37results about How to "High sensitivity and selectivity" patented technology

This invention describes an ion mobility spectrometer system for chemical detection in the field. The system allows: a high throughput operation, an interface to new ionization methods, and an interface to a mass spectrometer.

This invention describes an ion mobility spectrometer and operational methods for chemical analysis. The ion mobility spectrometer allows for continuous operation and rapid temperature control to reach designed operational conditions, as well as analysis under a temperature gradient.

Methods and devices are provided for the detection of bacterial agents such agents as Bacillus anthracis and Clostridium botulinum with high sensitivity and selectivity. More specifically, methods and devices are based on a phosphorescence-emission detection system using chelate-stabilized lanthanides (e.g, Eu(III), Tb(III), and Sm(III)) to detect various spore-specific small organic molecules (e.g., dipicolinic acid, diaminopimelic acid, n-acetlymuramic acid, and the like). By careful selection of the chelating agent or ligand coordinated to the lanthanide, both high specificity and selectivity can be obtained. Examples of suitable and preferred sensor systems include N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) and N-(2-hydroxyethyl)iminodiacetic acid (HEIDA) combined with europium (III) and / or terbium (III). The chelate-stabilized lanthanides react with the spore-specific “target” molecules to form a characteristically phosphorescent product which can then be detected.

A composite metal oxide gas-sensing material with noble metal doped and its production are disclosed. The procedure is carried out by doping noble metal into ZnO-SnO2 to obtain metal composite oxide material Mo-ZnO-SnO2, and regulating compound composition, concentration of metal salt solution, Zn / Sn mol ratio, precipitation value and aging time. The metal composite oxide consists of noble metal 0.5-6mol%, its grain size distribution is 20-80nm and specific surface is 30-120m2 / g.

The invented electrochemistry sensor for measuring dopamine includes the glass-carbon electrode whose surface is coated with the sensing film composed of nano carbon tubes-Nafion of polymer of cation exchange. The Nafion of polymer of cation exchange is as the dispersant in the invention. The very stable nano carbon tubes can easily be dispersed in ethanol by the dispersant. The sensing film is prepared by coating the dispersant on the surface of the glass-carbon electrode. The dopamine is measured with high selectivity and sensitivity by using the electrochemistry sensor composed of the sensing film and the glass-carbon electrode. Even both of ascorbic acid and uric acid with high concentration are existed in the dopamine with low concentration, the electrochemistry snesor still gives the selective response.

This invention describes an ion mobility spectrometer system for chemical detection in the field. The system allows: a high throughput operation, an interface to new ionization methods, and an interface to a mass spectrometer.

The present invention relates to a compound which is a novel two-photon absorbing fluorescent substance, a production method for the compound, a fluorescence sensor and molecular probe able to sense various substrates or enzyme activity or the like using the same, and a method of sensing enzyme activity or the like using the same. More specifically, the present invention relates to a novel two-photon absorbing fluorescent substance which has the high photo-stability and large two-photon absorption cross-section value of acedan which is a two-photon absorbing fluorescent substance, and has the high fluorescence efficiency of coumarin which is a one-photon absorbing fluorescent substance, while exhibiting absorption and emission characteristics at a longer wavelength than existing acedan and coumarin and so being advantageous in in-vivo imaging. The compound according to the present invention can be used as a fluorescence sensor which is highly sensitive and selective for various substrates, and more particularly, can be used in the study and treatment of diseases in which MAO enzymes are involved such as mood disorders using MAO enzyme activity and inhibitor screening.

The invention relates to a glycosyl functional bacterial toxin molecularly imprinted membrane substrate as well as a preparation method and an application thereof. The molecularly imprinted membrane substrate forms a reaction layer on the surface of a gold quartz crystal substrate by taking a glycosyl functional bacterial toxin molecularly imprinted polymer as a recognition element. The preparation method comprises the following steps: selecting a carbohydrate molecule functional monomer which can carry out specificity recognition with bacterial toxin and compound the corresponding molecularly imprinted polymer; preparing a glycosyl functional molecularly imprinted polymer solution; and modifying the glycosyl functional molecularly imprinted polymer on the surface of the gold quartz crystal substrate by a substrate surface modifying technology to form a reaction layer. The glycosyl functional molecularly imprinted membrane substrate prepared by the method is connected to a piezoelectric quartz crystal microbalance to detect bacterial toxin in an environmental sample extracting solution. The molecularly imprinted membrane substrate has favorable molecular recognition performance and greatly improves the sensitivity and the selectivity for detecting the bacterial toxin.

