415 results about "Quenching (fluorescence)" patented technology

The invention belongs to the technical field of biology, and discloses a stable protective agent, a cell antigen dry sheet and a preparation method and application of the dry sheet, the stable protective agent comprises glycerin with the volume fraction being 0.4%, gelatin with the mass volume fraction being 0.1%, EDTA with the mass volume fraction being 0.1 mM, trehalose with the mass volume fraction being 0.03% and resveratrol with the mass volume fraction being 100 [mu] M. The stable protective agent is adopted for preparing the cell antigen dry sheet, and the cell antigen dry sheet is applied to CBA detection. The stable protective agent has good permeability, can penetrate through cell membranes to enter cells, provides a protection effect inside and outside the cells, has moisture retention and oxidation resistance, can prevent cell deformation and cell fixing layer shedding, and can well maintain the stability and reliability of antigen proteins, and the prepared cell antigen dry sheet can be stored for a long time, and has a good application prospect. The antigenicity of a membrane signal index is not damaged. When a positive sample is detected, obvious green fluorescence cells can be seen, red fluorescence quenching is avoided, and co-localization of red fluorescence and green fluorescence can be observed conveniently.

The invention discloses a near-infrared two-region activatable probe as well as a preparation method and application thereof. The near-infrared second-region activatable probe comprises a near-infrared second-region fluorescent light-emitting unit and an analyte specific response unit; the near-infrared second-region light-emitting unit comprises a hemicyanine fluorophore structure; when the analyte specific response unit is chemically coupled with the near-infrared second-region light-emitting unit, the intramolecular charge transfer process of the light-emitting unit can be inhibited, and fluorescence quenching is caused; the analyte specific response unit is separated from the light-emitting unit after being subjected to specific reaction with an analyte, so that fluorescence is activated. The near-infrared two-region hemicyanine fluorophore selected by the near-infrared two-region activatable probe has higher fluorescence quantum efficiency, and the near-infrared two-region probe which can be activated by a specific analyte and has a high on-off ratio can be constructed by introducing an analyte specific response unit, so that high-temporal-spatial-resolution fluorescence detection of deep tissues can be realized; the method has a wide application prospect in the field of biomedical detection.

The invention belongs to the technical field of battery health state monitoring, and relates to an unmanned aerial vehicle battery health state on-line prediction method comprising the following steps: exciting a quantum dot tracer agent in a battery monitoring area to obtain an initial fluorescence spectrum, and carrying out real-time comparison to identify fluorescence quenching caused by gas production and generate a preliminary aging signal; further analyzing the spectrum drift characteristics so as to analyze lithium aging and pure gas production; triggering ultrasonic detection based on a diagnosis result, and extracting time-frequency characteristics of acoustic echoes to construct quantitative acoustic fingerprints; and finally, through cross validation of optical and acoustic information, generating a comprehensive health status report containing a risk level and an aging type. According to the method, multi-dimensional on-line diagnosis and early warning on the early aging stage of the battery are realized, and the problems of hysteresis quality, difficulty in positioning and inaccurate risk assessment caused by dependence on macroscopic electrical parameters in a traditional method are solved.

The invention relates to the technical field of fluorescent hydrogel, in particular to high-strength and high-stability fluorescent hydrogel as well as a preparation method and application thereof, the fluorescent hydrogel is formed by physical crosslinking of a hydrogel matrix, a rare earth fluorescent complex and a stabilizer, the hydrogel matrix is of a double-network structure formed by physical crosslinking of polyvinyl alcohol and carboxymethyl cellulose; the rare earth fluorescent complex is formed by connecting rare earth metal ions and an organic antenna material through coordination; the stabilizer is trisodium citrate. Compared with other fluorescent hydrogel, the fluorescent hydrogel with high strength and high stability provided by the invention has the advantages that the phenomena of fluorescence decay and fluorescence quenching caused by metal ions and saturated salt solution are avoided, and the fluorescence is kept stable in a wide pH range. Because the fluorescence characteristic is not influenced by environmental corrosion factors, the information can be stably displayed for a long time, and the method can be used for information encryption and anti-counterfeiting in an extreme environment.

