81 results about "Ratiometric fluorescence" patented technology

The invention discloses a method for quantitative detection of biological molecules capable of being metabolized to generate H2O2 in serum by means of a ratiometric fluorescent probe. The method includes firstly preparing copper-nitrogen codoped carbon dots Cu-CDs; then reacting corresponding oxidase and the biological molecules capable of being metabolized to generate H2O2 to generate H2O2; catalyzing the H2O2 and a substrate that is o-phenylenediamine with horseradish peroxidase to generate an oxidation product DAP having yellow fluorescence; then adding the Cu-CDs into the DAP; allowing the DAP and the Cu-CDs to form ratiometric fluorescence, with the ratio I<572>/I<460> of fluorescence intensities of the DAP and the Cu-CDs being in a linear relationship with the concentration of a substance to be detected; and performing quantitative assay of the biological molecules in the serum according to the ratio of fluorescence intensities. The method is high in sensitivity and simple and convenient in detection, and has high selectivity and high affinity of immunoreactions.

The invention provides a 1-(7-ethoxycoumarin)-4-(2-methyl-8-methoxyquinoline)-1, 2, 3-triazole ratiometric fluorescence or ratiometric ultraviolet absorption probe agent and preparation and application thereof, and belongs to the technical fields of organic synthesis and analytic chemistry. The preparation method is characterized in that an intermediate, namely, 2-methyl-8-(propyn-2-yl alkoxy) quinoline, reacts with 7-(2-azidoethoxy)-coumarin to obtain a compound a of which triazolyl is connected with two fluorophores, namely, coumarin and quinoline, wherein the compound is 1-(7-ethoxycoumarin)-4-(2-methyl-8-methoxyquinoline)-1, 2, 3-triazole. The preparation method has the advantages that the reaction raw materials are easy to obtain, the synthesis method is simple, and the compound can be obtained by three-step reaction; the compound a generates ratiometric fluorescence at 480nm and 390nm in alcohol/aqueous solution, and trace Al<3+> can be measured accordingly; ratiometric ultraviolet absorption is produced at 253nm and 243nm, and trace Al<3+> can be measured accordingly. The probe agent is the probe agent being high in sensitivity, high in accuracy and high in selectivity and used for detecting Al<3+> ions through ratiometric fluorescence and ratiometric ultraviolet absorption. The structure formula of the compound a is as shown in the specification.

The invention belongs to the technical field of chemical analysis detection, and particularly relates to a sulfite ratiometric fluorescence probe and a preparation method thereof. The molecular structural formula of the sulfite ratiometric fluorescence probe refers to description. The preparation method of the sulfite ratiometric fluorescence probe includes the following steps: reacting N1,N1 dimethyl benzene-1,4-diamine with crotonaldehyde to obtain N,N,2-trimethylquinoline-6-amine; reacting N,N,2-trimethylquinoline-6-amine with selenium dioxide to obtain 6-(dimethylamino) quinoline-2-formaldehyde; reacting 2,3,3-trimethylindoline with iodomethane to obtain 1,2,3,3-tetramethyl-3H-indoliu iodide; reacting 6-(dimethylamino) quinoline-2-formaldehyde and 1,2,3,3-tetramethyl-3H-indoliu iodide with piperidine to obtain the probe. According to the invention, molecular synthesis of the probe is simple, the cost is relatively low, the selectivity to sulfite is good, the preparation method is simple, raw materials are cheap and easy to obtain, and the method is easy to realize.

The invention discloses a tumor-targeted diagnosis and treatment integrated fluorescent probe which takes a tumor-targeted polypeptide sequence and an apoptosis enzyme specific recognition polypeptide sequence as a framework and comprises a fluorescence quenching molecular fluorescence pair and a photodynamic treatment photosensitizer. The diagnosis and treatment integrated fluorescent probe can achieve targeted treatment of tumors, and reduce toxic and side effects of the photodynamic treatment photosensitizer; a treatment result can be assessed in situ accurately in real time while the tumors are subjected to photodynamic treatment. The tumor-targeted diagnosis and treatment integrated fluorescent probe can also be used as a common fluorescent probe and used for screening of tumor treatment medicines and cell apoptosis imaging in a proportional fluorescence imaging manner. The tumor-targeted diagnosis and treatment integrated fluorescent probe can realize early detection of tumor treatment feedbacks and has great significance in promotion of accurate treatment of tumors and personal treatment.

