311 results about "Intense fluorescence" patented technology

A method for preparing carbon nitride quantum dots comprises the following steps of (1) material preparation, (2) drying and tabletting, (3) heating, (4) separation and (5) drying. Sodium chloride crystals are used as a template, the preparing process is simple and low in cost, and the sodium chloride crystals can be easily removed through water dissolution; melamine is used as the raw material, and annular carbon nitride basic structural units exist in melamine molecules, so that the yield of preparing the quantum dots is high, and product size uniformity is good; the prepared quantum dots are high in specific area, good in water solubility and good in dispersity, have strong fluorescent radiation visible under naked eyes, and have wide application prospects in the fields of fluorescence detection, light emitting devices, biomarker and the like.

Particle analyzing systems with fluorescence detection are disclosed, primarily in connection with particle sizing based on scattered light intensity or time-of-flight measurement. In one system, emission of fluorescence is used as a threshold for selecting particles for further analysis, e.g. mass spectrometry. In another embodiment, laser beams arranged sequentially along an aerosol path are selectively switched on and off, to increase the useful life of components, and diminish the potential for interference among several signals. Other embodiments advantageously employ color discrimination in aerodynamic particle sizing, single detectors positioned to sense both scattered and emitted fluorescent radiation, and laser beam amplitude or gain control to enhance the range of fluorescence detection.

Textile fibers and other fibrous substrates functionalized with particles are provided for use in the detection of targets of interest by spectroscopic methods. In one embodiment, a substrate is provided that comprises a conformal coating on its surface, wherein the coating comprises a plurality of chemically functional particles that are spectroscopically enhancing. Methods for producing such functionalized textile fibers are also provided. These textiles can be used as platforms for spectroscopic detection, including surface-enhanced Raman scattering (SERS), surface-enhanced infrared absorption (SEIRA), and surface-enhanced fluorescence (SEF). Functionalized textile fibers for use in the signature detection methods are produced by performing layer-by-layer self-assembly of particles on natural and synthetic textile substrates.

The present invention is directed to optical structures and methods detecting the fluorescence of a molecule using metal-enhanced fluorescence. In particular, the invention describes the use of surface plasmon excitation for excitation of fluorophores near the metal surface and the efficient collection of the emission by coupling into the plasmon resonance and directing towards the detector. More particularly, the present invention makes use of the unique directionality of the plasmon induced fluorescence signal. The present invention is directed to optical structures using metal enhanced fluorescence including: an optical fiber having a conductive external coating; a light emitting diode (LED) having a conical shaped depression with curved sides on a front end surface, the curved sides having a conducting coating on the outer surface with respect to the LED.

Methods and compositions involving enzyme-activatable fluorophore polymer imaging agents for photodetection of specific tissues and / or human diseases and disorders are provided. In certain embodiments, the imaging agent comprises a hydrophilic polymer backbone (e.g., poly(L)lysine), a hydrophobic fluorophore, and a hydrophilic solubilizing agent. The solubilizing agent may comprise a quarternary ammonium group (e.g., a 1-methylnicotinic group) to enhance self-quenching of the fluorophore. Various methods for the generation and purification of imaging agents are also provided, including methods involving solid phase probe extraction or ion exchange purification.

The invention belongs to strong-fluorescence boron dipyrromethene dyes containing a carbazole structure in the technical field of organic chemical industry and fine chemical industry. Because a method for preparing the strong-fluorescence boron dipyrromethene dye containing the carbazole structure and derivatives thereof adopts boron dipyrromethene and carbazole aldehyde with substituent as raw materials, the molar ratio of the boron dipyrromethene to the carbazole aldehyde is 1:2-5, piperidine is a catalyst, a 4-angstrom molecular sieve is a dehydrating agent, and the molar ratio of the borondipyrromethene to the catalyst is 1:0.01-0.20; in an organic solvent, at the temperature of between 100 and 150 DEG C and under the protection of argon or nitrogen, the mixture reacts for 8 to 50 hours by stirring, the carbazole aldehyde and the active methylene of the boron dipyrromethene are dehydrated to generate the boron dipyrromethene derivatives; and after the carbazole structure with different substituents is introduced into the boron dipyrromethene, the optical property of the boron dipyrromethene compound is changed, the red shift of the absorption spectrum thereof is 80 nanometers, the red shift of the emission spectrum is 90 nanometers, higher fluorescence quantum yield is kept at 0.67, the laser efficiency reaches more than 30 percent, and the strong-fluorescence boron dipyrromethene derivatives containing the carbazole structure are obtained.