The invention provides a preparation method of nitrogen and phosphorus-doped carbon dots and application of the nitrogen and phosphorus-doped carbon dots in quercetin detection, the nitrogen and phosphorus-doped fluorescent carbon dots (N, P-CDs) are successfully constructed for the first time by adopting a hydrothermal synthesis method, and the carbon dots have emission peaks at 465 nm under the excitation wavelength of 325 nm and show green fluorescence under the irradiation of an ultraviolet lamp; quinine sulfate is used as a standard reference substance, and the quantum yield is 1301%; an N, P-CDs solution is used as a probe molecule, after quercetin is added, fluorescence quenching of N, P-CDs is induced, and the concentration of quercetin and the fluorescence intensity of N, P-CDs are linearly changed, so that the method can be used for quantitative detection of quercetin. The N, P-CDs preparation method provided by the invention is simple and rapid, the product property is stable and non-toxic, the detection sensitivity on the quercetin is high, and the N, P-CDs can be used for detecting the content of the quercetin in serum.

The invention discloses a sensing material for detecting atmospheric carboxylic acid, a preparation method, a detection method and application, belongs to the technical field of environmental functional materials, and solves the problems that an existing method is complex in operation and cannot realize real-time online monitoring, the sensing material for detecting atmospheric carboxylic acid is an MOF-802-EDTA-Pt composite film, and the preparation method comprises the following steps: taking 1, 3, 4, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5- The preparation method comprises the following steps: synthesizing an MOF-802 material through a hydrothermal reaction by taking 1, 3, 5-benzene tricarbonic acid (BTC) and aluminum nitrate as raw materials and ethylene diamine tetraacetic acid (Na-EDTA) as a ligand; the preparation method comprises the following steps: dispersing MOF-802 in DMF to form a coating solution, and forming a film on a glass substrate through a pulling method; and then loading platinum nanoparticles, and carrying out solvothermal reaction and vacuum drying to obtain the composite sensing film. The MOF-802-EDTA-Pt composite film has a porous structure and fluorescence characteristics, and detection is realized through a fluorescence quenching effect of carboxylic acid molecules and an MOF skeleton. The method disclosed by the invention is controllable in process and high in material stability, still keeps excellent selectivity under the coexistence condition of interferents such as CO2 and NO2, and is suitable for real-time monitoring of carboxylic acid pollutants in the atmospheric environment.

The invention discloses a DNA silver nanocluster and a preparation method and application thereof, and belongs to the technical field of analytical chemistry. The method comprises the following steps: adding a template containing a DNA sequence and an AgNO3 solution into a PBS (Phosphate Buffer Solution), mixing, and carrying out a first dark reaction; then, adding a NaBH4 solution, and carrying out a second light-shielding reaction, so as to obtain the DNA-Ag NCs fluorescent probe; the DNA silver nano-cluster is applied to the determination of the cationic surface active agent; the fluorescence quenching effect is remarkable, the lowest detection limit can reach 2.0 mu M, the selectivity is good, common anionic surfactants, nonionic surfactants, metal ions in sewage and other interferents do not affect detection, and the accuracy and reliability of the method are improved.

The invention belongs to the technical field of fluorescent probes, and discloses a fluorescent probe based on BODIPY targeted lipid droplets and application of the fluorescent probe. The structural formula of the fluorescent probe for targeting the lipid droplets is as follows: # imgabs0 # is as follows: due to strong electron withdrawing capability and relatively large steric hindrance of ester groups, the ester groups of the probe can rotate in an excited state, so that energy is lost through non-radiative transition, and fluorescence quenching is caused. The ester group of the probe can rotate in an excited state due to the strong electron withdrawing capability and large steric hindrance of the ester group, so that energy is lost through non-radiative transition, and fluorescence quenching is caused. And due to the introduction of the ester group, the fat solubility of the BODIPY dye is further enhanced, so that the lipid droplet targeting property of the probe is effectively improved, and no-wash imaging of lipid droplets is realized.