The invention discloses a double-quantum-dot nano complex nitrogen monoxide ratiometric fluorescent probe and a preparation method thereof, belonging to the fields of nano technology and chemical analysis. The preparation method of the probe comprises the following steps: (1) carrying out reaction on mercaptopropionic-acid-stable CdSe quantum dots and a silane agent to obtain an amino-surface-functionalized CdSe@SiO2 core-shell complex; (2) dropwisely adding the mercaptopropionic-acid-stable CdSe quantum dot dispersion solution into the core-shell complex system to prepare a CdSe@SiO2-CdTe nano complex; and (3) introducing NO into the nano complex system, determining the fluorescence emission spectrum of the system, fitting the linear relationship between the CdTe/CdSe quantum dot ratiometric fluorescence intensity and NO concentration, and establishing the NO ratiometric fluorescent probe based on the CdSe@SiO2-CdTe nano complex. Compared with the prior art, the ratiometric fluorescence intensity introduced into the fluorescent probe can obviously enhance the NO detection accuracy and feasibility, and has important application value.

In some aspects, the present disclosure provides a dual emissive pH response noble metal nanoparticle which produces a ratiometric fluorescence signal based upon changes in the pH. In another aspect, the noble metal nanoparticle may be used in bioimaging applications as well as to detect in vivo changes of pH.

The invention provides a single-excitation double-emission carbon-based biomass dot as well as a preparation method and application thereof. The preparation method comprise S1, a proper number of clean Chinese cabbage leaves are weighted, and are ground in a utensil; S2, after absolute ethyl alcohol and an acetone solution according to the volume ratio of 1:0.9 to 1:1.1 are added, and then the mixture is uniformly mixed for being soaked; S3, after being soaked for 28-32 minutes, filtering is conducted to obtain a chlorophyll extracting solution; S4, 25 mL of chlorophyll extracting solution proportional to 0.1g-0.11g of polyoxyethylene diamine are added in a polytetrafluoroethylene reaction kettle, and mixing and heating are conducted for 9-11h under the temperature controlled to be 195-205DEG C; S5, after cooling to the room temperature is conducted, suction filtration is conducted, and a filtrate is adjusted to that with a pH value roundly equal to 7; and S6, the filtrate is transferred into a dialysis bag for lucifugal dialysis for 11-13h to obtain the single-excitation double-emission carbon-based biomass dot. According to the dot and the preparation method and application thereof, the carbon-based biomass dot can be directly used as a probe for ratiometric fluorescence imaging of active substance coenzyme A in cells, the background fluorescence interference of biological tissue can be eliminated, and the accuracy and the sensitivity of the fluorescence imaging of the coenzyme A can be improved.

The invention discloses a lysosome targeting hypochlorous acid ratio fluorescent probe and its preparation method and application. The molecular formula of the probe is: C ₄₉ h ₅₅ N ₇ o ₅ , the structural formula is as follows: The probe adds a lysosomal positioning group at the reaction site, and utilizes the energy transfer between two fluorescent groups to cause a change in fluorescence. A ratiometric probe for recognizing hypochlorous acid is designed and the response time is very fast, which can be applied Sensing detection of hypochlorous acid in a biological cell system; the sensing detection includes fluorescence detection, visual qualitative detection, and cell imaging detection.

The invention belongs to the technical field of fluorescent biological detection, and discloses a mercury ion detection method based on an enzymatic reaction double-emission fluorescent probe. The method comprises: laccase can catalytically oxidize 2, 3-diaminophenazine (DAP) generated by o-phenylenediamine (OPD), and an internal filtration effect existing between DAP and gold nanoclusters (AuNCs), so that the dual-emission fluorescent probe is obtained; using the characteristic that mercury ions have an inhibiting effect on laccase activity, and adding the mercury ions to reduce the laccase activity, so that the amount of DAP generated by catalysis is reduced, and sensitive detection of the mercury ions in an actual sample is realized. The response range of the ratiometric fluorescence sensing method based on enzymatic reaction to mercury ions is 8.0 * 10<-7>-35 * 10<-6> mol.L<-1>, the detection limit is 2.7 * 10<-7> mol.L<-1>, and a novel enzyme-based ratiometric fluorescence sensingmethod is provided for measuring mercury ions in an actual sample.