The present invention relates to drift tubes for ion mobility spectrometers. In one embodiment, the drift tube of the present invention uses a simplified design having helical resistive material to form substantially constant electric fields that guide ion movements. The drift tube for ion mobility spectrometers described herein is constructed with a non-conductive structure. This configuration provides a robust ion mobility spectrometer that is simple to build. One feature of the present invention is that the drift tube design described herein enables the ion mobility spectrometer to be built with a lower weight, lower power consumption, lower manufacturing cost, and free of sealants.

The invention relates to a preparation method of an aluminum-titanium codoped ZnO-based acetone gas sensor. The preparation method is applicable to the field of preparation of gas sensor device with high selectivity characteristic on acetone steam. The preparation method comprises the following steps: preparing Zn(OH)2 sol by adopting a sol-gel method, quantitatively adding dopants, namely aluminum nitrate and hexadecyl trimethyl ammonium bromide, and additionally preparing Ti(OH)4 sol as a titanium doping agent; respectively drying, grinding and cleaning the two kinds of colloids, mixing thetitanium doping agent and Zn(OH)2 powder according to a molar ratio of aluminum to titanium of 1:(1-3), then annealing, mixing a powder material with hexadecyl trimethyl ammonium bromide, coating theceramic tube, and annealing again, so that a side heating type thick film gas-sensitive element is obtained; and ageing the element for 5-7 days. The preparation method provided by the invention is simple, the obtained element has good selectivity on acetone, and effective detection on trace amount of acetone is realized.

The invention discloses a method for determining contents of vitamin K1 and vitamin K2 in modified milk powder. The method comprises the following steps of: (1) extracting vitamin K1 and vitamin K2 inthe modified milk powder to be determined by adopting modes of enzymolysis and saponification to obtain a sample extracting solution; (2) detecting the vitamin K1 and the vitamin K2 in the sample extracting solution by adopting a post-column zinc powder reduction-high performance liquid chromatography-fluorescence detection method to obtain liquid chromatography data; and (3) according to the liquid chromatogram standard working curves of the vitamin K1 and the vitamin K2, obtaining the contents of the vitamin K1 and the vitamin K2 in the modified milk powder to be determined. The method is accurate in qualitative and quantitative analysis, high in sensitivity and good in reproducibility, and can meet the detection requirements of the vitamin K content in the modified milk powder.

The invention relates to a molecular imprinting electrochemical sensor for detecting trace bisphenol A. A glassy carbon electrode is modified with reduced graphene oxide doped with palladium (rGO@Pd), and electropolymerization is carried on the modified electrode by using pyrrole as a functional monomer and bisphenol A (BPA) as a template molecule to obtain the BPA molecular imprinting electrochemical sensor. When the BPA is within a concentration range of 1.0 nM to 10.0 nM, electrochemical signal rise level is in good linear relation with BPA concentration, and a process detection limit is 0.1 nM. The molecular imprinting electrochemical sensor for detecting trace bisphenol A overcomes the defects that the prior art methods for detecting BPA are complicated and the steps are difficult, detection sensitivity and selectivity are better improved, and it is easy to automate the detection of low-concentration BPA.

This invention relates to a near infrared fluorescent probe for detecting hydroxyl free radicals, synthesis method and use thereof. The near-IR fluorescent probe, manufacture method and application for -OH Free Radical --a. adding the 2, 2, 6, 6-tetramethyl peridol and strong base by mole ratio as 1:0.5~2.5 into the DMF to dissolve and water-bath react for 25-40min with IG protection; b. adding Cyanine-7 into the solution by same mole rate with the DMF to obtain the Cyanine-7 solution; adding former mixed liquid into the current solution slowly within 10-20min for reaction 25-35min in dried brash ice; c. vacuum evaporating the product to remove the DMF, cleaning with aether, and vacuum drying to obtain the coarse product; d. separating with silica gel column chromatography for the deep-blue solid pure product.

