171results about How to "Good fluorescence stability" patented technology

The invention discloses a near-infrared silver sulphide quantum dot as well as a preparation method and application thereof. The silver sulphide quantum dot has a monoclinic phase structure, the particle diameter of the silver sulphide quantum dot is below 8nm, and the surface of the silver sulphide quantum dot can be connected and modified with a hydrophilic group of hydrophilic reagent containing sulfydryl. The preparation method comprises the following steps: fully reacting a mixed reaction system containing silver source and long-chain mercaptan in a sealed environment; cooling the mixed reaction system, and then adding a polar solvent; carrying out centrifugation and wshing to obtain a hydrophobic near-infrared silver sulphide quantum dot; fully mixing the hydrophobic near-infrared silver sulphide quantum dot and hydrophilic reagent containing sulfydryl in organic solvent to react; and carrying out centrifugation and washing the reacting mixture to obtain the biocompatibility near-infrared silver sulphide quantum dot. The quantum dot disclosed by the invention has the advantages of high fluorescence yield, good fluorescence stability, good biocompatibility and even size, and can be used for biological tissue imaging; and the preparation technology has moderate condition, short period and good repeatability, is simple to operate and is easy to control.

The invention relates to magnetic fluorescent microspheres and a preparation method thereof. The particle size of the magnetic fluorescent microspheres is 5-10 mu m, the fluorescence excitation wavelength range is 400-700nm, and the fluorescence intensity is not reduced within 24h. The prepration method comprises the following steps: adding a swelling agent into monodisperse carboxylated polystyrene microspheres, and adding magnetic nano microparticles into a swelling system; shaking on a decolorization shaker for 12-48h; using mixed solution of cyclohexane and ethanol for cleaning sediment, and sequentially carrying out ultrasonic dispersion and centrifugal separation till supernatant liquid is colorless under an ultraviolet lamp; and saving a final sediment product in 1ml of liquor. Compared with the existing magnetic fluorescent microspheres, the magnetic fluorescent microspheres have the advantages of uniform and controllable diameter, good fluorescence stability, simple preparation process, multiple types of fluorescence codes and the like, and can not only carry out fast separation and purification on reactants by being applied in the biological macromolecular detection, but also simultaneously detect a plurality of target molecules in a sample to be detected in a reaction tube and a hole, thereby being widely applied in the fields of immunoassay, nucleic acid hybridization, genotype analysis and the like.

The invention discloses a magnetic fluorescent multimodal nano biological probe as well as a preparation method and application thereof. The magnetic fluorescent multimodal nano biological probe specifically targets a liver-cancer cell. According to the preparation method, magnetic nano particles and fluorescent dye are co-embedded in silicon dioxide; an amino group is functionally modified by the silicon dioxide; nucleic acid aptamer and a magnetic fluorescent probe are covalently coupled and synchronously specifically target the liver-cancer cell. The magnetic nano particles are paramagnetic iron oxides of which the sizes are ten nanometers; the fluorescent dye is fluorescein isothiocyanate; the embedding medium silicon dioxide is obtained through the hydrolysis of tetraethyl orthosilicate and 3-aminopropyltriethoxysilane; the nucleic acid aptamer is TLS11a. A synthetic method of the probe is simple and convenient; materials are easily obtained; fluorescence properties are stable; a foundation is laid for the early diagnosis of a liver cancer.

The invention relates to a method for preparing a Y2O3:Tb<3+>@SiO2-NH2 fluorescence sensor array used for detecting an organic chlorine pesticide. The marking recognition sites in the fluorescence sensor array are mutually effected with organic chlorine pesticide molecules (target molecules), the target molecules and Tb<3+> on the recognition sites form an organic ligand through coordination, and change of the fluorescence intensity of Tb<3+> is used for detecting the target molecules. The method comprises the following three steps: preparing Y2O3:Tb<3+> fluorescent powder, then synthesizing a Y2O3:Tb<3+>@SiO2-NH2 fluorescence probe having capability for identifying the marking target molecules, finally, through a micromachining technology and a plasma etching method, dropping the fluid suspension of the fluorescence probe having the capability for identifying the marking target molecules on a silicon chip, naturally drying the silicon chip, and spontaneously putting the fluorescence probe materials in a micro hole to obtain the fluorescence sensor array for high-selectivity identification and high sensitive signal detection on the target molecules.