The invention discloses a ratiometric fluorescence biosensor for detecting aflatoxin-producing genes as well as preparation and application of the ratiometric fluorescence biosensor. A fluorescence energy donor of the fluorescence biosensor is a CQDsI-coated-SiO2-coated CQDsII hybrid nanosphere with a three-layer coating structure, a hairpin structure DNA sequence with two ends respectively modified with -SH and -NH2 is selected as a capture probe, and an energy receptor is AuNPs; when no toxin-producing gene appears, the AuNPs and the CQDsII are close in spatial distance, and FRET is triggered, so that fluorescence quenching of the CQDsII is caused; and when a toxin-producing gene exists, the toxin-producing gene is specifically paired with the fluorescent probe, so that the energy resonance transfer is blocked, the fluorescence of the CQDsII is recovered, and the fluorescence emission characteristic of the CQDsI is not changed due to the protection of the SiO2 nanospheres in the middle layer. The ratiometric fluorescent probe can provide a new thought for rapidly detecting aflatoxin toxin producing genes from the source.

The invention discloses a preparation method of a silver nanoparticle/sulfur quantum dot double-doped metal organic framework (MOF) compound ratio fluorescence exosome aptamer probe. The method comprises the following steps: reacting silver nanoparticles (AgNPs) with a precursor, doping AgNPs in an MOF structure, adsorbing zinc-doped sulfur quantum dots (Zn-SQDs) on the MOF surface, and attachingan aptamer/dopamine (Aptamer/DA) compound to form a nano composite aptamer probe; specifically combining the exosome (exosomes) and the aptamer to form an Aptamer/DA/exosomes compound; since the aptamer carries DA and is far away from the surface of the MOF, recovering Zn-SQDs blue fluorescence while AgNPs red fluorescence is almost unchanged; and fitting the linear relationship between the fluorescence peak intensity ratio IZn-SQDs/IAgNPs and the exosome concentration, and constructing a ratiometric fluorescence exosome aptamer probe.

The invention discloses a fluorescence method for rapidly detecting Hg<2+> in tea oil. The method comprises the steps of adding tea oil to be detected into a cyclohexane solution; then adding mercaptopropionic acid modified oil soluble CdTe QDs into the system; and detecting the content of Hg<2+> in the tea oil according to the quenching degree of the ratiometric fluorescence system CdTe QDs by utilizing the characteristic that red fluorescence of CdTe QDs can be quenched by Hg<2+> and fluorescence presented by the tea oil cannot be quenched by Hg<2+>. The fluorescence method capable of rapidly detecting Hg<2+> is designed by fully utilizing the characteristic that red fluorescence of oil-soluble CdTe QDs is complexed with Hg<2+> to cause fluorescence quenching, and has the characteristicsof high selectivity, high sensitivity and intuitive detection result.

The invention relates to a general polymer fluorescent platform applicable to a FRET fluorescent probe donor and application of the general polymer fluorescent platform, belonging to the technical fields of organic chemistry and high polymer material chemistry. According to the invention, methyl methacrylate and 4-allyloxy benzaldehyde are polymerized according to a reasonable ratio, and a coumarin fluorophore is further introduced through an efficient Schiff base reaction to prepare a general polymer blue-light platform MS-1 in the invention. The MS-1 is prepared from MS-1 and MS-2 step by step. The general polymer fluorescent platform prepared from the coumarin fluorophore has the advantages of easily available raw materials, simple and easy synthesis and low cost. When the general polymer fluorescent platform is combined with a mature long-wavelength fluorescent probe, proportional fluorescence detection of target molecules can be realized, and even visual detection with naked eyes can be realized through colors.

