47 results about "Fluorescence ratio" patented technology

The application discloses an aggregation-induced emission metal organic framework, a preparation method thereof and fluorescent / colorimetric dual-mode intelligent detection for trace HCl. 2+ The aggregation-induced emission metal organic framework is prepared by providing Zn(NO3)3.6H2O as Zn 2+ , imidazole-2-formaldehyde and an AIE molecule HDBB as organic ligands, and through a solvothermal method to obtain ZIF-90-HDBB, which can change the aggregation state fluorescence from yellow green to orange red after being contacted with HCl gas; the ZIF-90-HDBB is uniformly loaded on cellulose filter paper to obtain a paper-based sensor for portable detection of HCl, and through combination with a color recognition APP of a smart phone, the HCl can be rapidly and sensitively detected on site in a fluorescent / colorimetric dual mode. Since the HDBB molecule is prone to protonation under acidic conditions, the fluorescence color changes, and therefore the material can be accurately and efficiently used for detection of acidic gas, and the material can be recycled.

The invention discloses a double-emission carbon dot hydrogel film as well as a preparation method and application thereof, and relates to the technical field of analysis detection and functional materials. The double-emission carbon dot hydrogel film takes polyvinyl alcohol hydrogel as a carrier, and double-emission carbon dots (O-CDs) synthesized by taking L-glutamic acid and o-phenylenediamine as precursors are uniformly dispersed in the polyvinyl alcohol hydrogel. The O-CDs have double emission peaks of 400 nm and 530 nm under the excitation of 375 nm. The dual-emission carbon dot hydrogel film is applied to portable visual detection of Cu < 2 + > and Ag < + >, and the portable visual detection is dual-mode measurement based on RGB and comprises fluorescence colorimetric measurement in a solution and visual detection of the film assisted by a smart phone. According to the dual-mode strategy, precise instruments are not needed, rapid, reliable and synchronous detection of Cu < 2 + > and Ag < + > can be achieved within 10 min, the limitation of traditional single-mode detection is broken through, and a stable platform is provided for on-site metal ion monitoring.

The application provides a nucleic acid test strip and a detection method for detecting smut genes, and belongs to the technical field of detection. The application comprises a bottom plate, a sample pad and a water absorption pad; an NC film is attached to the bottom plate, the NC film is provided with a T line and a C line, the T line is sprayed with a coupling agent of a capture probe and streptavidin; the C line is sprayed with a coupling agent of a quality control probe and streptavidin; the quality control probe is complementary to a DNA sequence of a DNA1-AgInS2 / ZnS fluorescent probe. The application utilizes the advantages of AgInS2 / ZnS quantum dots (AgInS2 / ZnS QDs), such as good biocompatibility, high fluorescence intensity and wide spectral range. The test strip based on AgInS2 / ZnS quantum dots has higher sensitivity and stronger quantitative capacity than traditional test strips. The fluorescence ratio of the T line and the C line is detected by using a fluorescence immunoassay instrument for quantitative detection, the fluorescence immunoassay instrument can quickly read out the value, and has the advantages of rapidness, simple operation, low sensitivity, good selectivity and the like.

The application discloses a fluorescent colorimetric ionic liquid, a composite ionic probe and application in detection of phoxim, and the functionalized composite ionic probe is successfully synthesized by electrostatic self-assembly of the fluorescent colorimetric ionic liquid and a surfactant, the sensitivity and selectivity of the composite ionic probe in detection of phoxim are effectively improved, and the detection limit is reduced, and the detection limit of the fluorescent method in detection of phoxim can reach 3.0*10 ‑8 M, which is lower than the minimum maximum allowable concentration specified in the national standard. The composite ionic probe can visually and conveniently detect phoxim.

Systems and methods for multiplex detection through measurement of localized fluorescence ratios are disclosed herein. This can include creating a plurality of capture structures that each include a detection portion that can couple with a target analyte and a stem that can include a capture structure code uniquely identifying a type of the capture structure. The capture structures can be attached to a sample surface and mixed with a sample containing a plurality of target analytes. A location and the capture structure code of each of the capture structures can be determined. A location at which a target analyte is bound to one of the capture structures can be identified, and the target analyte can be determined based on the capture structure code of the capture structure at the location at which the target analyte is bound to one of the capture structures.