The invention provides a method for specifically detecting AFP based on a photoinduced electron transfer effect between blood orange RCDots and an AFP-aptamer, and the preparation and AFP detection principles of a near-infrared PET fluorescent probe for AFP detection are as follows: the RCDots with rich carboxyl groups on the surface can strongly adsorb ssDNA to the surface of the RCDots through pi-pi stacking interaction; and a formed RCDots / AFP-aptamer compound is subjected to a photo-induced electron transfer effect, so that the fluorescence of the RCDots is remarkably quenched. However, the affinity between the AFP and the AFP-aptamer is stronger than pi-pi stacking interaction, so that ssDNA is separated from the surface of the RCDots, the light-induced electron transfer effect disappears, the fluorescence of the RCDots is recovered, and the fluorescence intensity is changed along with the change of the concentration of the AFP, so that the concentration of the AFP is detected with one kind of specificity. The detection method is simple, has the characteristics of wide detection linear range, low detection limit, good specificity and the like, and can be widely applied to clinical detection of liver cancer markers.

The invention discloses a method for evaluating the environmental risk of perfluorooctane sulfonic acid by using euglena gracilis, and belongs to the field of environmental pollutant biological monitoring and ecotoxicology evaluation. The method comprises the following steps: detecting the photosynthetic activity and the movement ability of Euglena gracilis exposed to perfluorooctane sulfonic acid with environmental concentration and the organelle distribution condition of the perfluorooctane sulfonic acid in euglena gracilis cells in situ; the photosynthetic activity comprises in-situ monitoring of chlorophyll fluorescence parameters and maximum non-photochemical quenching coefficient of euglena gracilis, and quantitative analysis of chloroplast pigment content; the movement ability comprises horizontal light-driving movement speed and vertical light-driving movement speed measurement of the euglena gracilis and flagellum shedding rate calculation. The method breaks through the limitation of a traditional single autotrophic mode, reveals a regulation and control mechanism of nutritional conditions on toxic effects, provides a scientific basis for water environment safety monitoring and optimization, and has the advantages of being convenient to operate and low in cost.

The invention discloses a fluorescent dye for shoe soles as well as a preparation method and application of the fluorescent dye, and belongs to the technical field of fluorescent materials for shoes. The fluorescent dye has a structure as shown in a formula 1. The preparation method comprises the following steps: synthesizing an intermediate through Buchwald-Hartwisting arylation reaction, and carrying out Suzuki coupling to obtain a target product. The dye inhibits aggregation fluorescence quenching through a rigid plane structure and a deuterated group, the HOMO-LUMO energy gap is regulated to 2.8-3.2 eV, the dye has the broad band emission of 450-600 nm, and the fluorescence quantum efficiency reaches 0.55-0.75. When the brominated butyl rubber is applied to a sole formula, the brominated butyl rubber comprises the following components in parts by weight: 40-60 parts of brominated butyl rubber, 0.1-2 parts of fluorescent dye and the like, and a finished product is prepared by mixing, vulcanizing and foaming. Compared with a traditional dye, the fluorescence intensity is improved, the photooxidation resistance is enhanced, the dissolution rate is reduced by 60% or above, and the dye has excellent humidity and heat resistance and material compatibility.

The invention relates to the field of viscosity detection, and provides a fluorescent probe for detecting the viscosity of mask essence as well as a preparation method and application of the fluorescent probe. 4, 4 '-(iminomethylene) bis (N, N-dimethylaniline) which is slightly soluble in water reacts with acid to form auramine hydrochloride, the water solubility of the auramine hydrochloride fluorescent probe is greatly enhanced, the probe in a water phase is converted into heat (non-radiation decay) due to twisted intramolecular charge transfer and excited state energy caused by benzene ring rotation, and fluorescence quenching is shown; when the viscosity of the solvent is increased, rotation of the benzene ring is blocked, excited state energy cannot be converted into heat and is dissipated in a radiation attenuation mode, fluorescence is enhanced, and viscosity detection of the mask essence with the main component being water is achieved based on the principle. According to the present invention, the method has characteristics of simple synthesis, stable property, no interference of solvent polarity during detection, long-term storage and long-term use, rapid and high-specificity viscosity response ability, and quantitative analysis of viscosity.

