63results about How to "Strong resistance to photobleaching" patented technology

The invention relates to a preparation method and an application of a magnetic fluorescent nanoparticle with a shell-core structure. Firstly, a silica magnetic microsphere with a shell-core structure is prepared by using one or more than one of nanoparticles of Fe3O4, gamma-Fe2O3, MeFe2O4 (Me=Co, Mn, Ni), metal Ni, Co, Fe, and alloy Fe-Co, Ni-Fe as the inner core, and coating a silica shell, and then a fluorescent material (a chelate of Eu3+, Sm3+, Dy3+, Tb3+ and the like) is absorbed on the silica shell. Then, a layer of silica is coated on the surface to improve the stability of the fluorescent magnetic microsphere, and to prevent agglomeration and fluorescent material leakage. A lot of rare earth fluorescent materials are wrapped in the shell layer, so the fluorescence intensity signal of a prepared sample is greatly increased. The nanoparticle has dual functions of enrichment and marking, and has wider application prospects in the biomedical field.

The invention belongs to the field of preparation of fluorescent carbon dots, and discloses a synthesis method of the fluorescent carbon dot with an up-down conversion function. The method comprises the following steps of: adding chilli flakes into water and evenly mixing, thereby obtaining a mixture; transferring the mixture into a hydrothermal kettle, performing a hydrothermal treatment at 120 to 200 DEG C for 2 to 10 hours, and cooling and filtering, thereby obtaining a brown liquid; centrifuging the brown liquid for 10 to 20 minutes, thereby obtaining a supernatant; dialyzing the supernatant by using a dialysis bag with the flow interception volume of 3500; and collecting a dialysate after dialyzing for 10 to 30 hours, thereby obtaining the fluorescent carbon dot. By taking a cheap raw material as a carbon source and the water as a solvent, the method for synthesizing the fluorescent carbon dot with the up-down conversion function in an environmental-friendly manner has the effects that the process is simple; the pretreatment operation is not required; the process that the synthesis is assisted by a strong acid or a surface passivator is not required; the raw material is cheap and easy to obtain; the synthesis condition is moderate and controllable; the high fluorescence quantum yield is achieved; and the carbon dot is good in fluorescent bleaching resistance and stability.

The invention relates to a fluorescence detection method and provides a fluorescent probe which has high sensitivity and high selectivity and is used for detecting intracellular hypochloric acid and an application of thiospirolactone in intracellular hypochloric acid detection. The structure of the fluorescent probe for detecting the intracellular hypochloric acid is a triphenylmethane fluorescent probe with a Xanthone ring parent structure; and the fluorescent probes of the thiospirolactone all adopt corresponding spirolactones as raw materials. The thiospirolactone has high-sensitivity fluorescent response characteristics on hypochloric acid, and when being used in the fluorescent probe for detecting the intracellular hypochloric acid, the selectivity is high. The probe has strong lightstability, no illumination self oxidation, rapid response to an aimed compound, good cell permeability and no strong cytotoxicity, and a product formed by combining the fluorescent probe and the aimed compound has strong photobleaching resistance. The thiospirolactone used for detecting the hypochloric acid of the aimed compound has high sensitivity and strong specificity and other active oxygen in cells has no interference on the detection.

The invention provides a conjugated polymer containing fluorene as well as a preparation method and an application thereof. 2, 5-dibromophenol is used as a raw material to react with tetraglycol substituting methyl benzol sulfonyl to obtain long-chain alkoxy substituted paradibromobenzene (monomer I); 2, 7-dibromofluorene is used as a raw material to react with bromo-triglycol monomethyl ether to be esterified by virtue of boric acid to obtain alkoxy-decorated fluorene borate (monomer II); the monomer I and the monomer II are under Suzuki coupled reaction to obtain the conjugated polymer containing the fluorene. The preparation method of the conjugated polymer is simple to operate and moderate in reaction condition. The conjugated polymer containing the fluorene can be used for manufacturing dyeing reagent of cancer cells, has characteristics of small biological toxicity, good cell compatibility and good light stability and has good application value in the field of a biological dyeing material.

