47results about How to "Improve detection limit" patented technology

The invention relates to the field of mass spectrometry, in particular to a double-helix ion funnel with an auxiliary electrode in ion transmission. The double-spiral ion funnel with the auxiliary electrodes comprises two spiral electrodes, each spiral electrode is provided with a constant inner diameter section and a conical inner diameter section which are connected in the ion transmission direction, the four auxiliary electrodes are arranged at an outlet of the conical inner diameter section, the four auxiliary electrodes are matched with the double-spiral electrodes, positive electrodes and negative electrodes are alternately arranged, and the two spiral electrodes are arranged in a staggered mode. And a hexapole rod structure is formed at the outlet of the double-helix ion funnel to improve a fringing field. Under the cooperation of the auxiliary electrode and the double-helix electrode, the influence of a fringing field on the double-helix electrode structure is greatly improved. And the transmission efficiency of ions with low and medium mass-to-charge ratios in a coarse vacuum region is enhanced, and the transmission efficiency is hardly influenced by potential traps. Meanwhile, the ionic strength is enhanced, and lower detection limit and higher sensitivity can be realized.

The present invention discloses a thermal analyzer with low-temperature adsorption function, including an axial flow fan, a radiator, a heat preservation box, a refrigeration sheet, a cold storage sheet, a six-way valve, a driving motor, a carrier gas flow controller, a secondary adsorption tube, a primary adsorption tube, a primary heating body, a purge gas flow controller, a vent pipe, a detection device and a heating wire. The axial flow fan is provided with a radiator, and the axial flow fan is provided with a heat preservation box. The heat preservation box is provided with a refrigeration sheet and a cold storage sheet, and the cold storage sheet is provided on the refrigeration sheet. A thermal analyzer with low-temperature adsorption function is manufactured by adopting the above technical scheme. The secondary thermal analysis technology is adopted to make the peak shape sharper and improve the detection limit. Since the secondary analysis device has the advantages of small size, low-temperature concentration and rapid heating, the system error is reduced, the unit concentration is increased, and the detection limit is greatly improved.

The invention discloses a multi-reflection cavity enhanced Raman system and a use method. The multi-reflection cavity enhanced Raman system comprises a concave mirror, a converging lens and an optical fiber bundle, the optical fiber bundle comprises a plurality of optical fibers which are horizontally arranged, a converging lens, a parallel lens, a reaction part and a concave mirror are distributed at the input end of each optical fiber, and a first lens and a first retroreflector as well as a second lens and a second retroreflector are arranged at the two ends of the reaction part. Then the laser signal reacts with the to-be-detected gas to generate a Raman signal, a part of the Raman signal is reflected by the concave mirror, and then the Raman signal is converged in the optical fiber by the converging lens and the parallel lens to be received; raman signals excited on the horizontal plane are matched with the horizontally arranged optical fibers, so that the receiving effect is good; the intensity of the laser signal at the reaction position is high, so that the intensity of the generated Raman signal is high. Therefore, the design has a relatively good receiving effect on the Raman signal, and the intensity of the received Raman signal is relatively high.

The invention discloses a bimetallic / carbon nanotube compound modified glassy carbon electrode as well as a preparation method and application thereof, and belongs to the technical field of electrochemical analysis. The bimetallic / carbon nanotube compound modified glassy carbon electrode provided by the invention comprises a glassy carbon electrode substrate and a bimetallic / carbon nanotube compound compounded on the glassy carbon electrode substrate, the bimetallic / carbon nanotube compound is prepared from nickel-cobalt bimetallic nanoparticles and a multi-walled carbon nanotube. The prepared bimetallic / carbon nanotube compound modified glassy carbon electrode has excellent electrocatalytic activity, has the advantages of good stability, low detection limit and high sensitivity and selectivity in the process of determining paracetamol, can realize on-site rapid detection of paracetamol, has the advantages of being convenient to carry and simple to operate, and has a wide application prospect. Wide application prospects are realized in medicine safety and clinical medical treatment.