Provided is a temperature-responsive fluorescent particle comprising at least one type of fluorescent molecule in a molecular assembly comprising and constituted by at least one type of amphiphilic molecule, wherein the fluorescent molecule emits fluorescence when the molecular assembly is in the liquid phase and it is quenched when the molecular assembly is in the solid phase, due to a temperature-responsive solid-liquid phase transition, so that fluorescence emission and quenching of the fluorescent molecule are reversibly switched in a temperature responsive manner. Also provided is a temperature-responsive fluorescent probe comprising the temperature-responsive fluorescent particle the surface of which is modified with a biomolecule recognition element, and methods for detecting and quantitatively determining a biomolecule with the temperature-responsive fluorescent probe.

A method for manufacturing display panel including: forming pixel defining layer on one side of base substrate; forming quantum dot layer, including sequentially forming first quantum dot pattern of at least two quantum dot patterns, forming first quantum dot pattern of one quantum dot pattern including forming quantum dot film capable of emitting light with corresponding colors, quantum dot film including quantum dot body and cross-linkable ligand; performing local cross-linking process on quantum dot film; performing developing process on quantum dot film subjected to local crosslinking process to form first quantum dot pattern in pixel accommodating hole corresponding to corresponding color; after forming first quantum dot pattern of quantum dot patterns, the method includes performing fluorescence property quenching process to quench fluorescence of quantum dot body in quantum dot on surface of first quantum dot pattern and not subjected to crosslinking process. Also provided is display panel and display device.

The invention belongs to the technical field of pharmaceutical preparations, and particularly relates to a fluorescent carbon dot based on p-phenylenediamine and triphenylamine as well as a preparation method and application of the fluorescent carbon dot. The fluorescent carbon dots are obtained by taking triphenylamine and p-phenylenediamine as raw materials through a solvothermal method. The invention provides a functionalized carbon dot based on p-phenylenediamine and triphenylamine. The functionalized carbon dot can achieve 599 nm emission under excitation of the wavelength of 365 nm. NADH and active sites on the surfaces of the carbon dots form a non-fluorescent ground state compound through a static quenching mechanism, 599 nm fluorescence quenching and 444 nm emission enhancement are caused, and ratio fluorescence detection of NADH is achieved. The method is good in linear relation, high in selectivity, rapid in response and high in sensitivity, and the detection limit is as low as 108 nM.

The invention belongs to the technical field of talc, and provides a method for detecting fluorescent substances in talc raw ore, which comprises the following steps: S1, carrying out ball milling on the talc raw ore in a ball mill, sieving to obtain sieved powder, and adding deionized water into the sieved powder to obtain slurry; s2, adding the slurry into the mixture to enable the pH value of the slurry to be 5, stirring, and standing in a water bath for 2-3 hours to obtain a first precipitate; s3, adding a thiourea-ascorbic acid solution into the first precipitate to obtain a second precipitate; and S4, carrying out secondary ball milling on the second precipitate, and spreading the second precipitate in an enamel plate to detect whether the talc raw ore contains the fluorescent substances or not. The hydrochloric acid can dissolve quartz and mica to avoid generation of background fluorescence or quenching effect, and the nonionic surfactant polyethylene glycol can be adsorbed on the surface of the mineral to reduce interfacial tension, so that the hydrochloric acid is easier to infiltrate tiny pores, the pit defect caused by local over-corrosion is reduced, the pickling uniformity is improved, and the detection sensitivity is improved.