The invention relates to the technical field of organic synthesis and novel materials and particularly relates to a near-infrared fluorescent compound with AIE performance as well as a preparation method and application thereof. According to the fluorescent compound, indole salts are used as receptors; a pyrrole donor and donors introduced with different conjugated structures in a site 2 and a site 5 of pyrrole are used for effectively regulating and controlling fluorescence emission of molecules; groups in a site 1, the site 2 and the site 5 are used for forming certain distortion with a pyrrole ring, so that the AIE performance is given to the compound; because of D-Pi-A actions in the molecules, the molecules can achieve long-wave-band light emission; the light emission wavelength is between 600 and 750nm and has greater Stokes shift. According to the fluorescent compound, the indole salts are used as targeting groups; the fluorescent compound is capable of achieving targeting imaging of mitochondria in various cells, has the advantages of washing-free property, low biotoxicity and high photobleaching resistance and the like in the imaging process, and is also capable of monitoring dyeing of the mitochondria in real time.

The invention discloses fluorescent SiNDs (silicon nanodots). The fluorescent SiNDs are prepared from silane and Bengal rose with a hydrothermal method through one step. Compared with the prior art, the prepared SiNDs have ultrahigh fluorescent quantum yield (100%) and can realize long-time specific imaging of mammal cytolysosome. Besides, the imaging effect of lysosome of the SiNDs is not affected by cell cleaning, immobilization, permeabilization and the like and the fluorescent SiNDs have the advantages of cleaning resistance, immobilization resistance and permeabilization resistance. Meanwhile, the SiNDs also have the advantages of low preparation cost, simple synthesis method, good water dispersity, narrow fluorescent emission peak width, good photostability, good cytocompatibility, low photocytotoxicity and the like and are expected to become novel lysosome fluorescent probes.

The invention provides water-soluble red/green light double-emission carbon dots (RGDE CDs) which are prepared by taking 2,5-diaminotoluene sulfate as a carbon source through a one-step method. Compared with an existing method, a multi-step material preparation process is avoided. The RGDE CDs prepared by the method have excellent anti-photo-bleaching capability, good biocompatibility and low cytotoxicity. Under the single excitation wavelength, the strength of green fluorescence (with the wavelength of 525nm) of the RGDE CDs is quenched after OONO- is added, and the strength of red fluorescence (with the wavelength of 603nm) is basically not changed. On the basis, the invention establishes a novel method for determining fluorescence of the OONO- through a ratio method.

The invention belongs to the technical field of nucleic acid detection and relates to a nanoprobe for real-time parallel detection of content of various mRNA in living cells. The nanoprobe comprises a penetrating peptide, a quantum dot, capture probes, reporter probes and gold nanoparticles. The quantum dot serving as a donor is connected with the capture probes; the gold nanoparticles serving as a receptor is connected with the reporter probes; the capture probes and the reporter probes are in complementary pairing by means of a part of basic groups to form energy transfer donor-and-receptor pairs; the penetrating peptide is connected with the quantum dot to modify the energy transfer donor-and-receptor pairs; the capture probes can be in complementary pairing completely with a target mRNA. The nanoprobe is capable of entering the cells effectively and high in photobleaching resistance. Various nanoprobes are introduced into the living cells to realize real-time parallel detection of content of various mRNA in the living cells; thus, comprehensive understanding on expression levels of different genes in the cells and interaction between the different genes is guaranteed.

The invention provides a fluorescent probe with functions of detecting hydrogen peroxide and performing photodynamic killing on cancer cell activity as well as a preparation method and application thereof, and belongs to the technical field of a biochemical material. The fluorescent probe with the functions of detecting hydrogen peroxide and performing photodynamic killing on cancer cell activityhas aggregation induced luminescence characteristic, can specifically respond to the hydrogen peroxide, generates a substance with stronger fluorescence, can be applied to detection on the hydrogen peroxide in cells, and can selectively position subcellular organelle lipid droplets in the cells; the product obtained through action between the fluorescent probe and the hydrogen peroxide has large stokes displacement, so self-absorption can be avoided and background interference can be reduced; the fluorescent probe as well as the product obtained through the action between the fluorescent probeand the hydrogen peroxide have high light stability and photobleaching resistance, and are suitable for long-time tracing of the hydrogen peroxide in living cells or living bodies; meanwhile, the product obtained through the action between the fluorescent probe and the hydrogen peroxide has active oxygen generation capacity, can be applied to photodynamic killing of the cancer cells and can construct a diagnosis and treatment reagent integrating diagnosis and treatment functions.

