65results about How to "High fluorescence stability" patented technology

There is a kind of nano particle and micro-sphere biological fluorescence probem and the manufacturing method. The method mainly includes: 1) hydrosulphenyl compound with amidocyanogen is used as stabilizing agent in particle synthesis, water-soluble fluorescence nano particle whose surface is bedecked with amidocyanogen is directly prepared under mild condition, then it takes advantages of the amidocyanogen on the surface of particle to couple with biological system directly, further nano-particle biological fluorescence probe is acquired; 2) said fluorescence nano particle whose surface is bedecked with radical dumpling with different functions is compounded into micro-sphere is inorganic silicon dioxide or organic polymer by various means, fluorescence micro-sphere which can be dispersed equably in aqueous solution is acquired.

The invention provides a preparation method for a fluorescence sensing material based on molecular imprinting and carbon dots. The method comprises the following steps: adding a substitute template and a functional monomer into a mixed solution composed of chloroform, acetonitrile and toluene, carrying out stirring and allowing the mixed solution to fully dissolve and react, then adding the carbon dots, carrying out stirring and then adding a crosslinking agent and an initiator, carrying out ultrasound and then introducing nitrogen for water bath and incubation, carrying out filtering, carrying out placing in a vacuum drying oven for aging, carrying out washing with an extracting solvent so as to remove template molecules, and carrying out vacuum drying so as to obtain a molecular imprinting and carbon dot fluorescent sensing material. The preparation method for the fluorescence sensing material provided by the invention has the advantages of high stability, light-free bleaching, low toxicity and capability of directly forming a sensing material by embedding into molecular imprinting polymer through polymerization reaction without the need of subsequent modification; and the sensing material in the invention is simple in preparation process, and has specific recognition effect of the molecular imprinting polymer, strong fluorescence characteristic of the carbon dots, and selective recognition effect to sterigmatocystin.

The invention discloses a biological thiol fluorescent probe. According to the biological thiol fluorescent probe, a first fluorophore is used as an energy donor for emitting fluorescence, and a second fluorophore or quenching group is used as an energy acceptor for absorbing fluorescence. The biological thiol fluorescent probe has the structure of R-S-S-R', wherein R comprises the first fluorophore, and the R' comprises the second fluorophore or quenching group. The invention further provides a preparation method and an application of the biological thiol fluorescent probe. The biological thiol fluorescent probe uses the fluorescence intensity per se to attenuate or quench, thus the imaging signal to noise ratio is increased. In addition, the biological thiol fluorescent probe has high fluorescence stability after the thiol is subjected to reaction. The biological thiol fluorescent probe is easy to prepare and can be prepared at normal temperature and pressure and neutral pH value.

The invention discloses preparation of near-infrared fluorescence nanoparticles and an application method of the near-infrared fluorescence nanoparticles in an imaging technology. A loaded near-infrared fluorescent dye is taken as a luminescence center, and chitosan and polylysine are taken as basic skeletons, so as to prepare the near-infrared fluorescence nanoparticles by self-assembling package of sodium alginate into a shell. A transmission electron microscope displays the mean grain sizes of the near-infrared fluorescence nanoparticles are about 15nm; a dynamic scattering test indicates that the mean dynamic hydration radius is less than 160nm; the photostability of the near-infrared fluorescence nanoparticles is significantly enhanced in comparison with fluorescent dye molecules; the near-infrared fluorescence nanoparticles can stably exist in 0-1.5% NaCl aqueous solution.