The invention provides a fluorescent probe represented by the formula (I), wherein R1 and R2 are independently selected from H or an aromatic vinyl group, and at least one of R1 and R2 is the aromatic vinyl group; R3 is selected from H, F, Cl, Br, OH, OCH3, N(CH3)2 or C1-C6 alkyl; and R4 is selected from C1-C6 alkyl. Compared with the prior art, because the fluorescent probe provided by the invention has a relatively large electronic conjugated system and plane, the intensity of the intramolecular charge transfer effect can affect the molecular fluorescence emission intensity; when the fluorescent probe and the G-quadruplex generate a specific action, the flexibility of intramolecular rotatable double bonds is restricted, the intramolecular charge transfer effect is enhanced, and the fluorescence is also enhanced significantly; moreover, the fluorescent probe provided by the invention has the advantages of low biotoxicity, phototoxicity and photobleaching property, good light stability, good water solubility and good cell membrane permeability.

The invention discloses a method for preparing graphene quantum dots through a carbon nano tube. The method comprises the following steps of: adding a mixed solution of nitric acid and sulfuric acid into the carbon nano tube, heating in a water bath, magnetically stirring, cooling to room temperature, diluting by using distilled water, regulating the pH value, performing dialysis and ultrafiltration centrifugation, and extracting through an organic solvent, so as to prepare the graphene quantum dots. The carbon nano tube which is diversified in growth modes and easy to control serves as a raw material, the graphene quantum dots are prepared through simple and controllable water bath heating and stirring operation; and the graphene quantum dot has the characteristics of good fluorescence effect, controllable fluorescence range, water solubility and the like, can be soluble with most of polymers through extraction and can be applied to the improvement of the device performance in photoelectric materials and devices.

A compound represented by the following general formula (I):{R1, R3, R6 and R8 are methyl groups and the like, R2 and R7 are cyano groups and the like, R4 and R5 are fluorine atoms and the like, and X is a group represented by the formula (A) [R11 is a monocarboxy-substituted C1-8 alkoxy group and the like, R12, R14 and R15 are hydrogen atoms and the like, and R13 is hydroxy group and the like],provided that the combination of the aforementioned substituents is such a combination that the compound represented by the formula (I) can be substantially non-fluorescent before reacting with peroxynitrite, and the compound represented by the formula (I) in which the group represented by the formula (A) is nitrated after reacting with peroxynitrite can be substantially highly fluorescent}, or a salt thereof, which is useful as a fluorescent probe for peroxynitrite measurement.

The invention discloses a fluorescent probe used for detecting glutathione as well as a preparation method and application thereof. According to the invention, 1, 8-naphthalimide is used for building a classical ICT system, a phenyl sulfone part is introduced to the position of 4-, the ICT effect of a probe molecule is regulated and controlled, and due to the strong attracting electron effect of the phenyl sulfone in the position of the 4-, the probe molecule self is free from fluorescence emission. In case of the existence of glutathione, the phenyl sulfone part can be replaced by the glutathione, further the intramolecular electron transfer from sulphur atom in the position of the 4- (from glutathione) to the 1,8-naphthalimide can be generated, moreover, the ICT effect enables the probe molecule to send out strong fluorescence. The fluorescent probe provided by the invention can realize detection to the glutathione in cells, and has the advantages of being convenient and simple to operate, low in cost, sensitive in response, easy for popularization and application and the like.