The invention provides fluorescent gold nano-clusters with arginine oligomers as surface modification and a preparation method of the fluorescent gold nano-clusters, an active oxygen detection method based on the fluorescent gold nano-clusters and a kit containing the fluorescent gold nano-clusters, as well as applications of the fluorescent gold nano-clusters and the combined product. The fluorescent gold nano-clusters have the advantages of high photobleaching resistance, light scintillation resistance, and good biological compatibility. The active oxygen detection method has the characteristics of simple method, and mild reaction conditions, such as normal temperature and normal pressure, water phase and pH neutral vicinity; and the method is good for biological applications of the fluorescent gold nano-clusters.

The invention discloses a method for determining ultratrace oleylamine grafted polysuccinimide based on a carbon dot marked fluorometric immunosorbent method. The method comprises the following steps:preparing PSIOAm coating antigen and immunogen, injecting the immunogen into an animal body to obtain a high-specificity antibody, then preparing C-dots marked PSIOAm antibody into a fluorescent antibody, and then establishing carbon dot fluorometric immunosorbent to accurately determine the content of PSIOAm. By combining the specificity of the antigen and antibody reaction and the carbon dot with high fluorescent quantum yield, the PSIOAm nano particles are quantitatively detected and analyzed. A linear range of the detection method is 5*10<-4> to 5*10<2>ng/mL, and the detection limit can reach 0.15 pg/mL.

The invention discloses a cell nucleolus imaging red fluorescent carbon dot and a preparation method and application thereof. The red fluorescent carbon dot is prepared from the following raw materials in parts by weight: 1 part of Congo red and 1-10 parts of p-phenylenediamine. The fluorescent carbon dot is prepared by taking p-phenylenediamine and Congo red as raw materials and adopting a one-step hydrothermal method, and the carbon dot prepared by the invention can realize rapid, no-clean, long-time and light-stable (anti-bleaching) imaging of cell nucleuses and nucleuses of mammalian cells, and can also be applied to living cell nucleolus fluorescence imaging of model animals (such as zebra fish and nematodes). In addition, the carbon dot also has the advantages of low preparation cost, good water dispersibility, low cytotoxicity, large Stokes shift and the like, and can replace the commercialized nucleolus fluorescent probe which is widely used at present.

The invention relates to a quantum dot immunochromatography detection card and method for detecting sulindac through a tertiary system competitive immunoassay process. The detection card comprises a substrate, a detection antigen release pad, a quantum dot probe release pad, a chromatography film and a water absorbing pad, the detection antigen release pad contains detection antigen formed by coupling of ovalbumin and naproxen, the quantum dot probe release pad comprises a quantum dot probe marked with anti-ovalbumin antibody, the chromatography film is provided with a detection line and a quality control line, the detection line fixes anti-naproxen antibody, and the quality control line fixes ovalbumin antigen. The detection antigen is dissolved in a detection system from the release pad,the detection antigen, detection antibody and marking antibody form a tertiary system immune compound, and fluorescent detection signals are generated. Under detection reference action of the qualitycontrol line, whether samples contain sulindac or not is judged according to fluorescent signals on the detection line, so that signal intensity and stability of detection are improved, and detectionsensitivity and quantification accuracy are improved.

The invention provides a near-infrared silicon-based rhodamine fluorescent dye, a preparation method and application of the near-infrared silicon-based rhodamine fluorescent dye in mitochondrialmeninges in-situ wash-free imaging. The structural formula of the near-infrared silicon-based rhodamine fluorescent dye is shown as a formula (I). The near-infrared silicon-based rhodamine fluorescent dye disclosed by the invention is few in synthesis steps, simple in preparation method and high in yield, and the obtained near-infrared silicon-based rhodamine fluorescent dye is good in ultraviolet absorption intensity, high in fluorescence quantum yield, small in biological autofluorescence interference, low in biotoxicity, relatively good in biocompatibility, high in photobleaching resistance and capable of continuously imaging for a long time, and can be used for mitochondrial meninges in-situ wash-free fluorescence imaging.

The invention discloses a sensor based on singlet oxygen channel light-emitting quantum dots. The sensor comprises quantum dot nano hydrosol and functional photosensitive microspheres; the quantum dot nano hydrosol modifies the fat-soluble quantum dots with the emission wavelength being 520-620 nm to the water-soluble quantum dots;` the water-soluble quantum dots and a thiazine compound are coated by nano latex spheres which are modified by carboxyl, amino, hydroxyl, aldehyde group or sulfo group to prepare the quantum dot nano latex spheres; surface of the quantum dot nano latex spheres is modified with glucan gel to obtain the quantum dot nano hydrosol; the functional photosensitive microspheres are characterized in that a photosensitive material phthalocyanine compound is coated by the nano latex spheres which are modified by carboxyl, amino, hydroxyl, aldehyde group or sulfo group, and the functional photosensitive microspheres can be obtained. The sensor is a novel homogeneous fluoroimmunoassay sensor based on the singlet oxygen transmission, a one-to-one mode of a traditional energy ligand is changed, and a break through is provided to the space detection distance with 20 nm.