The invention provides a preparation method of food-borne fluorescent nanoparticles. The preparation method comprises the following steps: S1: baking salmon or Spanish mackerel at 150 to 350 DEG C for10 to 150 min; S2, immersing a baked sample into a polar organic solvent and extracting; carrying out rotary evaporation on an extracted mixed solution until the polar organic solvent is completely removed, wherein the mass and volume ratio of the sample to the polar organic solvent ranges from (1 to 1) to (1 to 3) and the extracting time is 2 to 48h; S3: re-dissolving by adopting water and a non-polar organic solvent and carrying out liquid separation to remove a non-polar organic solvent layer; adding the non-polar organic solvent and repeatedly extracting and degreasing until a water-phasesolution is clarified and transparent, wherein the mass and volume ratio of the sample to the non-polar organic solvent added each time ranges from (1 to 1) to (1 to 3); enabling water-soluble extract to be subjected to liquid column chromatography for collecting a fluorescent part; carrying out freeze-drying to obtain the product. The method provided by the invention breaks through a traditionalfluorescent nanoparticle preparation manner and has the advantages that a preparation process is simple and a prepared case has high biological safety and the like.

The invention belongs to the fields of cell imaging and preparation of nanometer nucleic acid quantum dot reagents, and in particular relates to a stable near-infrared silver nucleinate nanometer cluster as well as a preparation method and applications of the stable near-infrared silver nucleinate nanometer cluster in cell imaging. The nucleotide sequence is taken as a template, in sodium citrate buffer solution, NaBH4 is adopted for reducing AgNO3, and thus the silver nucleinate nanometer particles with the near-infrared fluorescence are synthesized. The silver nucleinate nanometer particles can emit 800nm fluorescent light under the exciting wavelength being 750nm, the size of the silver nucleinate nanometer cluster is 70nm. The silver nucleinate is high in stability, and can be used for the fluorescent imaging of tumor cells.

The invention relates to a quantum-dot nanometer particle containing a hydrophobic interlayer and a preparation method thereof. The particle is composed of a core, a hydrophobic interlayer and a shell from inside to outside; the core is a quantum-dot nanometer particle or a magnetic quantum-dot nanometer particle; the hydrophobic interlayer has a compact hydrophobic structure, and comprises an intrinsic surface ligand molecule of the quantum-dot nanometer particle or the magnetic quantum-dot nanometer particle, an ionic surfactant containing a saturated aliphatic chain and a silicon precursor reagent containing a saturated aliphatic chain; the shell is a silicon dioxide shell; and the particle size of the core is more than 3 nm and less than 10 nm, and the shell thickness is 0.6-0.7 nm. The water-soluble quantum dot with high quantum yield is prepared for the first time, and the hydrophobic interlayer is capable of effectively preventing factors going against fluorescence emission in the environment, and therefore the quantum dot or magnetic quantum-dot nanometer particle with high fluorescent quantum yield is obtained.

The invention discloses a method for synthesizing Cu doped CdxCu1-xTe quantum dot by using a hydrothermal method; the preparation method comprises the following operation steps of: in the presence of nitrogen, injecting a pre-prepared sodium tellurium hydride NaHTe solution in a pre-prepared mixed solution of cadmium salt, copper salt and water soluble N-acetyl-L-cysteine, to obtain a CdxCu1-xTe precursor solution; then putting the solution in a hydrothermal reaction kettle, reacting to prepare the Cu doped CdxCu1-xTe quantum dot with adjustable fluorescence-emission wavelength and high fluorescence quantum dot yield. The hydrothermal method disclosed by the invention is low in cost, convenient to control, environmentally-friendly, and the like; the obtained Cu doped CdxCu1-xTe quantum dot is high in fluorescence stability, excellent in biocompatibility and low in toxicity, and is expected to be used widely in biochemical analysis and biomedical fields as novel fluorescence nano probe.

An immunohistochemical analysis and detection method based on quantum dots in the field of nanomaterials, comprising the following steps: (1) first dispersing the quantum dots in a borate buffer solution, then adding diimide sulfide and a secondary antibody, mixing , react, centrifuge, and wash to obtain the African swine fever monoclonal antibody complex labeled with quantum dots; wherein, quantum dots: diimine sulfide: the molar ratio of the secondary antibody is 60: 15: 1; or (2) first the quantum dots Disperse in a phosphate buffer solution containing 1.25% glutaraldehyde by volume, disperse, react, add a secondary antibody, react, centrifuge, and wash to obtain a quantum dot-labeled African swine fever monoclonal antibody complex; wherein, the quantum dot The molar ratio of :glutaraldehyde:secondary antibody was 60:15:1; after that, immunoreaction and observation were carried out according to the standard immunohistochemical detection method. The method of the invention directly observes with a fluorescent microscope, is simple and easy to implement, increases the stability of the fluorescent light, and improves the accuracy of analysis and the sensitivity of detection.