The invention relates to a ratiometric fluorescent probe for reversibly detecting sulfur dioxide/formaldehyde as well as a preparation method and an application thereof, and particularly relates to the ratiometric fluorescent probe which can be used for measuring, detecting or screening sulfur dioxide/formaldehyde and living cell fluorescence imaging, especially reversible colorimetric ratio detection of sulfur dioxide/formaldehyde. The probe can achieve at least one of the following technical effects: reversible detection of sulfur dioxide/formaldehyde, colorimetric ratio detection, high-selectivity recognition of sulfur dioxide/formaldehyde, rapid response to sulfur dioxide/formaldehyde, sensitive analysis of sulfur dioxide/formaldehyde, detection of sulfur dioxide/formaldehyde under physiological level conditions, and detection of sulfur dioxide/formaldehyde under physiological level conditions. The product has the advantages of simple synthesis and stable properties.

The invention belongs to the technical field of quantum dot fluorescent probe fluorescence detection, and especially relates to an application of a quantum dot fluorescent probe in visual detection ofHg < 2 + > in cells and human blood. The quantum dot fluorescent probe comprises silicon dioxide microspheres and 10Ca/6Tb: Bi2O2S nanocrystalline and aminated fluorescent carbon quantum dots, wherein the surface of the silicon dioxide microspheres is aminated and then is modified with a layer of 10Ca/6Tb: Bi2O2S nanocrystal, and the outer layer of the 10Ca/6Tb: Bi2O2S nanocrystal is further coated and modified with aminated fluorescent carbon quantum dots. The quantum dot fluorescent probe adopts SiO2 (at) 10Ca/6Tb: SiO2 (at) 10Ca/6Tb fluorescent probe, dual emission fluorescence can be realized, the quantum dot fluorescent probe can be used for a ratiometric fluorescence analysis method and does not depend on expensive instruments when being used for in-vitro analysis and can completelyperform quantitative or semi-quantitative analysis by naked eyes, can detect the fluorescence ratio intensity under two emission wavelengths or excitation wavelengths, can well correct errors causedby environment detection and improves the signal intensity.

The invention discloses a ratiometric fluorescence sensing method for visually identifying multiple organic solvents. The ratiometric fluorescence sensing method comprises the following steps: (1) preparing carbon dots; (2) preparing a gold cluster; (3) modulating the proportion of the fluorescent probe and carrying out liquid phase detection; and (4) performing preparation and visual detection ofthe fluorescent test paper. Fluorescent carbon dots and gold clusters are used as double fluorescent probes to construct a multicolor ratio fluorescence sensing mode. Because different types of organic solvents change different fluorescence intensities of the two probes, the fluorescence of the test paper can present different colors with large difference and is easy to distinguish by naked eyes,thereby realizing visual identification and detection of five organic solvents, namely methanol, acetonitrile, acetone, ethyl acetate and tetrahydrofuran.

The invention provides a fluorescent probe based on a rhodamine-indole derivative as well as a preparation method and application of the fluorescent probe, wherein the rhodamine-indole derivative has a chemical structural formula as the specification. The rhodamine-indole derivative can selectively acts on a bivalent palladium ion, a fluorescent light becomes from blue to orange, and the rhodamine-indole derivative has a ratiometric fluorescence effect, can be used for realizing naked eye discrimination and detection and is particularly used as the fluorescent probe applied to convenient detection of the parallelism ion in a cell.

The invention discloses a method for quantitatively detecting soluble beta amyloid protein (Abeta) by using a ratiometric type fluorescent probe and belongs to the technical field of medicines. According to the method disclosed by the invention, a metal ion ratiometric type fluorescent probe BPNS is obtained by coupling 2-pyridyl benzothiazole with a dansyl fluorophore. The method has the beneficial effects that the soluble Abeta has a high affinity for Zn<2+> or Cu<2+> and is capable of separating the metal ions from BPNS-metal ion adducts through chelation to trigger the ratiometric fluorescence response of the BPNS; the accurate quantitative detection of soluble Abeta aggregates can be realized by determining the linear relationship between the BPNS dual-wavelength fluorescence intensity ratio and the concentration of the soluble Abeta aggregates; and the method has a very good application prospect in the early diagnosis of AD.