The invention relates to the technical field of fluorescence sensing and colorimetric detection, in particular to a concentration-gated three-emission fluorescence-colorimetric dual-mode visual sensing probe as well as a preparation method and application thereof. A three-emission fluorescence system is combined with a colorimetric signal, multiple reading channels are provided, the lower detection limit is remarkably lower than that of a traditional single-signal sensor, and good linear response is kept in a wide concentration range. Fluorescence and colorimetric modes are based on different mechanisms and are mutually independent and complemented, so that false positive / negative is effectively avoided, and the reliability of a detection result is remarkably improved. The continuous change of the fluorescence color from blue to red to orange to yellow to green can be identified by naked eyes or a smart phone, and the method is suitable for on-site rapid detection and semi-quantitative analysis. A concentration gating mechanism enables the sensor to present a switching type response behavior in a low / high concentration interval, a saturation phenomenon is avoided, a detection dynamic range is expanded, and the sensor is especially suitable for synchronous monitoring of trace and excessive residues of TC.

The invention discloses a fluorescent material with alpha-cyano diarylethene as a skeleton structure, a synthesis method and application of the fluorescent material in determination of the water content of an organic solvent. The chemical name of the fluorescent material is 2-hydroxy-1, 3-bis [2-(4-pyridine-4-yl phenyl) vinyl nitrile] benzene, the structural formula of the fluorescent material is shown in the specification, and the fluorescent material is prepared from self-made 2-(4-pyridine-4-yl phenyl) acetonitrile and m-hydroxyphthalaldehyde through a Knoevenagel condensation reaction. The fluorescent material has the characteristics of aggregation-induced fluorescence enhancement and adjustable fluorescence in the isomerization process. The fluorescent material can be used for performing fluorescence-colorimetric dual-mode high-sensitivity quantitative detection on the water content in the organic solvent, and the specific performance is as follows: within a certain range, along with the increase of the water content in the organic solvent, the maximum fluorescence emission peak and the maximum ultraviolet absorption peak of the fluorescent material present regular blue shift, and both have a good linear relationship. The fluorescent material is a novel fluorescent-colorimetric dual-mode sensor capable of performing high-sensitivity quantitative detection on the water content in an organic solvent.

This invention provides a method for constructing a donor-acceptor type perylene diimide-based porous conjugated polymer probe and detecting methamphetamine and amphetamine solutions. The method synthesizes donor-acceptor type perylene diimide-based porous conjugated polymer probes with different topologies by combining an electron acceptor perylene diimide derivative and an electron donor aggregation-induced emission fluorophore via a succinate coupling reaction. When used for the detection of methamphetamine and amphetamine, this system exhibits a clear ratiometric fluorescence response, with the fluorescence color gradually changing from yellow-green to orange and orange-red, demonstrating a significant ratiometric fluorescence response. It features fast response speed, high detection sensitivity, good selectivity, and no interference from other common structurally and property-similar substances, enabling the differentiation and identification of methamphetamine and amphetamine.

The application discloses a kind of enzyme-free, entropy-driven combination DNA-AgNCs detection microRNA-21 fluorescence ratio type biosensor.The analysis method is composed of two parts, the first part is the target cycle design without enzyme, L-DNA, S, Trigger chain is mixed and annealed to form stable three-strand DNA substrate in PB and CH3COONa hybridization buffer according to 1:1:1 molar ratio, when target exists, Trigger is released in the triggered entropy-driven cycle amplification system;The second part is the ratio fluorescence signal probe part, Y2-DNA or Y3-DNA is mixed in PB buffer according to DNA:AgNO3:NaBH4=1:6:6 molar ratio, obtain Y2-AgNCs and Y3-AgNCs.Y2-AgNCs, Y3-AgNCs and equal concentration Y1-DNA are mixed with equal volume, form Y type ratio fluorescence signal probe.When target microRNA-21 exists, trigger entropy-driven reaction to cause strand displacement and release Trigger chain, it is hybridized with Y1 chain in Y type structure, open Y type structure, Y2-AgNCs, Y3-AgNCs chain dimer separates, realize the controllable change of fluorescence emission from red fluorescence to yellow fluorescence, through the change of the ratio of two fluorescence intensities, realize the high sensitivity detection of target microRNA-21.