The invention discloses a method for preparing a fluorescent tungsten oxide quantum dot through a solvothermal process, the prepared fluorescent tungsten oxide quantum dot and application of the fluorescent tungsten oxide quantum dot, belonging to the technical field of nanometer materials. The method comprises the following concrete steps: dispersing tungsten disulfide powder in an alcohol solvent to obtain a dispersion of tungsten disulfide; adding hydrogen peroxide into the dispersion, and carrying out uniform mixing under stirring to obtain a mixed solution; transferring the obtained mixed solution into a reaction vessel, sealing the reaction vessel and then carrying out a high-temperature reaction; subjecting a reaction solution obtained in the previous to vacuum pumping filtration, and collecting a filtrate for dialysis; and freezing collected dialysis fluid and then carrying out vacuum freeze-drying to obtain tungsten oxide quantum dot powder. The preparation method provided by the invention is simple, green and environment-friendly, uses easily available raw materials and has high controllability. The prepared tungsten oxide quantum dot has the advantages of uniform size, easy dispersion and good fluorescence stability, and the fluorescence emission spectrum of the tungsten oxide quantum dot is dependent on excitation wavelength, so the tungsten oxide quantum dot is extensively applicable to biological imaging, biomarkers, light-emitting sensing element and other fields.

The invention discloses a dual-emission-ratio fluorescent carbon dot as well as a preparation method and application thereof. According to the preparation method of the dual-emission-ratio fluorescent carbon dots, sodium alginate and glutathione are subjected to hydrothermal carbonization or solvothermal carbonization to prepare the dual-emission-ratio fluorescent carbon dots. The method is simple and easy to operate, low in cost and good in repeatability. The excitation wavelength of the prepared carbon dots is 420 nm, and the dual emission wavelengths are 480 nm and 650 nm respectively. In addition, the dual-emission-ratio fluorescent carbon dots are high in light stability, good in water solubility, low in cytotoxicity, good in biocompatibility, capable of being used for specific detection of Fe 3+, good in selectivity and high in sensitivity; so that the fluorescent carbon dot can be used for sensitive detection of Fe 3+ in environmental water such as tap water.

The invention provides fluorescent nanoparticles and a preparation method thereof. The method comprises the following steps: step 1, encapsulating small molecules having fluorescent properties into pores of nanoparticles having a microporous structure; and step 2, performing a reaction on blocking molecules and the product obtained in the step 1 to obtain the fluorescent nanoparticles provided bythe invention, wherein the small molecules in the step 1 are negatively charged, and the nanoparticles are positively charged; and the blocking molecules have a molecular structure capable of blockingthe pores of the nanoparticles. According to the method provided by the invention, the obtained fluorescent nanoparticles have an average particle diameter of 100 +/- 5 nm, a specific surface area of1429 m<2>/g and a pore volume of 0.64 cm<3>/g; and the nano material has good fluorescence intensity stability, a quantum yield of 23.2%, and fluorescence lifetime of 1.9 ms, and is an ideal materialfor a biological fluorescent probe.

The invention provides a quantum dot fluorescence coded microsphere and a preparation method thereof. The preparation method comprises the following steps: respectively dissolving N kinds of quantum dots with different colors in a mixed solution formed by an oil-soluble monomer and a cross-linking agent to obtain N kinds of oil-phase mixtures, wherein N is greater than or equal to 2; sequentiallydispersing the N oil-phase mixtures into the same emulsifier solution according to the sequence that the wavelengths of the quantum dots dissolved in the N oil-phase mixtures are decreasing so as to form quantum dot micelles; adding the quantum dot micelles and an initiator into water, and carrying out a polymerization reaction under the protection of nitrogen to obtain quantum dot seed microspheres; adding a functional monomer into a polymerization reaction system, carrying out a grafting reaction on the quantum dot seed microspheres and the functional monomer, and carrying out purification treatment after the reaction is finished so as to obtain the quantum dot fluorescence coded microsphere.

