate sheet; a plurality of microfluid branch channels communicated with upper mounting holes are distributed at the downward end of the channel sheet; liquid storage grooves are formed in the channel sheet at the ends, away from the upper mounting holes, of the microfluid branch channels; a plurality of liquid inlet holes in one-to-one correspondence with the liquid storage grooves are formed in the channel sheet;the pressure valve body is connected with the channel sheet and the substrate sheet;and a plurality of fluid through holes in one-to-one correspondence with the microfluid branch channels are formed in the height direction of the pressure valve body; the fluid through holes can cover the areas where the corresponding microfluid branch channels are located; the downward end of the channel sheet is provided with a circulation area, a first microfluid main channel communicated with the circulation area and a negative pressure connector; one end of the circulation area is communicated with the other ends of the fluid through holes; and the other end of the circulation area is communicated with the negative pressure connector through the first microfluid main channel. The pressure porous valve chip is convenient to operate and high in flexibility.

The invention relates to a rapid measurement method of soil available potassium. The method comprises the following steps: (1) extraction: weighing a certain amount of a soil sample and placing the soil sample into a container, adding phosphorus-free active carbon, adding an universal soil extractant--a NaHCO3 aqueous solution with concentration of 0.6-0.7 mol / L, oscillating for 3-5 min, and filtering; (2) turbidimetry reaction: respectively fetching a blank control solution, a standard solution and a solution to be measured, respectively adding a soil available potassium masking agent and a soil available potassium turbidity agent, and standing; and (3) nephelometry test: adjusting optical path wavelength to 420 nm, using the universal soil extractant solution as the blank control solution, respectively measuring absorbance values of a potassium standard solution and the solution to be measured at the absorbance measurement gear, or adjusting a reference scale value based on the rapidly available potassium standard solution at the concentration measurement gear, placing the solution to be measured into the optical path, and correspondingly calculating or reading the content of rapidly available potassium in the soil sample to be measured. Based on existing rapid measurement, the technology of the invention is simplified much more, costs are reduced, and stability can be raised.

The invention discloses a mercury ion probe GC / HD / AuNS / PT+MB and a preparation method thereof. The method comprises the following steps: firstly, compounding organic functional molecule phenylthiourea PT specifically recognizing and combining with mercury ions, modifying onto an electrode, and adopting a method for electrically depositing gold and nanometer gold ball amplifying signals, thereby acquiring the mercury ion probe GC / HD / AuNS / PT+MB. The invention also provides an application of the mercury ion probe GC / HD / AuNS / PT+MB in detecting mercury ions. The mercury ion probe disclosed by the invention has the advantages of high sensitivity, high accuracy, high selectivity and low detection limit, the detection for mercury ions can be realized, the purpose of effectively removing mercury ions can be achieved, and thus the application prospect is wide.

The invention discloses a PtNi nano-alloy electrochemical sensor for detecting dopamine. The PtNi nano-alloy electrochemical sensor is characterized in that 4 microliters to 5 microliters of a binary PtNi nano-crystal ethanol solution is coated on a glassy carbon electrode to form a modified electrode PtNi / GCE; meanwhile, the modified electrode PtNi / GCE, a silver / silver chloride electrode and a platinum plate electrode form a three-electrode system; the dopamine is directly detected by utilizing an electrochemical working station. The electrochemical sensor disclosed by the invention has special sensitivity and stability on the dopamine and has relatively low detection limit, relatively wide detection range and good anti-interference property.

As an important member of the miRNA family, miRNA-21 has already been widely concerned as a tumor biomarker for breast cancer. As the sequence of the miRNA-21 is short, the expression level of the miRNA-21 in cells is low, and the similarity between the miRNA-21 and the sequence of other family members is high, certain difficulty and challenge still exist in high-sensitivity detection of the miRNA-21 clinically. The invention provides a novel ratio-type fluorescent probe based on a metal organic framework loaded with gold nanoclusters, a metal organic framework material with large specific surface area and high porosity is used as a carrier, the gold nanoclusters are generated through an in-situ synthesis method, and the designed and synthesized double-chain probe is assembled on the surface of the carrier. When the probe constructed by the invention is used for detecting miRNA-21, the defects of low detection sensitivity, high background signal and the like of the traditional method are overcome, the problems of complex living body and cell imaging technology, high price and the like are solved, and a new strategy and method are provided for living body and cell detection and in-situ imaging.