The invention belongs to the technical field of medical chemical component detection, and discloses a method for determining lead salt in a sulfadiazine zinc raw material, which comprises the following steps: S1, measuring a lead single element standard solution, and diluting with a nitric acid solution to obtain a linear solution containing different concentrations of lead; s2, weighing a sample, and adding nitric acid for digestion and dissolution to obtain a sulfadiazine zinc test solution; s3, measuring the same amount of nitric acid in the step S2, and performing digestion and dissolution to obtain a sample blank solution; s4, respectively injecting the linear solutions in the step S1 into an atomic absorption spectrophotometer, and making standard koji according to a preset heating program; and S5, respectively injecting the sulfadiazine zinc test solution and the sample blank solution into an atomic absorption spectrophotometer, and determining the lead content in the sulfadiazine zinc according to a preset heating program. The problems that an existing method is low in sensitivity and cannot meet limit requirements are solved.

The invention discloses a preparation method of a low-dimensional composite material for electrochemical sensing detection of nitrite, and relates to the technical field of low-dimensional materials. The preparation method comprises the following steps: by taking selenium powder as a reducing agent, reducing phosphomolybdic acid under specific hydrothermal reaction conditions, and after the reaction is finished, cooling, centrifuging and drying to obtain the MoO3-coated MoSe2 nano composite electrode material. The one-dimensional / two-dimensional structure MoO3atMoSe2 nano composite electrode material prepared by the invention has the advantages of strong specific recognition capability on nitrite, long service life, high sensitivity and excellent detection limit.

The invention discloses a biosensor based on an ultraviolet light triggered bio-barcode release technology (OBCA) and construction and application of the biosensor. The biosensor comprises nucleic acid functionalized silver nanoparticles, nucleic acid functionalized magnetic beads and a CRISPR (clustered regularly interspaced short palindromic repeats) / Cas12a detection system, the DNA bar code modified on the surface of the silver nanoparticle contains a light cleavable linker, a CRISPR / Cas12a activation sequence and a target capture sequence I, and a DNA capture probe containing a target capture sequence II is fixed on the surface of the magnetic bead through biotin-streptavidin action. During detection, target miRNA mediates two capture sequences to form a sandwich compound, after magnetic separation and thermal denaturation elution, 365nm ultraviolet radiation releases DNA bar code fragments, and the Cas12a trans-cleavage fluorescence quenching reporter probe is activated to generate a signal. According to the method, nucleic acid amplification and reverse transcription are not needed, the detection limits of miR-21, miR-155 and mi-210 respectively reach 158.94 aM, 763.56 aM and 197.82 aM, single-base mismatch and precursor miRNA can be distinguished, the serum sample detection result is highly consistent with that of RT-PCR, and the method is suitable for high-sensitivity quantitative detection of miRNA.

The invention discloses a dual-mode detection kit for highly sensitive detection of ERalpha based on HRP-streptavidin. The dual-mode detection kit comprises the following raw materials: a glassy carbon electrode, 1-AP-CNHs, AuNPs, Sh-Apt, MCH, Bio-Ab, and HRP-streptavidin. The invention successfully constructs an electrochemical detection kit for detecting ERalpha with high sensitivity on the basis of the 1-AP-CNHs / AuNPs composite material. According to the invention, due to the redox activity of HRP-streptavidin, the HRP-streptavidin and H2O2 are subjected to redox reaction to generate a current signal; in addition, hydrogen peroxide can be catalyzed to generate. OH free radicals, and the free radicals can oxidize TMB to generate blue products, so that colorimetric reaction is initiated, and ERalpha can be detected more accurately. The electrochemical-colorimetric dual mode of the 3D 1-AP-CNHs / AuNPs composite material and the HRP-streptavidin for high-sensitivity detection of the ERalpha disclosed by the invention greatly improves the detection accuracy. The kit has the advantages of good selectivity, strong stability, high sensitivity, anti-interference performance, environmental protection and the like.

The invention discloses a PSR primer for identifying bacillus subtilis based on a specific gene target, a kit and a detection method. The specific detection target is obtained through comparative genomics and bioinformatics mining, is selected from a yhjO gene, and has the characteristics of high precision and strong specificity at the same time. A specific primer is designed for a newly excavated specific detection target yhjO gene of the bacillus subtilis, a PSR detection method of the bacillus subtilis is established, and the detection method has the advantages of being high in sensitivity, good in specificity, high in reaction speed, low in cost and easy to operate.

