388 results about "Spectrofluorometer" patented technology

The invention relates to the detection field of microorganism foodborne pathogens and discloses a method for rapidly detecting and screening staphylococcus aureus, which adopts bio-functionalized superparamagnetic nano particles and immunized quantum dots to immunologically recognize target microorganisms to realize to specificity detection on the foodborne pathogens (staphylococcus aureus). According to the method, target bacteria can be rapidly separated from various samples, and enrichment is also performed efficiently; and besides, bacteria separated by the enrichment can be marked rapidly by fluorescence, so that the bacteria can be qualitatively identified by a fluorescence microscope and can be quantitatively detected by a fluorescence photometer. The method is convenient and simple to operate, and has high reliability and a low requirement on corollary equipment.

The invention relates to a detection technology of copper ions, and in particular relates to a preparation method of a reduced carbon quantum dot containing calcium alginate gel for detecting copper ions. The preparation method of the carbon quantum dot containing calcium alginate gel for detecting the copper ions comprises the following steps of: preparing fluorescent carbon quantum dots; neutralizing the fluorescent carbon quantum dots, adding sodium borohydride into the neutralized fluorescent carbon quantum dots to perform reduction; mixing deionized water with the neutralized fluorescent carbon quantum dots at equal volume, and adding sodium alginate into the mixture to obtain a sodium alginate sol; and spraying a calcium ion solution to the surface of the sol or soaking the sol into the calcium ion solution to perform crosslinking, and drying to obtain the calcium alginate gel. By using the characteristics that the carbon quantum dots have fluorescent characteristics, the fluorescence of the carbon quantum dots is enhanced after reduction, and the calcium alginate can enhance the fluorescent characteristics of the carbon quantum dots, when the copper ions are detected, the cost of an adopted fluorospectro photometer is low, the sample preparation and treatment steps are simple and easy to operate, and the detection sensitivity is high, so that the calcium alginate gel can be widely used for detecting the copper ions.

A polymer comprising a tagging material is provided wherein the tagging material comprises at least one organic fluorophore dye, or at least one inorganic fluorophore, or at least one organometallic fluorophore, or at least one semi-conducting luminescent nanoparticle, or combination thereof, wherein the tagging material has a temperature stability of at least about 350° C. and is present in a sufficient quantity such that the tagging material is detectible via a spectrofluorometer at an excitation wavelength in a range between about 100 nanometers and about 1100 nanometers. Further embodiments of the present invention include a method for identifying a polymer and an article comprising a polymer wherein the polymer contains the aforementioned tagging material.

The present invention is fast detection method of aflatoxin B1 in food and feed. The fast detection method includes the following steps: adding ground sample to be tested in 2-10 g in test tube, adding methanol-sodium chloride aqua of 50-80 % concentration in 10-25 ml, ultrasonic extraction in water bath at 40-60 deg.c, and suction filtering to obtain filtrate in 4-10 ml; adding re-distilled petroleum ether in 2-4 ml into the filtrate, shaking, letting stand to laminate, taking the lower layer of solution in 1-4 ml and adding pure water in 4-20 ml; adding to micro immunoaffinity column of aflatoxin B1, washing with methanol aqua of 10-40 % concentration in 5-10 ml, eluting with methanol in 0.5-2.0 ml, collecting the eluted liquid, adding test agent A in 0.2-1.0 ml; and detecting in fluorescent spectrophotometry or similar instrument. The present invention has the features of simple process, high detection precision and stability, fast detection speed and high safety.

The invention relates to a assaying method for the aflatoxin, specifically saying, it is a method of adopting immunity affinity column and fluorophotometer prepared by monoclonal antibody of aflatoxin to assayt the aflatoxin in the food, which belongs to biocytology and microbacteria toxic metabololic products assaying method technical field.The method is as following: first, preparing monoclonal antibody by the steps involving: immunizing mouse, cell fusion, screening crossing tumour and obtaining the cell line of the crossing tumourc, gathering monoclonal antibody, etc, then using the abovementioned monoclonal antibody to prepare the immunoaffinity column, last, after milling the food and feed, extracting the aflatoxin out of it with methanol/water solution, after filtering, letting the liquid sample flow through the affinity column to be refined, successively, eluting the AFT from the affinity column with methanol, and assaying the content of aflatoxin in the sample with a fluorophotometer.