The invention provides a near-infrared NIR-II region fluorescence ratio probe based on tumor-associated neutrophil and application of the near-infrared NIR-II region fluorescence ratio probe. The nanoprobe is a rare earth doped down-conversion nanocrystal with a core-shell structure, the surface of the rare earth doped down-conversion nanocrystal is modified with a response unit and a targeting unit, and the response unit can release a fluorescence signal through enzymatic cleavage of neutrophil elastase; and the targeting unit is used for targeting a tumor microenvironment integrin receptor. The nanoprobe has high specificity and sensitivity, high anti-interference capability and self-calibration capability, can realize NIR-IIb region ratio imaging, provides a key basis for early curative effect judgment, achieves accurate individual stratification, fills the technical blank of cancer immunotherapy curative effect monitoring, and promotes the development of a tumor immune microenvironment molecular imaging technology.

This invention discloses a method for detecting copper ion concentration based on a hydrogel-coated PMPCF-MZI sensor and a fluorescence colorimetric dual-sensor. The detection device consists of a broadband light source, a single-mode optical fiber, a polarization controller, a flow cell, a PMPCF-MZI sensor, and a spectrometer. In the fiber optic detection path, light emitted from the broadband light source passes through the polarization controller and is input to the hydrogel-coated PMPCF-MZI, transforming into interference peaks of specific wavelengths. These peaks are displayed on the spectrometer. The hydrogel's volume and refractive index change after adsorbing copper ions, manifesting as a shift in the interference spectrum on the spectrometer. By comparing the relationship between different copper ion concentrations and the interference spectrum shift, rapid, accurate, and trace detection of copper ions in the aquatic environment is achieved. In the fluorescence detection path, the fluorescent detection solution is mixed with the test solution and irradiated with an ultraviolet lamp, inducing a change in fluorescence intensity, achieving visual qualitative detection. This invention employs a dual-system collaborative design, combining advantages such as simple structure, low detection limit, fast response time, easy operation, and high visualization. It has significant practical value and promising application prospects for rapid copper ion detection in the future.

The invention discloses a method for specific detection of sodium dichloroisocyanurate in ratiometric fluorescence-colorimetric dual modes, and belongs to the technical field of ratiometric fluorescence-colorimetric dual-mode sensors and sodium dichloroisocyanurate detection. The invention specifically constructs a sensor for specific detection of sodium dichloroisocyanurate in a ratio fluorescence-colorimetric dual mode, designs a method for specific and high-sensitivity detection of sodium dichloroisocyanurate in combination with ratio fluorescence and colorimetric, and can construct linear detection models at 4.0-40.0 [mu] mol / L and 2.0-70.0 [mu] mol / L respectively. And a novel and feasible method is provided for detection of sodium dichloroisocyanurate.

The invention discloses a nitrogen-doped carbon dot, a preparation method thereof and application of the nitrogen-doped carbon dot in pH detection and cell imaging, and provides an efficient strategy for preparing nitrogen-doped, in-situ passivated and amino-functionalized nitrogen-doped carbon dots through a one-step hydrothermal method based on the structural characteristics of a precursor. The prepared nitrogen-doped carbon dots have the excellent properties of high quantum yield, independent excitation, good stability, good biocompatibility and the like. Besides, rich amino groups introduced by diethylenetriamine enable the quantum dot to have good pH response property, fluorescence-colorimetric dual-mode detection within the pH range of 2.0-7.0 can be realized, and high-intensity emission can be maintained in strong base (pH is 14.0). Meanwhile, by means of halogen removal, the heavy atom effect is inhibited, the quantum yield is increased, the biotoxicity (dark toxicity and phototoxicity) of the compound is remarkably reduced, and the application of the compound in the field of biological imaging is expanded.

The invention belongs to the technical field of nano-enzyme preparation and sensing, and particularly relates to a laccase-like fluorescent nano-enzyme and application of the nano-enzyme in epinephrine dual-mode detection. The nano enzyme can realize the integration of the catalytic activity and the fluorescence property of imitated laccase in a single inorganic material, and can synchronously trigger obvious fluorescence signals and color changes in the same reaction system, so that the fluorescence-colorimetric dual-mode detection of epinephrine is realized. According to the technical scheme, the defects of poor stability and high cost of natural enzyme are avoided, the problems of tedious preparation steps, unstable performance and the like of the traditional composite fluorescent nano-enzyme are solved, meanwhile, the defects that single-mode detection is easily interfered by the environment and is insufficient in accuracy are overcome, and the method has the advantages of being simple and convenient to operate, high in sensitivity, good in accuracy and the like; the method can be used for various scenes from on-site rapid screening to laboratory accurate analysis and the like.