Use of a compound, microarray chip substrate, microarray chip and use and method thereof. The present application provides use of a compound, or a geometric isomer, tautomer, isotopically labeled, hydrate, solvate or salt thereof in chip surface modification. Also provided is a microarray chip substrate modified by the compound, and a microarray chip comprising the microarray chip substrate. The microarray chip substrate of the present application can greatly improve the surface modification function by surface modification, improve nucleic acid synthesis yield, amplify detection signal, and avoid non-specificity and cross-talk. It has a wide application prospect.

The invention discloses a chitosan-modified graphene field effect transistor biosensor and application thereof. The invention uses a silicon dioxide / silicon dioxide (Si / SiO2) substrate modified with a source and a drain as a substrate, transfers graphene as a sensing channel to the substrate surface to form a GFET, uses CTS as a linker and is electrostatically adsorbed on the sensing channel surface, and uses an anti-procalcitonin antibody (anti-PCT) as a probe to be modified on the CTS surface through glutaraldehyde cross-linking to specifically capture PCT; the invention can detect the procalcitonin in a manner of causing a voltage shift of the CTS-GFET Dirac point after PCT specifically binds to the PCT antibody on the CTS-GFET channel surface, has high detection sensitivity and specific selectivity, and its detection sensitivity for procalcitonin can reach 0.82 ag / mL, which is 3 times higher than the detection limit of a traditional GFET.

The invention provides an electrochemical electrode for detecting hydrogen peroxide concentration and a detection device and method thereof. The device comprises a rotating electrode, a static electrode and a reference electrode, the rotating electrode comprises a driving motor, a rotating rod and a rotating body which are connected in sequence, a first current collector is arranged in the rotating body, and a detection electrode is embedded in the bottom of the rotating body; the static electrode comprises an insulating shell, a second current collector and a counter electrode, the second current collector is arranged in the insulating shell, and the counter electrode is embedded in the top of the insulating shell and is arranged right below the detection electrode in parallel. The invention also provides a hydrogen peroxide concentration detection device provided with the electrochemical electrode and a method for detecting the hydrogen peroxide concentration on the detection device. In the hydrogen peroxide concentration detection process, the hydrogen peroxide concentration on the surface of the detection electrode is kept relatively stable and is close to the concentration of the whole hydrogen peroxide solution, the detection result error is small, the reproducibility is good, the detection limit is low, the detection range is large, and the detection efficiency is high.

The present invention discloses a three-terminal flexible adaptive tactile sensor and a manufacturing method, comprising a first end (1), a second end (2) and a third end (3) from top to bottom; the first end (1) is a surface electrode, used to contact with the outside world to generate electrons; the second end (2) is an intermediate electrode, used to conduct electrons; the third end (3) is a bottom electrode, one end of the first end (1) is connected to the positive electrode of a power supply through a wire, and the other end of the first end (1) is connected to a host computer through a wire; one end of the second end (2) is connected to the host computer; one end of the third end (3) is connected to the negative electrode of the power supply through a wire, and the other end of the third end (3) is connected to the host computer through a wire. The present invention can self-adjust the corresponding modulus according to different pressure conditions, that is, the response is completed in the first stage under different moduli, thereby achieving an adaptive effect.

The invention belongs to the technical field of albumin analysis, and particularly relates to a lateral flow immunoassay device for albumin detection. According to the technical scheme, a transparent glass substrate is adopted to replace an existing plastic back plate, and silanization modification is carried out on partial area of the transparent glass substrate so as to fix an antibody; the lateral flow immunoassay device for albumin detection, which is prepared by replacing an antibody fixed on a nitrocellulose membrane, can solve the technical problems recorded in the prior art in a lateral chromatography immunoassay method, and has the advantages of improving the detection concentration range and detection limit of a low-concentration albumin sample, improving the detection sensitivity, reducing the use amount of colloidal gold, reducing the cost and the like. The technical effect of biological detection of albumin detection is enhanced.