The invention provides a preparation method of a highlight blue-green fluorescent water soluble silicon quantum dot. The highlight blue-green fluorescent water soluble silicon quantum dot is synthesized through one step at normal pressure by adopting a high boiling point water soluble reagent glycerol as a solvent and utilizing a microwave method. The preparation method of the highlight blue-green fluorescent water soluble silicon quantum dot comprises the following steps: adding sodium citrate into glycerol, and dissolving thoroughly; introducing Ar gas for removing oxygen in a solution, then adding 3-aminopropyl triethoxy silane, and continuously stirring while the Ar gas is introduced; transferring the solution into a microwave reactor, and reacting for 5-15 minutes at the temperature of 160-200 DEG C; adding the obtained silicon quantum dot solution into absolute ethyl alcohol, centrifuging, and reserving supernatant; and dialyzing the supernatant by adopting a dialysis bag, so as to obtain a pure silicon quantum dot solution, and carrying out freeze drying on the pure quantum dot solution for later use. The preparation method of the highlight blue-green fluorescent water soluble silicon quantum dot has the advantages that synthesis is realized through one step at normal pressure by adopting the microwave method, a synthetic process is simple and easy to operate, and the synthesized water soluble silicon quantum dot has the advantages of long emission wavelength, high luminous intensity, good fluorescent stability, low cytotoxicity and good biocompatibility.

The invention discloses fluorescent nanospheres, a preparation method thereof, and applications of the fluorescent nanospheres in the field of chemical sensing. The fluorescent nanospheres, which are fluorescent nanoprobes and are uniform in particle size distribution, are obtained via catalytic auto-polymerization of 3-aminophenylboronic acid in an aqueous solution at the presence of a catalyst, and via ultrafiltration processing. The fluorescent nanoprobes can be combined with adenosine monophosphate-modified oxidized grapheme so as to form a fluorescence resonance energy transfer system; when cis-dyhydroxy biological molecules are added into the fluorescence resonance energy transfer system, because of competition on boron affinity interaction, the fluorescent nanospheres and the adenosine monophosphate modified oxidized grapheme are separated, and combination of the fluorescent nanospheres with the cis-dyhydroxy biological molecules is realized, fluorescence of the fluorescent nanospheres is recovered, and in a certain concentration range, fluorescence intensity and the concentration of the cis-dyhydroxy biological molecules are in a linear relationship. Fluorescence properties of the fluorescent nanoprobes are stable, and are not easily influenced by environmental factors. The preparation method is simple; identification selectivity and capacity of resisting disturbance of the fluorescent nanoprobes are excellent.

The invention discloses a method for detecting the concentration of ferrohemoglobin by using a fluorescent carbon dot probe. The method comprises the following steps: 1, preparing different concentrations of fluorescent carbon dot-containing ferrohemoglobin standard solutions, detecting the fluorescence intensity of the standard solutions to obtain a standard solution fluorescence spectrogram, and establishing a linear relation between a difference between the fluorescence intensity of the standard solution with the ferrohemoglobin concentration being 0 and the fluorescence intensity of every standard solution and the ferrohemoglobin concentrations; and 2, preparing a fluorescent carbon dot-containing ferrohemoglobin sample solution, detecting the fluorescence intensity of the sample solution, and determining the concentration of ferrohemoglobin in the sample solution through the linear relation. The ferrohemoglobin concentration is detected by using the characteristics of a ferrohemoglobin quenching fluorescence carbon dot with the fluorescence carbon dot as a probe, so the method has the advantages of simple and convenient detection process, high sensitivity and low detection limit, and can realize online, in-situ, rapid and sensitive detection of the concentration of ferrohemoglobin in a practical sample.