The invention relates to an automatic fluorescence quenching system and method. A sample storage unit is arranged on a rack. And the reaction quenching unit is arranged on the rack and is positioned on one side of the sample storage unit. The carrying unit is arranged on the rack, and the moving range covers the sample storage unit and the reaction quenching unit. And the sample reinspection unit is arranged on the rack and is positioned on the other side of the reaction quenching unit. And the sample recovery unit is arranged on the rack and is used for storing the biological samples which are qualified in quenching. The reagent unit is arranged in the rack and is connected with the quenching box of the reaction quenching unit through a liquid pipeline. The controller is in communication connection with the sample storage unit, the reaction quenching unit, the carrying unit, the sample reinspection unit, the reagent unit and the sample recovery unit. According to the automatic fluorescence quenching system and method, the problems of subjectivity and inconsistency due to the fact that a traditional method depends on manual observation and judgment are solved, the quenching effect of output samples is more stable, and the requirement for result consistency in high-throughput research is met.

The invention discloses application of a dual-emission Eu < 3 + > and Cd-MOF material in detection of polluting anions. Experimental results show that the material has an obvious fluorescence quenching effect on CrO4 < 2-> and Cr2O7 < 2->. When the amount of the added CrO4 < 2-> is 2.0 [mu] mol, the fluorescence intensity of the Eu < 3 + > Cd-MOF is quenched to 93.15% (500 nm) and 94.51% (620 nm); similarly, when the addition amount of Cr2O7 < 2-> is 2.0 umol, the fluorescence intensity of the fluorescent powder is quenched to 86.25% (500 nm) and 83.31% (620 nm). Therefore, the dual-emission Eu < 3 + > and Cd-MOF can selectively identify CrO4 < 2-> and Cr2O7 < 2-> ions, and has the advantages of rapidness, simplicity, convenience, sensitivity, accuracy and the like.

The application belongs to the technical field of fluorescent probe detection, and discloses a bimetallic nanocluster fluorescent probe compound and application thereof in preparation of a product for rapidly detecting acetylene. The fluorescent probe compound is a gold-copper bimetallic nanocluster solution modified by adamantane thiol, which is used as a fluorescent probe for acetylene detection. The solution has a clear and controllable preparation process. Through specific proportioning and reaction conditions of cuprous chloride, adamantane thiol, tetrachloroauric acid, sodium borohydride and other reagents, a probe solution with stable fluorescence characteristics can be prepared. The bimetallic nanocluster fluorescent probe compound is applied in preparation of a product for rapidly detecting acetylene. Through specific combination of fluorescent molecules and acetylene gas to trigger the secondary effect of fluorescence quenching, detection is realized, and other substances cannot trigger quenching. At a wavelength of 700 nm, the linear relationship (R 2 >0.99) between the fluorescence intensity and the acetylene concentration realizes accurate quantification of the acetylene concentration, and the minimum detection limit is 0.026 muL / L.

The invention discloses an amide chain-bridged bis-tetraphenylethylene fluorescent probe and a synthesis method and application thereof, belonging to the technical field of organic synthesis and analytical chemistry. The fluorescent probe has a structure of an oxalamide-bridged bis-tetraphenylethylene unit and is chemically named 1,2-bis(2-(4-(1-phenyl-2,2-di-dodecylphenyl)vinyl)phenoxyacetyl)ethylenediamine, i.e., Bis-TPE. In the invention, 1,1-di-p-dodecyloxyphenyl-2-phenyl-2-p-hydroxyphenylethylene, 1,2-bis-chloroacetylethylenediamine, and anhydrous potassium carbonate are selected as synthetic raw materials, placed in a dry acetone system for reflux, and after sufficient reaction, the reaction mixture is extracted and distilled under reduced pressure, and the product is separated by silica gel column chromatography, thereby synthesizing the fluorescent probe. The fluorescence intensity of the fluorescent probe of the invention is 1000 nm in Hg 2+ The quenching is obvious in the presence of , and the presence of other ions has little interference with the detection results. The rapid weakening of the fluorescence intensity of the fluorescent probe can be used to detect Hg in the solution. 2+ Highly efficient and selective detection.