This invention discloses a three-modal, two-color lateral flow immunochromatographic test strip based on phenylboronic acid gold nanoflowers and its detection method. This test strip can simultaneously perform qualitative and quantitative tests, with the qualitative mode capable of detecting concentrations as low as 10. 3 Pathogenic microorganisms at CFU / ml; the lowest detectable concentration in colorimetric quantification mode is 10. 3 Pathogenic microorganisms at CFU / ml; the lowest detectable concentration using photothermal and Raman quantitative modes is 10. 2 The invention detects pathogenic microorganisms at cfu / ml levels; the detection can be completed within 15 minutes, and the test results can be observed with the naked eye; the three-modal LFIA improves the sensitivity, accuracy, flexibility and practicality of the detection. The invention has strong specificity for pathogenic microorganisms, high sensitivity, convenient and fast detection process, and safe and reliable test results.

This invention discloses a wide dynamic range substrate reagent, belonging to the field of biological detection reagent technology. The reagent consists of the following components: citric acid, 9.6 g / L; 3,3',5,5'-tetramethylbenzidine, 0.29 g / L; 3% hydrogen peroxide solution, 3 mL / L; 1 g / L polyvinyl alcohol; 0.5 g / L copovidone W-735; 0.5 g / L dimethyldiallylammonium chloride-acrylamide copolymer; 1 g / L PVP K30; and Tween 20, 0.005 g / L. mL / L; polyethylene glycol 10g-50g / L; pure water, balance. This invention, by adding specific polyethylene glycol and synergistically combining with other components, significantly reduces the reagent background signal and improves detection sensitivity; effectively broadens the detection dynamic range and increases the detection upper limit of high-concentration analytes; improves the linear correlation between signal and concentration; and enhances the thermally accelerated stability of the reagent. This reagent has comprehensive performance and is especially suitable for ELISA detection systems with high sensitivity and wide detection range.

The present invention provides a method for detecting the content of lead in lubricating oil, and relates to the technical field of lead content detection in lubricating oil. The method comprises: using a rotating disk motor emission spectrometer to collect spectra of standard oils with known lead content under preset collection conditions, and collecting each standard oil multiple times; performing first-order differential and smoothing processing on the collected standard oil spectra, and performing multivariate scattering calibration; using a principal component regression method to establish a correlation model between the lead content and the standard oil spectra under specific parameters; using a rotating disk motor emission spectrometer to collect spectra of lubricating oil samples under the same collection conditions as the standard oil; inputting the lubricating oil sample spectra into the correlation model to obtain the content of lead in the lubricating oil sample. In this way, the effective information of many spectral lines of the lead element can be fully utilized, and the detection limit of the lead element of the rotating disk motor emission spectrometer can be effectively improved.

The invention discloses a method for detecting the content of lacosamide particles through high performance liquid chromatography, and belongs to the technical field of detection and analysis. The method for detecting the content of lacosamide particles by high performance liquid chromatography comprises the following steps: respectively injecting a reference solution and a test solution into a liquid chromatograph, recording chromatograms, and calculating the content of lacosamide by peak area according to an external standard method. The method solves the problem of poor linearity and repeatability during lacosamide particle content detection, has remarkable advantages, and fills the blank of lacosamide particle content detection in China. Besides, the method is simple and easy to operate, good in specificity, high in precision and sensitivity, stable, reliable and good in durability, various chromatographic conditions are matched with one another, and the method can be used for quality control of the lacosamide particles and is suitable for industrial production.

The invention discloses a NO2 differential absorption Sham imaging laser radar based on a wavelength switchable laser. It comprises a wavelength switchable external cavity compression blue light laser and a Sham imaging unit. The output beam of a high-power blue light diode laser in the external cavity compression blue light laser passes through a first cylindrical lens, a second cylindrical lens, a blazed grating, a plane reflector and a polarizer respectively. After passing through the polarizer, the beam is divided into two beams of light: one beam is injected into a beam shaper as a main energy beam, and the laser output from the beam shaper is the output laser of the wavelength switchable external cavity compression blue light laser, which is injected into the atmospheric space to be measured; the other beam is injected into a wavelength meter as a test beam, and the wavelength meter is connected to a computer; the invention utilizes the wavelength switching characteristics and high power characteristics of the external cavity compression blue light laser, reduces the cost of the gas differential absorption Sham imaging laser radar, and improves the system stability.