The invention discloses nitrogen carbide quantum dot fluorescence ink. By virtue of a hydrothermal synthesis method, a colorless and transparent nitrogen solution with strong fluorescence characteristics is prepared, and nitrogen carbide quantum dots of the water solution are uniform in shape and controllable in size; a maximal fluorescence-emission peak can be detected at 368 nanometers by virtue of excitation of a 250-nanometer wavelength, and most emission peaks are projected to invisible regions; when the nitrogen carbide quantum dot fluorescence ink is applied to encrypted storage protection of fluorescence information, the encrypted information cannot be read by virtue of ultraviolet color development, and fluorescence signals can be converted into readable information by virtue of a specific instrument. Compared with a traditional method, the method has the advantages that read equipment is relatively specific, and the information encryption is relatively strong.

The present invention relates to a two-photon fluorescent probe, more particularly a two-photon fluorescent probe represented by Formula 1, a method for preparing same and a method for imaging thiols in mitochondria using same. The two-photon fluorescent probe according to the present invention, having two probes introduced in one molecule, can selectively dye mitochondria and emit intense fluorescence by reacting with thiols. Accordingly, it can be used to image the distribution and activation of thiols in a living cell or an intact living tissue.

The invention discloses a fluorescent probe containing N, N-diethyl paramethylaminophenol and application thereof in the thiophenol detection. The structural formula of the fluorescent probe is as follows: in a phosphate buffered solution with pH value of 7.4, the compound can be in nucleophilic substitution reaction with thiophenol for releasing out the strong fluorescent material 3-(N, N-diethyl)-6-hydroxy-fluorane, so that the reaction system has a strong fluorescent signal at the wavelength of 543 nm; experimental results show that the fluorescent probe is used to detect the thiophenol; the detection limit of the thiophenol is 6.0*10<-9>mol / L; the relative standard deviation is 2.6%; the qualitative and quantitative detection of the thiophenol can be realized. The detecting method is simple in operation, high in accuracy and sensitivity and good in selectivity; different thiol compounds have no disturbance to the system of the fluorescent probe detecting the thiophenol; the fluorescent probe can be used for detecting the content of the thiophenol in a water sample.

The invention discloses a method for preparing a water-soluble mercury ion fluorescence probe on the basis of rhodamine and application of the water-soluble mercury ion fluorescence probe. A structural formula of the Hg<2+> fluorescence probe are shown, and the water-soluble mercury ion fluorescence probe is synthesized from 1, 2, 4-trimellitic anhydride, 3-diethylamino phenol and hydrazine hydrate. The method and the application have the advantages that the water-soluble Hg<2+> fluorescence probe prepared by the aid of the method is simple in structure, is based on rhodamine derivatives and is the first fluorescence probe for detecting Hg<2+> in 100% aqueous solution by the aid of rhodamine lactam derivatives; ring opening of rhodamine lactam structures can be carried out under the induction effects of the Hg<2+> in systems, intense fluorescence can be generated, and the water-soluble mercury ion fluorescence probe is high in Hg<2+> detection sensitivity; the fluorescence probe is excellent in Hg<2+> selectivity and is almost free of interference of other positive ions; the Hg<2+> can be measured by the fluorescence probe without disturbance when pH (potential of hydrogen) values range from 5.0-8.0, the fluorescence probe and the Hg<2+> can act quickly, and the response time is shorter than 3 minutes; the probe further can be applied to measuring Hg<2+> in environmental water samples and carrying out fluorescence imaging on Hg<2+> in biological cells.

The invention pertains to the technical field of nanometer supramolecular materials, and relates to a nanometer supramolecular assembly of a perylene diimide derivate modified by full methylated Beta-cyclodextrin loaded by polyvinylidene fluoride membrane and a preparation method thereof. The chemical formula of the molecular assembly is C138H226N2O72, and the structure thereof is shown as in an attached drawing. The perylene diimide derivate modified by the red fully methylated Beta-cyclodextrin is dissolved to obtain the nanometer supramolecular assembly. The method adopts the strong fluorescence of solid perylene as a detecting singnal, takes an empty chamber of the fully methylated Beta-cyclodextrin as a receptor of an air molecule, thereby solving two difficulties of strong fluorescence in a solid state in the construction of a fluorescence sensor and the introduction of a suitable air molecular receptor. The nanometer supramolecular assembly of the perylene diimide derivate modified by full methylated Beta-cyclodextrin loaded by PVDF member realizes quick detection of the fluorescence sensing function of the air molecules of nitromethane, nitroethane and nitrobenzene in 10s.