The invention relates to an enzyme-free electrochemical hydrogen peroxide sensor based on an AgNFs-Pt nano-composite material, and preparation. AgNO<3> solution is mixed with bovine serum albumin solution; after stirring, ascorbic acid solution is added; AgNFs solution is obtained by reaction; centrifugal washing is carried out; then, H<2>PtCl<6> solution is added into the washed material; after reaction, the solution is subjected to centrifugal washing, so that AgNFs-Pt solution is obtained; the AgNFs-Pt solution drops on the surface of the working electrode of the electrochemical sensor; andthus, the enzyme-free electrochemical hydrogen peroxide sensor based on the AgNFs-Pt nano-composite material is prepared. Compared with the prior art, an enzyme-free electrochemical hydrogen peroxidesensor construction method is simple, safe and rapid, and has very high sensitivity, wide linear detection range and low detection limit; a signal can be detected at very-low hydrogen peroxide concentration; simultaneously, a method for synthesizing a nano material required by assembling is green, environment-friendly, simple and easy to operate; the catalytic effect is good; and the material canbe used as a novel enzyme-free nano catalytic material.

The invention discloses an aflatoxin B1 detection method based on an up-conversion and black phosphorus nanosheet aptamer sensor, and relates to the field of food safety detection. The detection method comprises the following steps: step 1, preparing an amino-functionalized up-conversion nano material; 2, connecting an aflatoxin B1 aptamer to the surface of the amino-functionalized up-conversion nano material; 3, preparing a black phosphorus nanosheet; 4, dissolving the up-conversion nanoparticles with the aptamer connected to the surfaces obtained in the step 2 in a buffer solution, adding a dispersion solution prepared from the black phosphorus nanosheets obtained in the step 3, and carrying out incubating and combining to obtain a specific detection system; 5, establishing an aflatoxin B1 content detection standard curve; and 6, detecting the content of aflatoxin B1 in the sample. By constructing an aflatoxin B1 fluorescence detection system, high specificity and sensitivity detection of aflatoxin B1 in food is achieve, and the method has a wide concentration detection range and a low detection limit and has a good practical prospect.

The invention discloses a preparation method and application of a rare earth up-conversion fluorescence probe for detecting a DNA damage marker. The preparation method comprises the following specificsteps: premixing acid fuchsin and 8-OHdG dissolved in an acid buffer solution, incubating for a period of time, then adding an up-conversion nano material NaYF4: Er, Yb(NH2-UCNPs) subjected to surface amination modification, performing full mixing, and detecting under the irradiation of 980 nm excitating light to find that the fluorescence intensity difference (F-F0) of the system at 545 nm and the blank fluorescence intensity of a sample are in direct proportion to the negative logarithm of the addition concentration of 8-OHdG in order to achieve the quantitative detection of 8-OHdG. The constructed probe has strong background interference resistance and low toxicity, and can be used for detecting the fluorescence intensity of the sample under the irradiation of 980nm exciting light. Theconstructed detection method is high in sensitivity, wide in linear range, high in selectivity, stable in system, easy and convenient to operate, free of aptamer modification materials and low in cost.

The invention relates to a method for detecting the content of lead in tea leaves based on an upconversion-gold nanometer-magnetic nanometer specific system, and belongs to the technical field of food safety detection. The method comprises the following steps: firstly preparing and obtaining an upconversion nanometer material; adding ethyl alcohol, ammonia water, tetraethyl orthosilicate and 3-aminopropyltriethoxysilane to obtain an amino-functionalized upconversion nanometer material, and then preparing an adapter functionalized upconversion nanometer material; connecting a gold nanometer material and a magnetic nanometer material through an adapter complementary chain to obtain a gold nanometer-magnetic nanometer material solution, mixing with the adapter functionalized upconversion nanometer material solution to obtain a specific detection system, measuring fluorescence intensity signal characteristic values as vertical coordinates after a lead ion solution is added, establishing a lead content detection standard curve by taking lead ion concentrations as transverse coordinates so as to realize the measurement for the content of lead in tea leaves to be detected. According to the method, high-sensitivity specific detection of lead in tea leaves is realized by constructing a steady-state specific lead ion fluorescence detection system, and the method has the advantages of relatively wide linear detection range and relatively low detection limit and is good in application prospect.