The invention discloses a dual-functional probe and a preparation method and application in detection of a G-quadruplex structure thereof. The probe is simple to prepare, readily available, and stable in structure, and can be used for the specific detection of G-quadruplex nucleic acid secondary structure, and fast detection of the secondary structure of a DNA sample in a solution according to an ultraviolet and visible absorption spectrum, a fluorescence spectrophotometer, or direct visual inspection of naked eyes. The method for detecting the G-quadruplex nucleic acid secondary structure by the probe has the advantages of simple and convenient operation, excellent and fast selectivity, and visibility by naked eyes, and overcomes the defects of high cost and equipment requirement, relatively complex technical operation and the like of other detection methods.

A preparation method of a fluorescent carbon quantum dot probe for detecting beryllium in water comprises the following steps: preparing a citric acid solution with a concentration of 0.04 g/ml; weighing urea, adding the urea into the above citric acid solution, uniformly stirring to obtain a mixed solution, wherein the urea concentration is 0.01-0.04 g/ml; transferring the above mixed solution into a hydro-thermal reaction vessel, reacting at 200-240 DEG C, naturally cooling the reaction vessel to room temperature to obtain a brown aqueous solution; performing centrifugation by a centrifuge and dialysis in order of the brown aqueous solution, then concentrating the brown aqueous solution by a rotary evaporator, and finally drying in a vacuum drying oven to obtain a solid viscous substance. The product of the invention makes use of the fluorescence characteristic of carbon quantum dots; detection of beryllium ion content is carried out by a fluorescence spectrophotometer, which is low in cost; the sample preparation and treatment steps are simple and easy to operate; the detection selectivity and sensitivity are high; the product of the invention is widely applicable to beryllium ion detection.

The invention discloses a magnetic molecularly imprinted polymer-fluorescence analysis method, relates to a rapid detection of pesticides, and aims to solve the problem of difficulty in preparation of small molecular natural antibody in the conventional quick detection method. The method comprises the following steps: 1, preparing polyethylene glycol and oleic acid-coated magnetic nanoparticles; 2, preparing a magnetic molecularly imprinted polymer of triazine pesticides; 3, determining a fluorescence signal by using a fluorescence spectrophotometer. The common natural antibody which is difficult to prepare in the normal quick detection method is substituted by using a magnetic molecularly imprinted biomimetric material; quick detection of a non-immune method of the triazinemicromoleuclar pesticides is technically realized through competitive combination of the pesticide molecules and the fluorescence probe on the magnetic imprinting. The method is used for quickly detecting the residue of the triazine pesticides.

The invention relates to a method for detecting the total number of bacteria based on the fluorescent method of NADH, in particular to a novel method for rapidly detecting the total number of colon bacteria based on the fluorescent characteristic of the NADH in a colon bacteria cell and the stable-content characteristic of the NADH in the colon bacteria cell, which comprises the processes of extracting NADH in the colon bacteria cell, detecting the content of the NADH in the colon bacteria cell, detecting the fluorescent intensity of the NADH in the colon bacteria cell with a fluorescent spectrophotometer and rapidly detecting the total number of bacteria. The fluorescent detection limit of the NADH is 1 nM, and the content of the NADH ranges from 10 nM to 80 microns and keeps a favorable liner relationship (R = 0.9905) with the fluorescent intensity. The colon bacterial cell is obtained in a decentering way, the NADH in the colon bacteria cell is extracted in a Tris-HCl method, the fluorescent intensity of extracting solution of the NADH is extracted with the excitation wavelength of 342 nm and the emission wavelength of 461 nm, and the colon bacteria of 10 cfu/mL can be detected in one hour. The method adopts novel detection theory, has rapid detection speed and good repeatability, is sensitive and easy, is suitable for quantitatively detecting the number of colon bacteria in the fields of food sanitation and safety, environment detection, and the like, and can replace the traditional method for detecting the number of living cells.

The invention relates to a method for high selective identification of aluminum ions and tin ions in water phase by using a water-soluble porphyrin probe. According to the method, an ultraviolet-visible spectrophotometer and a fluorescence spectrophotometer are used for detecting the characteristic absorption peak and emission peak of water-soluble porphyrin solution to red shift to certain wavelength respectively to identify the existence of aluminum ions or tin ions in water phase; and fluorescence intensity of human lung carcinoma A549 cells are observed under an upright fluorescent microscope to judge the existence of aluminum ions. In the invention, the sensitivity is high, and rapid detection can be realized; the porphyrin probe has a simple structure and is easy to prepare, and both excitation wavelength and emission wavelength are within visible region; the operation is simple, the fabrication cost is low, and the reagent used and the operation process have no toxic and side effects; and the probe has good selectivity to aluminum ions or tin ions, metal ions such as natrium ions, kalium ions, magnesium ions, copper ions, lead ions and the like have no interference on detection, and the invention can realize detection of aluminum ions in cells.