The invention discloses a functional optical fiber evanescent field sensor based on solid phase extraction and an assembly method of the functional optical fiber evanescent field sensor. The sensor comprises a light source, an optical fiber, a capillary tube, a photomultiplier tube detector and a liquid conveying unit, wherein an outer cladding layer on the surface at the left end of the optical fiber is retained, the outer cladding layer in the middle and at the right end are completely removed to expose the optical fiber core, the optical fiber core is inserted into the capillary tube and extends out of the capillary tube, both ends of a gap between the optical fiber core and the capillary tube are sealed, and a liquid flow cell is formed; a liquid inlet is formed in the left end side wall of the capillary tube, and a liquid outlet is formed in the right end side wall; an adsorption column is arranged on a liquid transport tube or an adsorption material layer is embedded in the surface of the optical fiber core in the flow cell, the light source is located on the left side of the optical fiber and coupled with the optical fiber, and a photomultiplier tube is arranged below the capillary tube to detect the change of evanescent field intensity. An analyte is pre-enriched on an adsorption material with a pre-enrichment technology, interference of a matrix is eliminated by the solid phase extraction, selectivity and sensitivity are also improved, and detection of the trace analyte is realized.

The invention relates to a sensitive material for detecting methyl alcohol gas and belongs to the technical field of gas sensors.The sensitive material is characterized by being compound powder, which is composed of 90-100% of SnO2, 1-3% of SiO2, 0.2-2% of PdC12, 0.2-2% of Sb2O3, 1-3% of Pt, 0.4-1.0% of V2O5 and 20-40% of In2O3.A preparation method of the sensitive material comprises the steps of synthesizing SnO2 nano microspheres through a one-step hydrothermal method, and then conducting solid phase synthesis on nano powder of SiO2, PdC12, Sb2O3, Pt, V2O5 and In2O3 and the prepared SnO2 nano microspheres.A methyl alcohol gas sensor made of the sensitive material has the advantages of being high in sensitivity, high in response speed, prominent in selectivity, good in stability, low in working temperature and the like, microscale methyl alcohol can be detected on line rapidly and accurately without being disturbed by common coexisting substances, and the sensitive material is a promising sensitive material for detecting the methyl alcohol gas.

The invention discloses a method for detecting trace hydroquinone by using a graphene / carbon nano tube modified electrode. The graphene / carbon nano tube modified electrode is a working electrode, and a method for detecting trace hydroquinone in water is established by means of different current catalytic strengths of the graphene / carbon nano tube modified electrode to hydroquinone with the concentration of respectively 0.6mu mol / L, 0.8mu mol / L, 2mu mol / L, 4mu mol / L, 6mu mol / L, 8mu mol / L, 20mu mol / L, 40mu mol / L and 60mu mol / L. The scanning potential is -0.2-0.6V, and the scanning speed is 100mV / s. In a 0.02mol / L phosphate buffered solution (PBS) with a pH value of 7.4, the concentration of the hydroquinone is within the range of 6*10<-7>-6*10<-5>mol / L, a favorable linear relation is formed between the concentration and the catalytic current strength on the surface of the electrode, and the detection limit is 2.13*10<-7>mol / L. The method is sensitive, good in selectivity, and more convenient and simpler in detection of low-concentration hydroquinone.

The present invention relates to a preconcentrator for vapors and particles collected from air. The vapor preconcentrator is made from plural layer of coils. The coil is made of resistance alloy. The pitch size of the coil is made to precisely trap / filter out certain size of the particles during preconcentration. Multiple coils could be made with different pitch sizes to achieve multiple step filtrations. When the sample flow enters the preconcentrator chamber, it passes through the coils. The particles of different sizes are trapped on different layer of coils. The vapor sample can be trapped on any coils when interacted with the coil surface. They could be trapped without any affinitive coating as the preconcentrator is at relatively low temperature. Different coils or different sections of the coil can be coated with different material to trap chemicals of different classes. During the desorption process, the coils are flash heated with controlled temperature ramping speed to evaporate the trapped chemicals.

The invention discloses an aza-naphthyl imide Cd<2+> probe molecule, a synthesis method therefor and an application of the aza-naphthyl imide Cd<2+> probe molecule and relates to Cd<2+> probe molecules and synthesis and application thereof. The aza-naphthyl imide Cd<2+> probe molecule is used for solving the technical problem that the Zn<2+> interference resistance of the existing Cd<2+> detecting molecule probes is relatively poor. The aza-naphthyl imide Cd<2+> probe molecule disclosed by the invention has a structural formula represented by a formula shown in the description. A preparation method comprises the steps: subjecting pyrano[3,4,5-de]quinolin-2,4,6(1H)-trione and alkylamine to a reaction in ethanol, and separating an intermediate I; subjecting the intermediate I to a reaction with phosphorus oxychloride, and separating an intermediate II; subjecting the intermediate II to a reaction with 2-amino benzylamine, and separating an intermediate III; subjecting the intermediate III to a reaction with 2-chloroacetyl chloride, and separating an intermediate IV; and finally subjecting the intermediate IV to a reaction with di(2-picolyl)amine, and separating the aza-naphthyl imide Cd<2+> probe molecule. The probe is applied to fluorescence-reinforced detection on Cd<2+> in solutions or cells.