The invention provides a flexible electrochemical glucose sensor and a preparation method thereof, the sensor is provided with a planar three-electrode composed of a working electrode, a reference electrode and a counter electrode which are located on the same plane of a polyimide film substrate, the working electrode is composed of a graphene layer and a copper oxide layer coated on at least one part of the surface of the graphene layer, the reference electrode is composed of a graphene layer and an Ag / AgCl conductive layer coated on at least a part of the surface of the graphene layer, the counter electrode is composed of a graphene layer, the working electrode, the reference electrode and the counter electrode are arranged at a predetermined interval from each other, and the Ag / AgCl conductive layer in the reference electrode is arranged facing the counter electrode. The sensor has the advantages of wide linear detection range, simplicity in processing and preparation, low production cost and easiness in batch production, is good in stability after being bent for multiple times, can be integrated with flexible temperature, pressure and strain sensors, and has wide application prospects in the fields of human health detection, biomedical treatment and the like.

The invention belongs to the field of food and environment safety detection, and particularly relates to a preparation method and application of an up-conversion luminescence flexible biosensor for diethylstilbestrol detection. The preparation method comprises the following steps: step 1, preparing an oleic acid coated up-conversion nano material; step 2, preparing an aminated up-conversion nano material; step 3, preparing a flexible up-conversion luminescence sensor; and step 4, preparing a bio-functionalized flexible up-conversion luminescence sensor. The sensor is used for detecting diethylstilbestrol, and detection of diethylstilbestrol content in food and environmental samples is realized by establishing a diethylstilbestrol content detection standard curve; through preparation of the up-conversion luminescence flexible biosensor and a detection method of diethylstilbestrol, rapid and economical detection of diethylstilbestrol in food and environmental samples is realized, and the up-conversion luminescence flexible biosensor has a wide concentration detection range and a low detection limit; meanwhile, the sensor has a renewable function and has a good practical prospect.

A gas sensor is disclosed, which includes two separate metal electrodes on a surface of a substrate and a semiconductor thin film deposited on the surface of the substrate and connecting the two metal electrodes. The semiconductor thin film contains zinc oxide or a mixed oxide of zinc and indium, and the zinc oxide or the mixed oxide of zinc and indium are in the form of nanowires which constitute a gas-sensing surface of the semiconductor thin film. The nanowires have a diameter of 50-900 nm. The present invention also discloses a method for detecting the presence of a NOx gas.

The invention belongs to the technical field of medical and biochemistry, and particularly relates to an adenosine deaminase measuring kit. The kit is composed of a reagent R1 and a reagent R2, wherein the reagent R1 comprises biobuffer, preservative, peroxidase, 4-aminoantipyrine, purine nucleoside phosphorylase, xanthine oxidase and water, and the reagent R2 comprises biobuffer, preservative, adenosine, N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline and water. The adenosine deaminase measuring kit conducts a test according to a continuous monitoring method, the main wavelength is 550 nm, and the kit has the advantages of being quick, sensitive, high in accuracy, specificity and stability and the like.

The invention discloses a method for detecting an organophosphorus pesticide by utilizing an MOFs@QDs material in a farmland environment. The method comprises the following steps of adding materials of 4-carboxyl phenyl benzene, zirconium chloride and benzoic acid into dimethylformamide and water, carrying out ultrasonic mixing, reacting in a reaction kettle, washing after naturally cooling, washing with methanol, and drying overnight to obtain a Zr-MOFs material, dissolving in water, ultrasonically mixing uniformly, adding quantum dots, mixing, ultrasonically centrifuging, washing and dryingto obtain a Zr-MOFs@QDs sensor, diluting the Zr-MOFs@QDs sensor with PBS, adding the organophosphorus pesticide, uniformly mixing, and detecting the fluorescence intensity in a microwell plate detector. With the method, the pesticide residue can be rapidly detected with high sensitivity, the good selective detection ability on parathion-methyl and parathion is provided, the detection limit is wideand is 0.005-2 mg / L, the detection efficiency is improved, and the application is wide.