The invention relates to the technical field of metal organic framework materials, and particularly discloses a metal organic framework material for detecting glyphosate as well as a preparation method and application of the metal organic framework material. The prepared metal organic framework material is simple in raw material and simple and convenient to synthesize, glyphosate can be detected in a fluorescence-colorimetric dual mode, environmental interference caused by single fluorescence detection is avoided through complementary detection, the fluorescence mode detection limit of the metal organic framework material is 600 nM, the colorimetric mode detection limit of the metal organic framework material is 100 nM, and the detection requirement for trace glyphosate residues in agricultural products is met. The invention further provides a glyphosate detection means based on the paper-based sensor, the metal organic framework material is loaded on the surface of the paper-based sensor, after a sample is dropwise added, color or fluorescence changes can be observed for 15 min under natural light or an ultraviolet lamp, on-site preliminary rapid screening and judgment of glyphosate residues can be achieved without complex instruments, and the method is simple and convenient to operate. And the application scene of the technology is greatly expanded.

The invention discloses a multifunctional nano material fluorescence-colorimetric dual-mode food-borne pathogenic bacterium detection and killing method and a system thereof. According to the method, a metal organic framework material (MIL-53 (Fe)) with nano-enzyme activity is used as a signal switch and a generator, carbon nanodots (CDs) of a fluorescence indication and photo-thermal sterilization unit are combined to form a basic platform, and masking of an aptamer on a nano-enzyme active site and competitive release under triggering of target bacteria are used as a core mechanism. A colorimetric and ratiometric fluorescence double-signal channel is activated to realize self-verification high-precision detection; cDs in the system are used as a photo-thermal element, and in-situ photo-thermal sterilization is realized after detection. The platform design that detection objects can be switched by replacing the aptamers shows good universality and application prospects, and a sensitive and efficient new strategy is provided for detection and elimination of food-borne pathogenic bacteria.

The invention provides a fluorescence-colorimetric dual-mode lateral chromatography test strip platform and application, and belongs to the technical field of test strip detection. The fluorescence-colorimetric dual-mode lateral chromatography test strip platform comprises a fluorescent microsphere-gold nanoparticle conjugate and a DNA (Deoxyribose Nucleic Acid) signal amplification tree solution. The platform combines dual-mode detection of gold nanoparticles and fluorescent microspheres, can be observed by naked eyes, also can be used for quantitative analysis by a fluorescence analyzer, and has the characteristics of portability, low cost and high sensitivity. Meanwhile, the platform is a piece of lateral flow test paper based on a dendritic DNA signal amplification system, and can be used for rapidly and sensitively detecting pathogenic bacteria genes of the sugarcane pokkah boeng disease.

The invention discloses a membrane tension response type composite molecular sensor and a preparation method and application thereof, the membrane tension response type composite molecular sensor comprises a DNA tetrahedral framework formed by a plurality of single-stranded DNAs through complementary base pairing, and the single-stranded DNAs comprise single-stranded DNAs modified with vibration luminescent molecules, single-stranded DNAs modified with cholesterol molecules and unmodified single-stranded DNAs; the vibration luminescent molecule is loaded on the end point of one single-stranded DNA through covalent modification, and the cholesterol molecule is loaded on the end point of the other single-stranded DNA through covalent modification; the vibration light-emitting molecules are excited by single laser, switching between bending conformation and torsional conformation occurs, and then cell membrane tension is responded through emission wavelength intensity change. The membrane tension response type composite molecular sensor has the advantages of being controllable in size, high in brightness, high in cell membrane targeting performance and the like, fluorescence proportion imaging of cell membrane tension is achieved, and the huge potential of the membrane tension response type composite molecular sensor in research and application of the life process of stem cells is revealed.