The invention discloses a microcystic toxin ratiometric fluorescence sensor constructed based on a molecular imprinting technology, and belongs to the technical field of environment detection. According to the invention, carbon quantum dots taking citric acid as a carbon source and a nanomaterial of silicon dioxide-loaded fluorescein isothiocyanate are synthesized, the carbon quantum dots and the nanomaterial respectively have the characteristics of fluorescence quenching and fluorescence enhancement on microcystic toxins, so that a ratiometric fluorescence method is established, and then a molecular imprinting method is adopted, and metformin is taken as a false template, and the microcystic toxins are selectively recognized by leaving imprinting sites on the composite nano material, so that the effect of quantitative detection is achieved. The obtained CQDS-FITC-APTES-SiO2@MIP is good in microcystic toxin RR/LR fluorescence correspondence degree and sensitive in reaction, the fluorescence ratio technology and the molecular imprinting technology are combined, the rapid detection requirement of microcystic toxins is completely met, and the CQDS-FITC-APTES-SiO2@MIP is low in cost and suitable for being used in various occasions.

The invention provides dual-emission fluorescence carbon nanoparticles and a synthesis method and application thereof. According to the synthesis method of the dual-emission fluorescence carbon nanoparticles, o-phenylenediamine and ethanol amine serve as raw materials, and the dual-emission fluorescence carbon nanoparticles are prepared by adopting a solvothermal method. The dual-emission fluorescence carbon nanoparticles prepared by the invention generates dual emission fluorescence under stimulation of a single wavelength, and by adopting the dual emission wavelength, a proportional fluorescence detection system can be constructed to improve reliability of an analysis method.

The invention discloses a 9-acyl-3-iodocarbazole compound and application of the 9-acyl-3-iodocarbazole compound as a phosphorescent material. The invention specifically discloses a carbazole compound containing a fragment I. The 9-acyl-3-iodocarbazole compound provided by the invention has a very high phosphorescence emission proportion in a steady-state luminescence spectrum, has a phosphorescence emission proportion exceeding 90%, and has a very low fluorescence emission proportion; and meanwhile, visible light can excite phosphorescence of the compound, and bright phosphorescence emission can be shown in a molecular dispersed solution at room temperature.

The invention proposes an imidazo[1,2-a]pyridine ratiometric pH fluorescent probe and a preparation method thereof, and the probe is used for the determination of extremely acidic pH changes in living cells and Escherichia coli. The preparation method is as follows: under the protection of an inert gas, N, N-dimethylbenzaldehyde or its derivatives, 4-chloroaniline and sodium bicarbonate are dissolved in methanol, and heated to reflux to obtain a crude product; and 2-(4-methoxyphenyl)-7-methylimidazo[1,2-a]pyridine dissolved in N,N-dimethylformamide, with potassium tert-butoxide as alkaline reagent, heating Reflux reaction; separated by silica gel column. The probe exhibits ratiometric emission fluorescence characteristics under extremely acidic conditions, and at the same time has the ability to H ⁺ It has the advantages of high sensitivity, good selectivity and large Stokes shift.

The invention belongs to the technical field of fluorescent materials, and particularly relates to a hypochlorous acid activated near-infrared fluorescent probe as well as a preparation method and application thereof. The invention adopts a new strategy to construct a high-proportion fluorescence-enhanced near-infrared organic small molecule fluorescent probe with hypochlorous acid response. The fluorescent probe comprises a luminous core based on a boron dipyrromethene near-infrared fluorescent dye with excellent light stability and chemical stability; ferrocene is introduced into the fluorescent dye as a quenching element to obtain a series of probes. The fluorescence change condition of the series of probes under the action of hypochlorous acid is studied, and the near-infrared fluorescent dye with high activation rate and long emission wavelength is obtained. The Fc2-BDP series fluorescent probe obtained by the invention has good fluorescent response performance, relatively low detection limit and excellent stability, and can be used for high-sensitivity imaging of inflammations such as lymphatis and enteritis.