The invention discloses a nickeliferous fluorescent quantum dot which is low in toxicity, has wide absorption spectrum and narrow fluorescence emission spectrum, and is adjustable in luminous color along with excitation wavelength, high in luminous efficiency, high in stability and applicable to construction of quantum dot-sensitized solar cells and LED devices. The nickeliferous fluorescent quantum dot comprises one of or combination of nickel selenide, nickel telluride and nickel sulfide, the quantum dot particle size ranges from 2nm to 20nm, the quantum yield is 10-60%, and the half-peak width of a photoluminescence spectrum is 30-130nm. Preferably, the NiSe fluorescent quantum dot is optimal when x=0.5.

The invention discloses a method for detecting potassium permanganate through graphene quantum dot fluorescence quenching. The method is characterized in that a graphene quantum dot probe is used as a fluorescence probe and by virtue of the characteristic that the fluorescence intensity of the graphene quantum dot probe weakens with the increasing of the concentration of a potassium permanganate solution, high-sensitivity detection is performed and the change value of the fluorescence intensity of the graphene quantum dot probe forms a good linear relationship with the concentration of the potassium permanganate, with the correlation coefficient of 0.991. The method is easy and convenient to operate, rapid in detection, high in sensitivity and good in selectivity, and can perform online in-situ rapid and sensitive detection on the potassium permanganate in a mixed sample.

The invention relates to a preparation method of a multifunctional dyed fluorescent cotton fabric based on MOF. The method includes the steps of preparing a pretreated Zn-MOF cotton fabric and preparing the multifunctional dyed fluorescent cotton fabric based on the Zn-MOF. The method is simple in process operation and high in efficiency and requires no special equipment, raw materials are low incost and easy to obtain, and the method is suitable for industrial production. The prepared multifunctional dyed fluorescent cotton fabric based on the Zn-MOF is excellent in fluorescent performance and meanwhile has the properties of resisting bacteria, preventing generation of stink, mold and moths, resisting ultraviolet rays, retarding inflaming and the like.

The invention belongs to the fluorescent sensing technical field and specifically relates to a high-efficiency organic fluorescent material and application of the material in TNT (trinitrotoluene) detection. The structural formula of the high-efficiency organic fluorescent material provided by the invention is Ar2-Ar1-Ar-Ar1-Ar2, wherein Ar1-Ar-Ar1 forms a light-emitting unit; the light-emitting center Ar can be spirofluorene, benzene, carbazole (alkyl chains different in length can be connected at No.9 site) or fluorene (alkyl chains different in length can be connected at No.9 site); Ar1 can be fluorene, biphenyl or difluorene; and electric-active unit Ar2 can be furan, pyrrole, thiophene, carbazole, diphenylamine or triphenylamine. An electro-polymeric thin film formed from the material through electrochemical polymerization is characterized in that intermolecular aggregation in the electrochemical polymerization process can be effectively reduced, the fluorescence efficiency of the electro-polymeric thin film is improved, and the electro-polymeric thin film is capable of effectively transferring charges with TNT molecules to quench fluorescent light, and therefore, effective detection on TNT is realized.

The invention discloses a method for detecting potassium dichromate by utilizing a graphene quantum dot probe. The method is characterized by comprising the following steps: (1) establishing a linear relationship: preparing a standard solution of graphene quantum dot and potassium dichromate solution, and obtaining the linear relation between the fluorescent intensity of the graphene quantum dot and the concentration of the potassium dichromate through the fluorescent spectra; (2) detecting: detecting the fluorescent intensity of the to-be-detected potassium dichromate solution, and determining the content of the potassium dichromate in the to-be-detected potassium dichromate solution according to the linear relation. The method is easy to operate, rapid in detection, high in sensitivity and good in selectivity, has the characteristics of high sensitivity and high selectivity when potassium dichromate in a mixed sample is detected and is promising in application prospect.