The invention discloses a two-channel copper ion detection test paper and a production method thereof. The two-channel copper ion detection test paper comprises a color developing plate and a color developing substance on the color developing plate, and the color developing substance is a compound of formula I shown in the description. The copper ion detection test paper is simple to produce, thecolor developing substance simultaneously changes color and fluorescence obviously after meeting copper ions, and the signal changes of color matching and the fluorescence can be simultaneously observed with naked eyes and a portable ultraviolet lamp, so the selectivity and the sensitivity are higher than those of single colorimetry or single fluorescence methods. The two-channel copper ion detection test paper is especially suitable for onsite water quality analysis, and has the advantages of low cost, fast analysis speed, and accuracy in analysis.

The invention provides a method for detecting miRNA-155 by using an integrated paper-based dual-mode biosensor and belongs to the technical field of miRNA detection. According to the method of the invention, the integrated paper-based dual-mode biosensor is constructed; according to the integrated paper-based dual-mode biosensor, an S1@CuCo-CeO2 nano material is adopted as a signal amplifier and is used for the ultra-sensitive sensing of miRNA-155. In order to achieve the objective, firstly, CuCo-CeO2 nanospheres are synthesized to serve as signal probes, and then gold nanoparticles grow on the surface of a paper-based working electrode in situ so as to improve conductivity and promote the modification of miRNA-155 modified hairpin probes; through a hybridization chain reaction, the CuCo-CeO2 can be successfully fixed on the surface of the paper-based working electrode and is used for quantitatively detecting the miRNA-155; and dual-mode signal reading may be achieved by simply converting the spatial configuration of the paper-based biosensor.

The invention relates to a nano-sensitive material for monitoring a dichlorodiphenyltrichloroethane pesticide. The nano-sensitive material is characterized by consisting of Pd atom-doped La2O3, Fe2O3 and NiO nano-powder, wherein the Pd atom-doped La2O3, Fe2O3 and NiO nano-powder comprises the following components: 2 to 3 percent of Pd, 29 to 35 percent of La2O3, 38 to 44 percent of Fe2O3 and 18 to 24 percent of NiO; and the particle size range is 15 to 35nm. A dichlorodiphenyltrichloroethane pesticide sensor which is prepared from the sensitive material has a relatively wide linear range, is high in selectivity and relatively high in sensitivity, can monitor a trace amount of dichlorodiphenyltrichloroethane pesticide on line, and is not affected by coexisting substances.

The invention relates to a method for rapidly detecting amylose and amylopectin in highland barley. The method comprises the following steps: (1) preparing amylose and amylopectin standard solutions;(2) preparing amylose and amylopectin determination liquid; (3) determining measurement wavelengths and reference wavelengths of amylose and amylopectin through an equal-absorption dual-wavelength elimination method; (4) respectively measuring absorbance values of amylose and amylopectin measuring solutions at the measuring wavelength of 563 nm and the reference wavelength of 511 nm of amylose andat the measuring wavelength of 542 nm and the reference wavelength of 722 nm of amylopectin; 5, drawing a standard curve; (6) adding absolute ethyl alcohol into the highland barley powder, and performing whirling to wet the sample; (7) preparing a starch extracting solution; (8) preparing a starch determination solution; and (9) determining the absorbance value of the starch determination liquid,and then respectively searching the corresponding starch mass on the dual-wavelength amylose and amylopectin standard curves, so as to respectively calculate the content of amylose and amylopectin inhighland barley, and the sum of the content of amylose and amylopectin is the total starch content. The method is simple, accurate and high in efficiency.

A chromatogram mini type detector relates to mini type detector body, detector circuit and temperature control system. The mini type detector fixes with electric heating equipment, and the latter connects with detector circuit by temperature control system. The said mini type detector body joins a mini type detecting room by interface and the room settled with a gas educing hole. The said detecting room joins with one gas sensitivity sensor by sealed inset type interface and the said sensor connects with detector circuit. The mini type detector has trail huff interface and chromatogram columniation interface. The trail huff interface connects with surface blow parts of gas sensitivity sensor and connects with chromatogram columniation by its interface. Its configuration is integral, micromation, modularization and general-purpose property with excellent sensitivity and choice characteristic and favorable S / N and stability.