The invention discloses a preparation method and application of magnetic porous nickel nanosheets, and relates to the technical field of inorganic mimic enzyme preparation. The preparation method comprises the following steps: dissolving NiCl<2>.6H2O and sodium citrate into deionized water to obtain a solution A; dissolving potassium tetracyanonickelate into deionized water to obtain a solution B;mixing the solution A and the solution B, stirring, standing for reaction, centrifuging, washing and drying to obtain a prussian blue homolog precursor; and calcining the precursor at high temperature in an inert atmosphere. According to the invention, the magnetic porous nickel nanosheets composed of a mesoporous graphite carbon ordered framework and uniformly dispersed nickel nanoparticles areprepared by a two-step method, have excellent strong magnetism and peroxide mimic enzyme activity, can realize hydrogen peroxide detection, magnetic separation and recycling, reduce the mimic enzyme use cost and environmental pollution risks, have the advantages of simple preparation process, easily available raw materials and low biological and environmental toxicity, and can be suitable for industrial large-scale production.

The invention discloses an ammonia gas sensing film formed based on HPTS and hydrotalcite nanosheets, and a preparation method thereof. The film is prepared from three components which are HPTS, hydrotalcite nanosheets and polyvinyl alcohol through a solvent evaporation method. HPTS molecules are fixed and dispersed by the hydrotalcite nanosheets and the polyvinyl alcohol, so that the vibration and rotation of the HPTS molecules are reduced, and the HPTS molecules show excellent fluorescence performance. The prepared ammonia gas sensing film has good light transmission and film-forming property, compared with an HPTS aqueous solution, the ammonia gas sensing film shows a wide linear detection range and a low detection limit when applied to ammonia gas sensing, the detection limit can reach 0.1-0.01 ppm, and the film has excellent repeatable detectability, fluorescence property and illumination stability.

The invention provides an enzyme-free pyruvic acid sensing detection method based on H2O2. The method comprises the following steps: adopting a three-electrode system, wherein an electrolyte solutionof the three-electrode system contains H2O2; adding sodium pyruvate with different concentrations into the electrolyte solution, and acquiring a standard curve of current response and sodium pyruvateconcentration by utilizing a chronoamperometry, wherein the working electrode of the three-electrode system is an H2O2 sensitive electrode; and comparing the standard curve according to the current response value generated by the to-be-detected sample solution containing H2O2 and pyruvic acid to obtain the concentration of sodium pyruvate. According to the method, the H2O2 consumption rate is monitored on line in real time by utilizing a Prussian blue modified electrode based on a carbonic acid removing reaction of pyruvic acid-H2O2, so that the concentration of pyruvic acid is quantitativelyobtained. The pyruvic acid concentration detection strategy adopting the method has a wide linear detection range, can effectively avoid the problems of poor repetitive effect and the like caused by poor stability of pyruvate oxidase, and can realize rapid and efficient real-time detection in a complex biological system, and the detection limit can reach 0.5 mM.

The invention discloses a method for quantitative determination of escherichia coli RNA, and a specialized standard substance and an application thereof. The method comprises the steps of (1) making a standard curve according to the following method, preparing standard substance diluents with different concentrations by using a RNA standard substance; reversely transcribing the standard substance diluents with different concentrations into cDNA; performing real-time fluorescence quantification PCR by using cDNA as templates; making the standard curve equation by using RNA copy number (or data-processed copy number, for example, log-base 10 of the copy number) corresponding to cDNA in the real-time fluorescence quantification PCR system and Ct values; and (2) extracting a total RNA of the escherichia coli, reversely transcribing the extracted total RNA into cDNA; performing the real-time fluorescence quantification PCR by using cDNA as the templates; and substituting the Ct values to the standard curve equation to obtain the RNA content of the escherichia coli. The method can be used for detecting small amount of the escherichia coli in the environment rapidly, and provides technical support for rapid detection of the active escherichia coli.