The invention relates to an image fusion method and system. The method comprises the steps: obtaining a source image, wherein the source image comprises a fluorescence image and a visible light image;carrying out two-scale decomposition on the source image by adopting a Gaussian filtering method to obtain a base layer image and a detail layer image of the source image; constructing a weight map of the highlighted fluorescence information by using a nonlinear function; fusing the base layer image corresponding to the fluorescence image and the base layer image corresponding to the visible light image to obtain a base layer image of a fused image; constructing a second weight map for enhancing fluorescence information based on significance detection; fusing the detail layer image corresponding to the fluorescence image and the detail layer image corresponding to the visible light image to obtain a detail layer image of the fused image; and reconstructing the base layer image of the fused image and the detail layer image of the fused image to obtain a fused image. According to the invention, the complexity of a multi-scale algorithm can be reduced, and the image fusion efficiency isimproved.

The invention provides preparation and application of a mercury ion sensor based on photonic crystal enhanced fluorescence. The mercury ion sensor is composed of photonic crystal, a nucleic acid fluorescence molecular probe and a DNA assistant probe. The photonic crystal is used as a substrate, and strong affinity between thymidine (T) of DNA and Hg<2+> is employed to allow fluorescence group ROX labeled aptamer and a complementary sequence to compose a fluorescence detection system. A photonic crystal film is formed on a glass sheet substrate by prepared PS microspheres through vertical deposition self-assembly. Gold is sprayed on the surface of the photonic crystal; and based on Au-S bonding effect, mercapto group modified fluorescence group ROX labeled aptamer undergoes self-assembly on the surface of the photonic crystal, wherein the emission wavelength of ROX accords with the forbidden band of the photonic crystal, so fluorescence enhancing effect is achieved. According to the invention, fluorescence signal intensity of a nucleic acid fluorescence molecule is improved by using the principles of enhancement of fluorescence through the photonic crystal, so sensitivity and accuracy of sensor detection are improved.

The invention relates to a carbon quantum dot-copper ion fluorescent probe and a preparation method and application thereof. The method includes that carbon quantum dots with strong fluorescence are synthesized by the aid of a microwave hydrothermal method, fluorescence strength of the carbon quantum dots are greatly reduced by the aid of copper ions, the copper ions are composited on surfaces ofthe carbon quantum dots, surface energy is transferred, CQDs / Cu<2+> with weak fluorescence is formed, a glucose solution is added, pH value is adjusted to 7, heating is performed at the temperature of80DEG C, glucose and the copper ions undergo 'copper mirror reaction' to be oxidized to gluconic acid, and the copper ions are reduced to be precipitated to be Cu2O2. The fluorescence spectrum test shows that after the glucose solution is added, glucose is catalyzed and oxidized through the copper ions on the carbon quantum dots CQDs for reaction and is removed from surfaces of the CQDs, and thestrong fluorescence on the CQDs is restored. The carbon quantum dot-copper ion fluorescent probe based CQDs / Cu<2+> is applicable to effective detection of the glucose under non-enzymatic environment.

The invention discloses a preparation method and applications of hexatomic dinitrogen heterocyclic derivatives containing four identical substituent groups, and belongs to the field of application technology of luminescent materials in preparation of organic light-emitting devices. According to the preparation method, pyrazine and pyridazine are taken as electron acceptors of luminescent materials; the periphery of the electron acceptors is connected with electron donors such as carbazole, phenoxazine, and 9,9-dimethyl-9,10-dihydracridine; frontal orbital overlapping degree of HOMO and LUMO is adjusted, so that luminescent materials with thermally activated delayed fluorescence (TADF) characteristics are obtained. At room temperature, the hexatomic dinitrogen heterocyclic derivatives possess strong absorption at ultraviolet-visible region, a dilute solution of the hexatomic dinitrogen heterocyclic derivatives is capable of emitting strong fluorescence, the wavelength of emission peaks ranges from 450 to 615nm in the blue light-orange light range, the hexatomic dinitrogen heterocyclic derivatives can be applied to organic light-emitting devices as luminescent materials. According to devices based on compound M2, turn-on voltage is 3.9V, the maximum brightness 3846cdm<2> is achieved at a voltage of 12V; and the maximum luminous efficiency 17.4cdA<1> and the maximum power efficiency 12.21mW<1> are achieved when electric current density is 0.06mAcm<2>(4.5V).