The invention discloses a molecularly imprinted electrochemical sensor based on a magnetic mesoporous titanium dioxide material as well as a preparation method and application of the molecularly imprinted electrochemical sensor, magnetic mesoporous titanium dioxide is taken as a carrier, surface modification is performed on the mesoporous carrier through a dopamine functionalized RAFT reagent, and finally, a magnetic mesoporous molecularly imprinted polymer can be obtained through RAFT polymerization. An electrochemical sensor with a specific recognition function on tetracycline can be constructed by modifying the magnetic mesoporous molecularly imprinted polymer on the surface of an electrode. According to the invention, a molecularly imprinted polymer layer is prepared through reversible addition-fragmentation chain transfer active free radical polymerization reaction initiated on the surface of a mesoporous titanium dioxide material; the prepared magnetic mesoporous molecularly imprinted polymer shows a regular spherical structure, is good in dispersity and has an obvious multi-layer core-shell structure; the electrochemical sensor disclosed by the invention shows a good selective recognition function on target molecule tetracycline in the presence of structural analogues, and has a wide application prospect in recognition and detection of tetracycline in food.

The present invention relates to ion mobility spectrometers. In one embodiment, the ion mobility spectrometer of the present invention uses a simplified ion mobility spectrometer design having helical resistive material to form substantially constant electric fields that guide ion movements. The drift tube for ion mobility spectrometers described herein is constructed with a non-conductive structure. This configuration provides a robust ion mobility spectrometer that is simple to build. One feature of the present invention is that the drift tube design described herein enables the ion mobility spectrometer to be built with a lower weight, lower power consumption, lower manufacturing cost, and free of sealants.

The invention discloses a reactive near-infrared photoactive receptor as well as a synthesis method and application thereof. The chemical structural formula is shown in the specification. An acyl thiourea bridge is accurately designed to combine silicon-rhodamine spirolactam and ferrocene into the reactive near-infrared photoactive receptor for the first time; 1,3,4-oxadiazole is generated througha specific desulfurization cyclization reaction of Hg<2+> ions to open the silicon-rhodamine spirolactam ring, selective efficient multi-mode detection of Hg<2+> ions in a water phase based on ultraviolet visible spectrum, fluorescence spectrum, colorimetric or electrochemical analysis and other technologies is achieved, and the lowest detection lower limit is 8.4*10<-9> M. The receptor providedby the invention is good in chemical and biological stability, has near-infrared color developing capability and fluorescence response characteristics, is wide in pH detection range (pH is 3.9-9.9), is particularly suitable for living cell fluorescence imaging, and has a wide application prospect.

The present invention relates to a preconcentrator for vapors and particles collected from air. The vapor preconcentrator is made from plural layer of coils. The coil is made of resistance alloy. The pitch size of the coil is made to precisely trap / filter out certain size of the particles during preconcentration. Multiple coils could be made with different pitch sizes to achieve multiple step filtrations. When the sample flow enters the preconcentrator chamber, it passes through the coils. The particles of different sizes are trapped on different layer of coils. The vapor sample can be trapped on any coils when interacted with the coil surface. They could be trapped without any affinitive coating as the preconcentrator is at relatively low temperature. Different coils or different sections of the coil can be coated with different material to trap chemicals of different classes. During the desorption process, the coils are flash heated with controlled temperature ramping speed to evaporate the trapped chemicals.

The present invention relates to a preconcentrator for vapors and particles collected from air. The vapor preconcentrator is made from plural layer of coils. The coil is made of resistance alloy. The pitch size of the coil is made to precisely trap / filter out certain size of the particles during preconcentration. Multiple coils could be made with different pitch sizes to achieve multiple step filtrations. When the sample flow enters the preconcentrator chamber, it passes through the coils. The particles of different sizes are trapped on different layer of coils. The vapor sample can be trapped on any coils when interacted with the coil surface. They could be trapped without any affinitive coating as the preconcentrator is at relatively low temperature. Different coils or different sections of the coil can be coated with different material to trap chemicals of different classes. During the desorption process, the coils are flash heated with controlled temperature ramping speed to evaporate the trapped chemicals. Various configurations, constructions, and methods of operation are presented.