The invention discloses a double-ball coupling type photoacoustic multi-gas sensor, which comprises a shell, a double-ball coupling type photoacoustic cell is arranged in the shell, the double-ball coupling type photoacoustic cell comprises a large ball body and a small ball body which are coupled with each other, the maximum sound pressure is located in the whole small ball body, and the maximum sound pressure is located in the whole small ball body. The tail end of the small sphere is provided with a cantilever beam sonic sensor used for detecting a photoacoustic signal, and the cantilever beam sonic sensor is internally provided with a cantilever beam which is in positive correlation with the concentration of gas in the photoacoustic cell. The double-ball coupling type photoacoustic cell is composed of two mutually-coupled balls, the low-concentration gas detection capacity is remarkably improved, multi-gas detection can be achieved, and due to the fact that the vibration amplitude of the cantilever beam is in positive correlation with the gas concentration in the photoacoustic cell, the gas concentration in the photoacoustic cell can be accurately detected by accurately detecting the vibration amplitude of the cantilever beam. The gas concentration change in the photoacoustic cell can be effectively reflected, and the photoacoustic cell has the advantages of low detection limit, high Q value, strong stability, high sensitivity, good signal-to-noise ratio, low cost and the like.

The invention discloses a toluene steam detection gas sensor and a preparation method thereof, the sensor takes a porous Co3O4 material synthesized by a mixture of a cobalt compound, urea and a solvent through hydrothermal and annealing as a sensitive body, and the interaction of gas on the surface of the sensor is improved through a surface pore-forming technology. The gas sensor is deposited on the surface of a planar gold interdigital electrode through a coating process to prepare a gas sensitive element. The obtained sensitive element has good response to toluene steam, and the detectable actual concentration is as low as 1 ppm. In addition, the sensor also has the capability of resisting interference of other organic steam, and has better selective response to toluene steam. The kit can be used as a beneficial tool for preliminary diagnosis of lung cancer clinically.

The invention discloses a capture probe for detecting human immunodeficiency virus type 1, a plurality of capture probes are obtained by adopting imbricated design according to a plurality of reference genome whole-genome sequences of standard strains and subtype strains of HIV in an NCBI database, after a total RNA library is constructed, the capture probes are used for capturing the HIV whole-genome library, and the HIV whole-genome library is used for detecting the human immunodeficiency virus type 1. The probe sequence densely and repeatedly covers all areas of each reference genome, and the design parameters of the probe are as follows: the length is 120nt, and the imbrication frequency is 3X-6X Tiling. The invention further provides a kit comprising the capture probe and application of the kit. According to the capture probe, sequencing data is optimized, invalid data redundancy is reduced, sequencing efficiency is improved, and sequencing cost is reduced. Through whole genome sequencing, drug-resistant mutation and low-frequency mutation of a low-load sample can be detected, typing and virus load can be detected at the same time, the detection cost is remarkably reduced, and the detection efficiency is improved.

The invention discloses a method for identifying unknown organic phosphodiesters in an environment based on a diazomethane derivatization technology. The method comprises the following steps: S1, establishing an OPDEs suspicious database; s2, carrying out methyl derivatization on the OPDEs to be detected; s3, carrying out suspicious screening on the OPDEs; s4, determining characteristic fragments of the derivatization OPDEs; and S5, carrying out non-targeted screening on the OPDEs. According to the suspicious-non-targeted comprehensive screening method for the unknown OPDEs in the environmental sample, the limitation that an OPDEs analysis method in the environment can only recognize known types of OPDEs can be solved, and comprehensive recognition of the unknown OPDEs in the environmental sample can be achieved.

This invention discloses an autocorrelation active fiber cavity ring-down quasi-distributed temperature sensing method and apparatus. The sensing apparatus includes a light source, a first three-port circulator, a plurality of active fiber cavities, a reference CFBG, and a photodetector. The light source is connected to the first three-port circulator, which is also connected to the reference CFBG. The first three-port circulator is connected to the active fiber cavities. Each active fiber cavity consists of a CFBG, a second three-port circulator, an erbium-doped fiber amplifier, a first fiber coupler, and a second fiber coupler. The plurality of active fiber cavities are connected in series, and the reflected light signals are cyclically transmitted and amplified through the plurality of active fiber cavities to achieve multi-point temperature detection. The output end of each active fiber cavity is connected to the photodetector, and the output end of the photodetector is connected to a data acquisition card. The data acquisition card is connected to an external terminal.