The invention provides a pyrene derivative fluorescent probe molecule for recognizing and detecting formaldehyde as well as a preparation method and application of the fluorescent probe molecule. Thepreparation method provided by the invention has simple synthetic steps only needs one step reaction and has a higher yield. The fluorescent probe provided by the invention does not have fluorescencein an HEPES buffer system, but can react specifically with the formaldehyde to generate a product with strong fluorescence, so as to achieve specific selection and quantitative analysis for the formaldehyde. The recognition characteristics of the probe B1 with aldehydes and amino acids in the HEPES buffer system are studied by a fluorescence spectrometer, results show that the probe B1 has high-efficiency specific selectivity for the formaldehyde, the lowest detection limit of the probe for the formaldehyde is 0.107[mu]M, and the probe has broad application prospects in the field of biomolecule detection.

The present invention discloses size controlled and stabilized nano-aggregates of molecular ultra small clusters of noble metals and a process for the preparation thereof. The present invention discloses single source multicolor noble metal spherical and uniform nano aggregates of 10-22 nm made up of discrete molecular ultra small noble metal (Nb) nanoclusters (MUSNbNC's) of 1-6 atoms. The MUSNbNC's are capped with amine / DCA (dicarboxy acetone) group acting as a steric and kinetic hindrance for core growth suppressing the further autocatalysis and conversion of super critical nucleus or growth by ripening and formation of nanoparticles and thus having intense fluorescence.

The invention provides a preparation method and application of a fluorescence-MRI (Magnetic Resonance Imaging) dual-mode image probe, and particularly relates to a dual-mode image probe which combines a fluorescent nanoparticle and a paramagnetic contrast agent and a preparation method thereof, belonging to the field of functional materials. The main process of the method comprises the following step of: removing residues and moisture through dialysis and freeze-drying by taking an amino compound as a surface passivation agent and a gadolinium-based complex as a carbon source material and adopting a one-step forming method to obtain a fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot. The method provided by the invention ahs the characteristics of simple process, low cost and easiness for large-scale production. The fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot prepared through the method has the excellent characteristics of higher fluorescent property, higher relaxation efficiency, good biocompatibility and the like, is successfully applied to in-vitro live cell fluorescence imaging and in-vivo magnetic resonance imaging; the fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot synthesized through the method is about to have wide application prospect in the field of biomedicine.

The invention belongs to the field of a nanometer material science and a laser Raman detection technology, and particularly relates to a preparation method of a self-assembled silver ball SERS (Surface Enhanced Raman Scattering) base with a controllable silver nano sheet thickness. The method takes silver nitrate as a silver source and L-ascorbic acid as a reducing agent, and comprises the following steps of: adding one organic acid with controlled amount to react in an ice bath (2-5 DEG C) for 2-15 minutes to obtain a silver micro-ball which is formed by self-assembling silver nano sheets with the controllable thickness in a range of 20-110nm. The silver micro-ball formed by self-assembling the silver nano sheets, which is prepared by the method, not only has the characteristic of high specific surface area of a common nano material, but also has the characteristics of controllable thickness of the surface silver nano sheets and serial and comparable surface roughness; and the silver micro-ball formed by self-assembling the silver nano sheets is a surface enhanced Raman base with the very good activity and is hopeful to be applied to aspects of surface enhanced fluorescence and photocatalysis.

Compositions comprising fluorescent or colored dyes and methods of using the same in combination with divalent metal salts to analyze samples are disclosed.