The invention discloses a method for detecting fenpropathrin pesticides by a fluorescent nanometer cadmium selenide (CdSe) quantum dot probe. The fenpropathrin pesticides in a solution can be rapidly detected as fluorescence of fluorescent nanometer CdSe quantum dots can be quenched by fenpropathrin, a detection limit of the fenpropathrin pesticides can reach 2.5*10<-8>mol/L, and the correlation coefficient is 0.9997. The method disclosed by the invention is simple and convenient, high in sensitivity and high in selectivity, and further has the characteristics of high sensitivity and high selectivity in detecting fenpropathrin in mixed samples.

The invention discloses a preparation method of carbon quantum dots. The preparation method comprises steps as follows: a, municipal sludge is carbonized, and black powder is obtained; b, the black powder obtained in step a is uniformly dispersed in nitric acid, a mixed solution is obtained, wherein the mass fraction of nitric acid is 60%-68% and a mass ratio of the black powder to nitric acid is1:(100-400), the mixed solution is subjected to ultrasonic treatment for 20-260 min under 28-40 KHz, a solution I is obtained and then is subjected to heating reflux for 5-24 h at the temperature of 60-140 DEG C and cooled to room temperature, and a solution II is obtained; c, the solution II is filtered, and a filtrate is obtained; the filtrate is centrifuged for 15-60 min at revolving rate of 4,000-12,000 r/min, a supernatant is taken and dialyzed for 8-48 h, and an aqueous carbon quantum dot solution is obtained. The preparation method of the carbon quantum dots has beneficial effects thatthe carbon quantum dots have higher activity, contain functional groups such as carbonyl, hydroxyl, amino and the like and have higher silver light stability and a larger fluorescence range; the production cost is low, and the method is simple and has good economic benefit.

The invention discloses a method of synthesizing a rear earth Dy-doped CdTe:Dy quantum dot by a hydrothermal process. Operation steps of the preparation method are as follows: under protection of nitrogen gas, injecting pre-prepared sodium hydrogen telluride liquor into mixed liquor of pre-prepared cadmium salt, dysprosium oxide and a modifier water-soluble N-acetyl-L-cysteine; and then, placing the liquor into a hydrothermal reaction kettle for reacting and preparing the rear earth Dy-doped CdTe:Dy quantum dot which is adjustable in fluorescence emission wavelength and high in fluorescence quantum yield. The hydrothermal process has advantages of being low in operation cost, simple, convenient and safe to operate, green, environment-friendly, and the like. The obtained rear earth Dy-doped CdTe:Dy quantum dot has the advantages of being excellent in fluorescence performance, good in biocompatibility, low in toxicity, and the like, and can be used as a novel fluorescence nanoprobe for being widely applied to biochemical analysis and the biomedicine field.

The disclosed preparation method for a high-efficient green-light rare-earth compound film comprises: (1) preparing any one rare-earth terbium (III) compound of Tb(acac)3Phen, Tb(TFA)3Phen, Tb(HFA)3Phen and Tb(TTA)3Phen (acac, TFA, HFA, TTA, and Phen for acetylacetone, trifluoro acetylacetone, hexafluoro acetylacetone, thenoyl trifluoroacetone, and 1, 10-ortho-phenanthroline, respectively); (2) preparing functional aqueous phase, mixing the terbium (III) compound with one fatty acid for ultrathin film preparation on gas-liquid two-dimensional surface and the transfer toward hydrophobic solid substrate. This product has characteristic fluorescence-emission peak on 535.0-557.5nm, keeps layer periodic structure after 26 weeks to detect out the fluorescent signal, and shows important application.