The application discloses a kind of microbial multimode optical detection system and its application, including flow chamber, first detection light path, second detection light path and controller, through the control logic of screening, second detection light path trigger of first detection light path, second laser light source is only opened when detecting microorganism, avoid invalid excitation, make laser life prolong, reduce the optical damage of quartz flow chamber simultaneously.The "particle size+405nm fluorescence+280nm double-band fluorescence ratio" is created, which can effectively judge the survival state of bacteria and the inert particles adsorbing fluorescent substances, solving the industry problem of "inert particles adsorbing tryptophan being misjudged as dead bacteria" in the prior art.Using arc-shaped detector array to receive scattered light at multiple angles, combined with Mie scattering theory model, the particle size measurement accuracy of non-spherical microorganisms is significantly better than single-point detection scheme.The first detection light path and the second detection light path are spatially separated, and the scattered light and the fluorescent signal do not interfere with each other, so that the weak fluorescent signal of the small microorganism can be stably detected.

The invention discloses a preparation method of a diagnostic fluorescent probe adaptive to multiple detection. According to the method, a nano-carrier with a reactive functional group on the surface is used as a framework material, Alexa Fluor 488 and Alexa Fluor 568 are covalently constructed on the same nano-carrier to form a double-fluorescence ratio type coding structure, and biological recognition molecules are coupled in a modular manner, so that the diagnosis fluorescent probe capable of outputting a fluorescence intensity ratio signal is obtained. A ratio type signal interpretation mechanism is adopted, so that the influence of probe dosage fluctuation, exciting light drift and sample matrix difference on a detection result is effectively reduced; through stabilizing treatment such as surface passivation, colloid stabilization and biological activity protection, the dispersity and signal consistency of the fluorescent probe in the storage and use process are improved. The prepared fluorescent probe has good stability, universality and anti-interference capability, and is suitable for various in-vitro diagnosis application scenes such as immunoassay, flow cytometry and multi-channel imaging.

The present disclosure belongs to the field of fluorescent probes, and provides a fluorescent ratio probe and a development method and application thereof. The fluorescent ratio probe is 4-(4-dimethylaminostyryl) quinoline, referred to as QD, which is used for imaging and detection of beta-amyloid aggregates (referred to as Aβs) and monitoring of pH changes of the environment where the Aβs are located. The development method of the probe is also disclosed, and the application of the probe in preparation of a product for diagnosing the disease progression of Alzheimer's disease, which comprises the probe. The present disclosure provides a bifunctional fluorescent ratio probe QD which can light up Aβs and monitor the surrounding pH microenvironment, and has the characteristics of high affinity, good repeatability and simple operation. The QD has dual-color fluorescence when combined with Aβs, and the fluorescence ratio changes with the pH of the environment where the Aβs are located, so that the QD can be used to label Aβs in vivo and in vitro and display the pH microenvironment around the Aβs.

The application provides a kind of multi-photon action cross section measurement method and device, and the measurement method comprises: determining the target excitation mode type of the excitation wavelength to be measured;Wherein, excitation mode type includes any one of the following: three-photon excitation mode and four-photon excitation mode;Based on the target excitation mode type, the target action cross section value ratio formula is obtained;Wherein, the action cross section value ratio formula includes any one of the following: three-photon ratio formula and four-photon ratio formula;The reference excitation wavelength action cross section value of the same excitation mode type is input into the target action cross section value ratio formula, and the action cross section value of the excitation wavelength to be measured is calculated. Adopt fluorescence comparison method, and based on the known action cross section value of 1680nm excitation wavelength, the action cross section value of 2200nm excitation wavelength is obtained, the action cross section measurement of three-photon excitation mode and four-photon excitation mode of 2200nm window fluorescent marker is realized, so as to be able to characterize the multi-photon excitation at 2200nm.

The preparation method comprises the following steps: (1) taking citric acid and formamide as precursors, taking N, N-dimethylformamide (DMF) as an organic solvent, and obtaining DMF (Dimethyl Formamide) containing carbon quantum dots (CQDs) through a hydrothermal method; (2) taking ferric salt as a metal precursor, adding an organic ligand, taking the DMF containing the CQDs prepared in the step (1) as a solvent, and carrying out hydrothermal reaction to obtain Fe-MOF containing the CQDs, which is marked as MIL-53 (Fe)-CQDs; and (3) dispersing the MIL-53 (Fe)-CQDs prepared in the step (2) in a ternary system consisting of water, ethanol and ammonia water, adding tetraethoxysilane (TEOS), and stirring at room temperature to obtain the novel fluorescent nano enzyme MIL-53 (Fe)-CQDs (at) SiO2. The feasible and effective fluorescence-colorimetric dual-mode fluorine ion detection method is established, the detection range is large, the detection limit is low, the detection accuracy is remarkably improved through the application of the two analysis modes, and the detection requirements of fluorine ions in various water samples can be met.