The embodiment of the invention discloses an image fusion method for a medical fluorescence imaging system in the technical field of medical fluorescence imaging, and the method comprises the following steps: S1, carrying out the saliency region detection of a visible light image, obtaining a saliency map Svis, and carrying out the saliency region detection of a fluorescence image, and obtaining asaliency map Sflu; S2, calculating a fusion weight of the visible light saliency map and the infrared light saliency map; and S3, performing image fusion on the fluorescence image and the visible light image, and outputting a fusion image result. According to the method, the fusion weight is calculated by adopting the saliency map, and pseudo-color image fusion is carried out in the RGB color space, so that fluorescent region features can be highlighted, texture features of a fluorescent stimulated region can be enhanced, and the fused image is more natural and comfortable in impression; andthe fused image can effectively reserve key information in the image, enhance fluorescence characteristics in the fused image and highlight texture information of a fluorescence region.

The invention discloses a preparation method and an application of a copper nano-cluster solution. Polyethyleneimine is used as a template, and hydrazine hydrate is used as a reducing agent, so as to synthesize into a copper nano-cluster with stronger fluorescent property; the fluorescence of the material is quenched by trace Au (III) ions, and accordingly a new method for measuring the Au (III) ions is established. The preparation method has the advantages that the operation is simple, the detection limit is low, and the Au (III) can be quickly and accurately detected; the copper nano-cluster solution is used as a probe, the Au (III) is detected by fluorescence spectrophotometry, and a new concept is provided for the detection of Au (III).

The invention discloses a compound (I) P-N-methyl cyclopentaldehyde rhodamine 6G pH fluorescence molecular probe as well as a preparation method and use thereof. When hydrogen ions are present in the detected environment, under the action of hydrogen ions, the rhodamine 6G lactam spiral ring in the probe molecular compound (I) is opened in ring from closed state, and the color of the solution is obviously changed from achromatic color to orange red with strong fluorescence-emission. The compound I can be used for high-sensitivity naked eye color identification for hydrogen ions and also used as a fluorescent identifying probe.

The invention discloses a production method of silver-clad gold nano-rods and their application and belongs to the technical field of food quality detection and analysis. Au@ag nano-rods are produced, and with the surface enhanced fluorescence of the nano-rods, the nano-rods are successfully applied to the detection of the gene O157:H7easeA of E. coli. Compared with the traditional methods, the method has the advantages that detection limit is greatly lowered, sensitivity is improved, and good stability is achieved. According to the principle of fluorescence enhancement-weakening, a standard curve for gene O157:H7ease detection of E. coli is built, a linear range is from 10<-17> M to 10<-11> M, correlation coefficient R2 is 0.9947, and the detection limit is 3.33*10<-18> M (S / N = 3). The method has the advantages that specificity is good, labelling experiments show that eaeA gene recovery rate is 98.36% to 101.67%, with good stability, and the nano-rods are applicable to the detection of the gene O157:H7ease of E. coli and have a promising application prospect.

The invention relates to a method for quickly preparing a silver nanocluster with strong fluorescence emission. The method is characterized in that by volume, 14.75 parts of redistilled water is put into a container, 2.0 parts of AgNO3 solution, 0.25 parts of NaBH4 solution and 3.0 parts of amino black 10B are added into a thermostat water bath in sequence in a mixing condition, so as to be mixed for 3 to 90 min at 30-80 DEG C, and then the silver nanocluster with strong fluorescence emission can be obtained. According to the method, a biological dye of amino black is used as a stabilizing agent, and the silver nanocluster with strong fluorescence emission can be prepared after 10 min. The method has the advantages of easiness in obtaining raw materials, simple system, short synthetic time, strong fluorescence and smaller size.

The invention provides compounds and compositions of Formulas I-VII, and methods of using the compounds. The compounds can be used to prepare dye conjugates that are uniformly and substantially more fluorescent on proteins, nucleic acids or other biopolymers, than conjugates labeled with structurally similar known carbocyanine dyes. In addition to having more intense fluorescence emission than structurally similar dyes at virtually identical wavelengths, and decreased artifacts in their absorption spectra upon conjugation to biopolymers, the compounds can have greater photostability and / or higher absorbance (extinction coefficients) at the wavelength(s) of peak absorbance than such structurally similar dyes.