The present invention relates to the field of mass spectrometry, and in particular to a double helix ion funnel with an auxiliary electrode in ion transmission. The double helix ion funnel with an auxiliary electrode comprises two spiral electrodes, wherein the spiral electrodes have a constant inner diameter section and a conical inner diameter section connected to each other along the ion transmission direction, and four auxiliary electrodes are arranged at the outlet of the conical inner diameter section. The four auxiliary electrodes cooperate with the double helix electrode so that the positive / negative electrodes are arranged alternately, and a hexapole structure is formed at the outlet of the double helix ion funnel to improve the edge field. With the cooperation of the auxiliary electrode and the double helix electrode, the present invention greatly improves the influence of the edge field on the double helix electrode structure. The transmission efficiency of low and medium mass-to-charge ratio ions in the rough vacuum region is enhanced, and is almost unaffected by potential traps. At the same time, the ion strength is also enhanced, which helps to achieve a lower detection limit and higher sensitivity.

The present invention provides a tumor marker HE4 probe and a construction method and application thereof, belonging to the field of bioanalysis technology; in the present invention, a tumor marker HE4 probe is constructed, the probe is recorded as Fe3O4 / α-Fe2O3@Au-ssDNA / Apt / BSA magnetic nano HE4 aptamer probe, and the linear range of the detectable concentration of the probe is 0.1pg·mL ‑1 ‑1ng·mL ‑1 , the detection limit is 0.01pg·mL ‑1 , the limit of quantification was 125.3 fg·mL ‑1 ; The present invention also constructs an electrochemical nucleic acid sensor based on the probe, which has a good application in HE4.

The invention discloses a bionics and electrochemistry-based tea astringent flexible sensor and a detection device thereof. The detection method comprises four steps of preparation of an interdigital electrode, preparation of a pre-gel solution, ultraviolet polymerization of hydrogel and reading of an electric signal of the device. The preparation method of the interdigital electrode comprises the following steps: selecting a substrate film; cleaning the flexible substrate; manufacturing a flexible interdigital electrode; the astringent taste sensor prepared by the invention has excellent detection limit, sensitive reaction speed and high accuracy. When an astringent solution diffuses into a hydrogel matrix, entering astringent molecules are combined with mucoprotein to form hydrophobic molecules, so that the porous structure in the hydrogel is densified and porous, the ionic conductivity of the hydrogel is enhanced, and the astringent strength of the solution can be judged according to the change of the resistance of the sensor.

The application provides a method for determining ultra-low content thallium in iron ore, which adopts an extraction separation method to extract thallium from a multi-component test solution containing iron, calcium, aluminum and silicon, realizes separation and enrichment, and then determines by using an inductively coupled plasma emission spectrometer; the application utilizes the chemical properties of thallium and alkane compounds containing active oxygen substituents represented by 4-methyl-2-pentanone, adopts an extraction method for separation and enrichment, establishes a suitable analysis method, and completes the detection of ultra-low content thallium in ore.

The application discloses a kind of based on surface acoustic wave activation electrochemical microorganism device and method, the device includes electrolytic cell main body, working electrode, surface acoustic wave excitation module;The working electrode, attached electrochemical microorganism;The surface acoustic wave excitation module, by applying alternating signal generates surface acoustic wave, surface acoustic wave spreads to working electrode area, and acts on the electrochemical microorganism attached on working electrode.The method includes that reference electrode, working electrode, counter electrode are accessed electrochemical workstation;Start surface acoustic wave excitation module, and alternating signal is applied to the interdigital transducer in this surface acoustic wave excitation module, for generating Rayleigh wave;Through peristaltic pump, bacteria liquid is placed into device, and after flowing through working electrode, it is discharged to sterile container, and this step is recycled 3-5 times.