The present invention provides a method for detecting ClO by fluorescence and ultraviolet. ‑ When the anion ClO is added to the pure aqueous solution of PY, ‑ , AcO ‑ ,H2AsO4 ‑ ,Br ‑ ,F ‑ ,Cl ‑ ,ClO4 ‑ ,CN ‑ ,H2PO4 ‑ ,HSO4 ‑ ,N3 ‑ ,NO3 ‑ ,NO2 ‑ ,OH ‑ ,SCN ‑ ,P2O7 2‑ When ClO ‑ It will cause significant quenching of the fluorescence emission spectrum and red shift of the UV absorption spectrum. However, the addition of other anions has no effect on the fluorescence and UV absorption of the phenazine derivative PY solution. It also shows good selectivity and anti-interference ability. At the same time, through fluorescence and UV titration experiments, it was found that ClO ‑ There is a good linear relationship between the concentration and fluorescence intensity, and the minimum fluorescence detection limit is calculated to be 5.59×10 ‑8 The minimum detection limit of M and UV is 5.84×10 ‑7 M. Finally, we made it into a test strip for semi-quantitative detection of ClO ‑ This recognition and detection performance has important application value in the field of ion recognition.

The application belongs to the field of explosive detection, and discloses a polyimide loaded triaminophthalocyanine probe, a preparation method thereof and application thereof in detecting nitroaromatic explosives. The probe has the following general structure formula. The probe is prepared by cross-linking copolymerization of 5,10,15-tri(4-aminophenyl)-20-phenyl porphyrin, aromatic tetracid dianhydride and aromatic organic diamine. The polyimide high-molecular cross-linked branch loaded triaminophthalocyanine compound with fluorescent light emitting performance is prepared for the first time. The probe is applied to detecting various nitroaromatic explosives by quenching fluorescence response, and the detection method is simple, and has good application prospect in the field of public security.

The invention discloses a TADF luminescent material and a preparation method thereof, and relates to the technical field of organic optoelectronics, the molecular structure of the material comprises a phenyl triazine derivative electron-deficient core as an electron acceptor and a carbazole or tert-butyl carbazole electron-rich group as an electron donor; an aggregation-induced emission mechanism is introduced into the thermally activated delayed fluorescence material, so that the aggregation-induced quenching problem of a traditional thermally activated delayed fluorescence material and the exciton annihilation effect under high brightness are effectively solved, and meanwhile, the defect that a traditional aggregation-induced emission molecule is low in electroluminescence efficiency is overcome; the material can be used for preparing a non-doped organic electroluminescent device, the process is simplified, the cost is reduced, and the material has application potential in the field of intelligent response materials.

The invention discloses an application of a copper nano-cluster with stable ascorbic acid in detection of p-nitrophenol, the copper nano-cluster with stable ascorbic acid is used as a fluorescent probe, and the detection of p-nitrophenol is realized through a fluorescent sensing method. Due to the quenching effect of p-NP, the fluorescence intensity of the system is obviously reduced in the presence of p-NP. The p-NP concentration can be quantitatively detected by comparing the fluorescence intensity of the copper nano-cluster and the fluorescence intensity of a quenching system. The method is simple, sensitive and high in selectivity, does not need complex fluorescent dye labeling, shows remarkable potential for p-NP detection, and has a good application prospect in the aspects of food, medicine and the like.

This invention provides a fluorescent labeling and conjugation method that exhibits enhanced signal intensity. [Solution] This disclosure relates to the field of fluorescent dyes, and more particularly to compositions and methods for increasing fluorescence signals and decreasing fluorescence quenching.