The invention discloses a fluorescence labeling polyether carboxylic acids scale inhibitor and a preparation method thereof, which relates to the preparation of the fluorescence labeling polyether carboxylic acids scale inhibitor which has fluorescent tracing but no phosphorus, can realize the online detection and automatic dosing of the phosphorus-free scale inhibitor, and is applicable to the scale inhibition and the fluorescent tracing and monitoring of calcium phosphate in an industrial circular cooling water system. The fluorescence labeling polyether carboxylic acids scale inhibitor is obtained by the free radical trimerization of vinyl-contained unsaturated double bond monomer, allyloxy polyether carboxylic acid monomer or carboxylate monomer and allyloxy monomer containing pyrene fluorophore. The structural formula is as shown: with the dosage of 2-25 mg/L and at the temperature of 40-80 DEG C, the inhibition rate of Ca3(PO4)2 is 92.00-99.89 percent. When the dosage of 2-30 mg/L is measured by a fluorescence spectrophotometer (EX460nm, EM510nm), the fluorescence intensity is 25-400 degrees.

The invention relates to a multiplex flow type detection device for micro-droplet fluorescence image and spectrum scanning. A flowing focusing principle is utilized to generate micro-droplet in a microchip; a contracting runner is adopted for realizing the focusing of the micro-droplet; the laser emitted from a laser device is expanded by an expanding mirror and then is reflected by a dichroic mirror; an objective lens is adopted for focusing the single micro-droplet in the contracting runner; after a fluorescent material in the micro-droplet is excited, the emitted fluorescent light is collected by the objective lens and then passes through the dichroic mirror and is split into two beams by a beam splitter mirror; one beam passes through a light filter and then is imaged on EMCCD, and the fluorescence image is recorded; after the other beam passes through a transmission type diffraction grating, the light in different wavelengths is diffracted to different directions so as to form a frequency band; a fluorospectro photometer is used for collecting and realizing the spectrum scanning. The device provided by the invention can be used for realizing the multiplex flow type detection for micro-droplet fluorescence image and spectrum scanning in the microchip runner, the complete optical information of the micro-droplet can be acquired and the application requirement for the fluorescence multiplex encoding technique in the micro-droplet can be met.

The invention discloses preparation of red fluorescent carbon nanodots, and a method used for detecting ferric ions and ascorbic acid, and belongs to the field of metal ion detection. According to the preparation, citric acid, thiourea, and acetone are taken as raw materials, are delivered into a hydro-thermal reaction kettle, and are reacted for 8h at 160 DEG C so as to obtain the red fluorescent carbon nanodots. The method comprises following steps: a carbon nanodot solution is prepared; ferric ion solutions of different concentrations are added, and the change of the fluorescence intensity is detected using a fluorospectro photometer; a curve used for representing the change of fluorescence intensity with ferric ion concentration is drawn, and fitting is carried out so as to obtain a fitting formula; reduction of ferric irons can be realized with ascorbic acid, so that ascorbic acid solutions of different concentrations are added to recovery fluorescence, a curve used for representing the change of fluorescence intensity with ascorbic acid concentration is drawn, and fitting is carried out. The method can be used for detecting the concentrations of iron ions and ascorbic acid, and is simple and convenient.

The invention discloses a value defining method for a microsphere fluorescent intensity standard substance. The method comprises the following steps: (1) preparing a microsphere fluorescent intensity standard substance; (2) measuring purity of fluorescein powder to calculate and prepare fluorescein standard mother liquid; (3) regulating a fluorospectro photometer; creating a calibration curve of an instrument fluorescent responding value and fluorescein density; (4) measuring granular quantity density of the microsphere fluorescent intensity standard substance; (5) measuring fluorescent responding value of a sample; calculating fluorescein density of the sample and fluorescent molecule quantity MESF carried by each microsphere fluorescent intensity standard substance granular. The value defining method is provided with favorable accuracy, reliability and traceability of value.

The invention relates to a quantum dot fluorescent anti-counterfeiting paper and a manufacturing method thereof. The invention first provides the quantum dot fluorescent anti-counterfeiting paper, which contains quantum dots. The invention further provides the manufacturing method of the quantum dot fluorescent anti-counterfeiting pape; and the method comprises the following steps of: compounding the quantum dots into a carrier material; and in the papermaking process, adding the carrier material compounded with the quantum dots to the paper, so as to obtain the quantum dot fluorescent anti-counterfeiting paper. According to the invention, the application of a quantum dot fluorescent material in counterfeiting prevention of papers has the advantages of advanced technology, strong anti-counterfeiting capacity, large counterfeiting difficulty and so on. Through the adoption of the quantum dot fluorescent anti-counterfeiting paper provided by the invention, public identification counterfeiting prevention can be achieved by using a visible fluorescence color of a common fluorescent ultraviolet lamp and spectral analysis can be also carried out on the paper by using a fluorospectro photometer so as to achieve machine readable counterfeiting prevention, so that the anti-counterfeiting level of the paper is increased.