The invention discloses a fluorescent CdSe nanometer quantum dot probe for pesticide dimethoate, and application of the probe. A preparation method of the fluorescent CdSe nanometer quantum dot probe for pesticide dimethoate comprises the steps of preparing selenium stock solution; preparing cadmium stock solution; and preparing the fluorescent CdSe nanometer quantum dot probe for pesticide dimethoate. The probe has detection limit up to 1.5*10<-7> mol/L for pesticide dimethoate. The preparation method has the advantages of simple operation method, rapid detection, and high sensitivity and selectivity for dimethoate in a mixed sample.

The invention discloses a method for detecting potassium dichromate and ascorbic acid by using a graphene quantum dot probe. The method is characterized in that the graphene quantum dot probe is used as a fluorescence probe and by virtue of the characteristics that the fluorescence intensity of the graphene quantum dot probe weakens with the increasing of the concentration of a potassium dichromate solution and increases with the increasing of the concentration of an ascorbic acid solution, high-sensitivity detection is performed and the change value of the fluorescence intensity of the graphene quantum dot probe forms a good linear relationship with both the concentration of the potassium dichromate and the concentration of the ascorbic acid, with the correlation coefficients of 0.994 and 0.996 respectively. The method is easy and convenient to operate, rapid in detection, high in sensitivity and good in selectivity, and can perform online in-situ rapid and sensitive detection on the potassium dichromate and the ascorbic acid in a mixed sample.

The invention provides a preparation method and application of fungal hypha nitrogen and sulfur self-doped carbon dots and belongs to the field of researches of fluorescent carbon nano-materials. Thepreparation method comprises the following preparation steps: (1) firstly, preparing fungal hyphae by utilizing a biosynthesis technology; culturing the hyphae in a PDA (Potato Dextrose Agar) solid culture medium at constant temperature; then inoculating the hyphae into a modified PDA liquid culture medium and culturing in a constant-temperature oscillator; finally, purifying the hyphae; and (2) taking the hyphae as a raw material and synthesizing the nitrogen and sulfur self-doped carbon dots (N,S-CDs) in one step under a hydrothermal condition. According to the preparation method provided bythe invention, a method combining biosynthesis and the hydrothermal condition is adopted for the first time, and the N,S-CDs with excellent performance are prepared. The N,S-CDs can be used for carrying out high-selectivity and high-sensitivity detection on tetracycline antibiotics (TCs); and when the concentration of TC is 0.5 to 38.46muM, the linear correlation coefficient is 0.991 and the TC detection limit is 0.041muM. The N,S-CDs are used for preparing fluorescence detection test paper and the fluorescence detection test paper can be used for rapidly detecting the TCs in culture wastewater. The N,S-CDs do not influence the survival rate of cells and have a very great application potential in the field of cell imaging.

The invention discloses a preparation method of a hydroxyl modified metal organic framework material fluorescent probe, and fluoride detection application of the fluorescent probe, and belongs to thetechnical field of fluorescent sensing. A hydroxyl modified metal organic framework material (MIL-53(Al)-OH) is prepared by taking aluminium nitrate hexahydrate as a metal salt ligand and 2,5-dihydroxyterephthalic acid as an organic ligand in an N,N-dimethylformamide solvent through solvothermal reaction. The material is ultrasonically dispersed in Tris-HCl buffer solution, so that the fluorescentprobe MIL-53(Al)-OH-Tris can be prepared; under the 365 nm excitation wavelength, the MIL-53(Al)-OH-Tris fluorescent probe has a strong fluorescence emission peak at 515 nm; and thus, the fluorescentprobe can be used for sensitive detection of fluoride ions.

The invention discloses a preparation method of a copper nanocluster self-assembly and application of the copper nanocluster self-assembly as a fluorescent probe to detection of histamine. 2,3,5,6-tetrafluorothiophenol serves as a ligand and a reductant to synthesize the banded copper nanocluster self-assembly with orange fluorescence in one step. The preparation method is a novel method for preparing the copper nanocluster self-assembly and has the advantages of being simple to operate, quick in preparation and low in cost. The synthesized copper nanocluster self-assembly has the advantages of broad excitation spectrum, narrow emission spectrum, high fluorescence quantum yield, strong fluorescence stability and the like, and besides, can be used for detecting histamine.