The invention relates to the technical field of smart agriculture, and discloses a spectrum feed-forward greenhouse control system based on physiological vector Pareto optimization, comprising an intelligent sensing module for collecting crop pulse modulation fluorescence parameters, spectrum fingerprints and environmental parameters; the model decision-making module is coupled with the three algorithm units, the long-period unit is used for outputting an optimal allowable interval of environment regulation and control based on a crop model, the short-period unit is used for predicting physiological risks and outputting dynamic regulation weights based on spectral feedforward, and the real-time unit is used for constructing physiological vectors composed of actual photochemical quantum yield and non-photochemical quenching; executing Pareto optimization under interval constraint and weight guidance, balancing light energy utilization efficiency and physiological stress, and generating an accurate control instruction; the intelligent execution module regulates and controls the environment; and the online calibration module is used for recording data to update the crop model and the prediction model online. According to the method, long-term energy efficiency planning and instantaneous physiological optimization are coordinated, and the precision, prospect and adaptive capacity of greenhouse control are improved.

The invention belongs to the technical field of chrysin detection, and particularly relates to a dual-emission fluorescent molecularly imprinted polymer as well as a preparation method and application thereof. The method comprises the following steps: preparing carbon dots with different emission wavelengths; carrying out amination modification on the carbon dots; and preparing the dual-emission fluorescent molecularly imprinted polymer. The method also comprises the following steps: respectively adding the dual-emission fluorescent molecularly imprinted polymer into chrysin solutions with different known concentrations, carrying out fluorescence quenching reaction, and establishing a standard curve according to the linear relationship between the detected fluorescence intensity and the corresponding concentration of the chrysin solution; adding the dual-emission fluorescent molecularly imprinted polymer into a solution of a to-be-detected product, and carrying out fluorescence quenching reaction to obtain fluorescence intensity; and calculating the concentration of chrysin in the solution to be detected according to the standard curve. The preparation method is used for solving the technical problems that in the prior art, a single-emission fluorescent molecularly imprinted polymer has defects in the aspects of sensitivity, background fluorescence interference resistance in a complex environment and the like in the detection process.

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 relates to a method for specifically detecting tetrahydrocannabinol and hydride thereof by utilizing bridged beta-cyclodextrin, and belongs to the technical field of analysis and detection of supramolecular materials. The method comprises the following steps: firstly, combining 1, 6-hexamethylenediamine bridged bis-beta-cyclodextrin with an indicator to form a supramolecular probe; in a buffer system with a pH value of 9-11, tetrahydrocannabinol or a hydride thereof specifically competes to be combined with a cavity and displaces an indicator by utilizing a synergistic inclusion effect of a bridging subject and dissociation difference of guest molecules, so that the system is subjected to fluorescence quenching or color change, and a structural analogue cannabidiol does not generate obvious interference. The method solves the problems that the sensitivity is low and cannabidiol cannot be effectively distinguished in the prior art through cooperation of specific main body construction and environment regulation, has the advantages of being rapid in detection, high in specificity, high in accuracy and the like, and is suitable for environment monitoring and field screening.

The application discloses a double-line ratio fluorescent competitive immunochromatographic detection device and a preparation method and application thereof, and relates to the technical field of immunochromatographic detection.The detection device comprises a double-specificity recognition unit mixed-labeled quenched fluorescent probe, a background fluorescent material and a solid phase substrate, the solid phase substrate is provided with a T line on which a target object binding ligand is immobilized and a C line on which a quality control ligand is immobilized; and the application also provides application of the detection device in detection of exogenous harmful substances.The application solves the technical problem of low detection sensitivity of the existing method, and adjusts the binding amount of the probe on the T line and the C line through an immune competition reaction, adjusts the quenching degree of the background fluorescence based on an internal filter effect, takes (T line quenched fluorescent signal / background fluorescent signal) / (C line quenched fluorescent signal / background fluorescent signal) as a quantitative signal, and takes the C line to participate in ratio calculation to improve the detection sensitivity, so that the application is suitable for high-sensitivity qualitative and quantitative detection of small molecule compounds and the detection sensitivity is improved.