The invention relates to a fluorescence detection method for trace tetracycline antibiotics. According to the method, by utilizing the combined action of tetracycline antibiotics molecules and the specificity of an aptamer thereof, an amplification action of a rolling ring amplification signal and high selection action of a graphene molecular beacon as well as combining a fluorescence spectrophotometer, the fluorescence signal of the graphene molecular beacon is obtained, so that quantitative detection of trace tetracycline antibiotics can be realized. According to the method, a plurality of defects of the prior art such as complexity in detection are overcome, the sensitivity and selectivity are improved, and a new method is provided for detection of other small molecule substances or pollutants.

The invention relates to a homocysteine Hcy kit based on an aptamer fluorescence probe; at the same time, the invention also relates to a method for determination of the concentration of homocysteine Hcy, and a determination reagent composition and components, and belongs to the technical field of medical examination and determination. The kit comprises the main components: an erythrocyte lysate, a phosphate buffer solution PBS, a homocysteine Hcy standard substance, and the homocysteine Hcy aptamer fluorescent probe; through blood sample cracking and mixed egg fertility treatment, and with combination of a fluorescence spectrophotometer for detection, the value of the concentration of the homocysteine Hcy is measured and calculated. The kit has the advantages of simple sample treatment, simple and convenient operation, short detection time, strong detection specificity, high sensitivity, high repeatability of detection results and the like.

The invention provides a method for detecting the specificity of trinitrotoluene. The method comprises the following steps of: under a nitrogen protection condition, adding 67.8mg of cysteine into 150mL of ultra pure water containing 96.5mg of Cd(AC)2; adjusting a pH value of the solution to be 11.0 by using 0.5M NaOH; adding 223.5mg of sodium citrate and 17.9mg of Na2TeO3 respectively into the solution; under a condition of introducing nitrogen, adding 16.5mg of NaBH4; finally, transferring 25mL of the solution to a high-pressure reaction kettle to perform reaction at the temperature of 160 DEG C so as to obtain the solution of CdTe quantum dots with different grain sizes; and adding a condensed detection sample into the solution of CdTe quantum dots and reacting for 2 hours, and detecting the sample by using a spectrofluorometer. The method has the advantages of high sensitivity and specificity, short detection time, easy sample treatment and good application prospect.

The invention belongs to fluorochrome molecular luminescence domain, concretely relates to a method for getting identical dye molecule of the identical base emit fluorescent lights with different colors by constructing different structural surfaces of backing materials and accordingly introducing coherent conditions of organic light-emitting molecule and oligomer light-emitting molecule. The said method includes the following steps: selecting inorganic background or polymeric background and performing treatment for substrate surface; constructing surfaces with microstructure by layered self-packaging, vapour deposition, LB film technology, nano autogram or stamping-cure selective elution technique for the treated background; depositing film of identical dye molecule on inorganic background or polymer background of micro-structural surface with vacuum degree of 1*10-4-5*10-4Pa and electric current of 5-10A; agitated by ultraviolet light, fluorescent lights with different colors can be observed on molecular surface of identical dye by fluorescence spectrometer or fluorescence microscope.

The invention relates to a quick pre-warning method for organic pollution of surface water. The pre-warning method comprises the following steps: (1) collecting surface water as raw water; (2) filtering the raw water through a micro-pore filter film; (3) taking 1-1.5 L of the filtered water sample for concentration through a reverse osmosis device to obtain the concentrated water sample; (4) taking the concentrated water sample obtained in step (3) into a fluorescent cuvette, and placing into a sample cell in a fluorescence spectrophotometer for three-dimensional fluorescence spectrum scan to obtain the three-dimensional fluorescence spectra of the concentrated water sample; (5) preparing the standard water sample according to the toplimit of the Standard of Drinking Water, and obtaining a standard spectra after concentration through the reverse osmosis device and scan through three-dimensional fluorescence; (6) comparing the standard spectra with the three-dimensional fluorescence spectra of the water sample. If the fluorescence intensity of the three-dimensional fluorescence spectra of the water sample is less than or equal to that of the standard spectra, the organic pollution of the surface water is confirmed to be under the standard; whereas, the organic pollution of the surface water is confirmed to exceed the standard. The pre-warning method is quick, convenient, easy to operate and high in efficiency.