The invention discloses a kit, a probe and a method for rapid and sensitive detection of ofloxacin. The kit comprises a nano magnetic bead-nucleic acid aptamer probe, an RCA primer, an RCA template, aT4 DNA ligase, a Phi29 DNA polymerase and a NaYF4: Ce/Tb-cDNA time-resolved fluorescent probe. Fe3O4 nano magnetic beads are used as a rapid magnetic separation carrier, a nucleic acid aptamer specifically combined with ofloxacin is used as a recognition element, a nucleic acid signal is amplified through a rolling circle amplification technology, and time-resolved fluorescence is used as a signal source so that a novel technology for specific rapid sensitive detection of residual antibiotic ofloxacin in food is constructed. The method is short in detection period without depending on the chromatographic instrument and high in sensitivity and is as low as pmol/L in detection limit and quantification limit and is suitable for detection personnel in the market or enterprises.

The invention discloses a preparation method for a green-fluorescence carbon quantum dot. The preparation method comprises the following steps: weighing o-phenylenediamine, thiourea and ethanol, carrying out mixing, and carrying out a hydrothermal reaction; after completion of the reaction, transferring a product into a container for rotary evaporation until a liquid is completely evaporated so as to reserve a black residue on the wall of the container; then adding distilled water into the container, and allowing the black residue on the wall of the container to be dissolved in the distilled water so as to obtain a residue solution; and centrifuging the residue solution, and after completion of centrifuging, filtering a supernatant so as to obtain the green-fluorescence carbon quantum dot. The green-fluorescence o-phenylenediamine carbon quantum dot prepared by using the hydrothermal method provided by the invention can effectively detect NO.

The invention relates to a diclofenac quantum dot immunochromatography detection card and detection method based on a signal amplification system. The detection card comprises a lining plate, a detection antigen release pad, a quantum dot probe release pad, a chromatography film and a water absorption pad, wherein the detection antigen release pad contains detection antigens formed by coupling ovalbumin and diclofenac; the quantum dot probe release pad comprises a quantum dot probe labeled with anti-ovalbumin antibodies; the chromatography film is provided with a detection line and a quality control line; the detection line is fixed with anti-diclofenac antibodies; the quality control line is fixed with ovalbumin antigens; the detection antigens are dissolved into the detection system fromthe release pad; a ternary system immune complex is formed with the detection antibodies and marking antibodies; fluorescence detection signals are generated. Under the detection reference effects ofthe quality control line, whether the sample contains the diclofenac or not is judged according to the fluorescence signal on the detection line; the detected signal intensity and stability can be enhanced; the detection sensitivity and the quantity precision are improved.

The invention relates to a quantum-dot immunochromatography detection card and detection method for detecting tadalafil medicine with a ternary-system immune competition method. The detection card comprises a liner plate, a detection antigen releasing pad, a quantum-dot probe releasing pad, a chromatography film and a water absorption pad; the detection antigen releasing pad comprises a detectionantigen formed by coupling albumin eggs and the tadalafil medicine; the quantum-dot probe releasing pad comprises a quantum dot probe marked with an anti-albumin-egg antibody; the chromatography filmis provided with a detection line and a quality control line, the detection line fixes the antibody of the tadalafil medicine, and the quality control line fixes the albumin-egg antigen. The detectionantigen is dissolved into a detection system from the releasing pad, a ternary-system immune complex is formed by the detection antigen, the detection antibody and the marked antibody, and fluorescence detection signals are generated. Under the detection reference effect of the quality control line, whether the tadalafil medicine is contained in a sample or not is judged according to the fluorescence signals on the detection line, the signal strength and the stability of detection are improved, and the detection sensitivity and the quantitative accuracy are increased.

The invention relates to the field of molecular biology and microbiology, and discloses a fluorescent screening vector, the construction and application thereof. Polynucleotide and/or a complementary strand of the polynucleotide which encodes an enhanced green fluorescent protein are taken as a positive clone selection marker of the fluorescent screening vector; and an amino acid sequence of the enhanced green fluorescent protein is SEQ ID NO.5. The vector can be widely applied to the screening of positive clone in gene clone.