This invention discloses a quantum dot fluorescent immunochromatographic quantitative detection method and kit for urinary NMP22, belonging to the field of in vitro diagnostic technology in biomedicine. This invention uses quantum dot fluorescent microspheres as markers and prepares NMP22 monoclonal antibody conjugates using the EDC / NHS activation method. An immunochromatographic test strip composed of a sample pad, a conjugation pad, a nitrocellulose membrane, and an absorbent pad is constructed. Based on the principle of a double-antibody sandwich immunoreaction, a quantitative standard curve is established using the T / C fluorescence ratio method to achieve accurate quantitative detection of NMP22 in urine. This invention optimizes the chromatographic system parameters for the characteristics of the urinary matrix, resulting in excellent detection sensitivity and specificity. The operation is simple, with results obtained in 15 minutes. No large-scale testing equipment is required, enabling real-time single-sample testing. It is suitable for early auxiliary diagnosis and postoperative recurrence monitoring of bladder cancer, with low testing cost, facilitating its widespread application in primary healthcare institutions.

The application belongs to the field of intelligent indication packaging of food, and particularly relates to a preparation method and application of a fluorescent ratio type meat freshness indication film. The application synthesizes double-emission carbon quantum dots through a one-step hydrothermal method, and then fixes the carbon quantum dots in a hydrophobic polymer film through an electrospinning method to prepare a portable indication label with high stability; the indication label responds to volatile biogenic amines, and can further monitor the freshness of chilled meat. The electrospinning film forming technology of the application obtains nanoscale fibers, which have a larger specific surface area and higher porosity than traditional films, and can uniformly fix the carbon dots in the fibers, and are more sensitive to gas; and the operation method and process are simple, the raw material cost is low, the raw material is easy to obtain and easy to realize industrialized production, and the application prospect is wide.

The utility model discloses a diabetes mellitus multi-index monitoring kit. Multiple indexes comprise three indexes of HBA1C, INS and ADPN. The kit comprises a blood taking needle, a diluent and a reagent card, the reagent card comprises a shell and a test strip, and the shell is provided with a time indicating device used for indicating reaction time and fluorescent colorimetric scales used for colorimetric detection of a detection fluorescence value obtained by the test strip so as to perform semi-quantitative detection on a detection result. The time indicating device reacts to change color when the diluent is added, the reaction is finished when the color is changed, the fluorescent colorimetric scales comprise a plurality of fluorescent sections with different intensities which are sequentially arranged along the same straight line, and the fluorescent sections with different intensities can display fluorescence with different brightness under the irradiation of an ultraviolet lamp. Colorimetric scales are arranged, so that visual semi-quantitative interpretation is supported; the kit has a time indication function, and when the color of the time indication changes, the reading can be carried out when the reaction is completed, so that constant-temperature incubation is not needed, and an accurate result can be obtained under the conventional room-temperature reaction.

The application discloses a kind of double-emission carbon dot hydrogel film and its preparation method and application, it is related to analysis detection and functional material technical field.The double-emission carbon dot hydrogel film with polyvinyl alcohol hydrogel as carrier, wherein uniformly dispersed with the double-emission carbon dot (O-CDs) synthesized with L-glutamic acid and o-phenylenediamine as precursor.O-CDs has dual emission peak of 400 nm and 530 nm under 375 nm excitation.Double-emission carbon dot hydrogel film is applied in Cu 2+ And Ag + Portable visual detection, which is a dual-mode measurement based on RGB, including fluorescence colorimetric assay in solution and smartphone-assisted visual detection film.The dual-mode strategy does not require sophisticated instruments, and can achieve rapid, reliable and simultaneous detection of Cu 2+ And Ag + Within 10 min, breaking through the limitations of traditional single-mode detection, and providing a robust platform for on-site metal ion monitoring.