46results about How to "Fluorescent properties are stable" patented technology

The invention and belongs to the technical field of fluorescent nanomaterials, aims to solve the problems of relatively low yield of the current fluorescent carbon quantum dots, poor sensitivity of recognition response and anti-interference ability, a complicated reaction condition and the like, and provides a preparation method and application of fluorescent carbon quantum dots. With corn and dimethylene triamine DETA as raw materials, the fluorescent carbon quantum dots are synthesized in one step by a microwave heating method. The raw materials are cheap and easy to obtain; the carbon pointpreparation process method is simple and environmentally friendly; the fluorescent carbon quantum dots can be synthesized in large quantities; the fluorescent carbon quantum dots have small particlesizes of 3-5nm and uniform sizes, and can be stably dispersed in water, without an agglomeration phenomenon; the fluorescent carbon quantum dots have excellent fluorescence properties and relatively high fluorescent quantum yield; the fluorescent carbon quantum dots have excellent stability, and has stable performance under different ion concentrations, pH values and light irradiation time; the fluorescent carbon quantum dots have high selectivity, good reproducibility and high sensitivity during Cr (VI) and AA detection, and can quickly and accurately detect the contents of Cr (VI) and AA inliquid to be detected.

The invention discloses a rare-earth carbon nanoparticle, a preparation method of the rare-earth carbon nanoparticle and application for determining a pH value based on a fluorescence color scale. Therare-earth carbon nanoparticle disclosed by the invention is a fluorescent nanoparticle formed by carrying out a one-pot hydrothermal reaction among rare-earth europium ion, terbium ion as well as 2,6-dipicolinic acid and polyethylene glycol 400. The fluorescence color scale principle of the rare-earth ions is changed to indicate the pH value by utilizing the enhanced luminescence effect of carbon dots and protonation of the 2,6-dipicolinic acid. The rare-earth carbon nanoparticle disclosed by the invention can give out light to indicate the pH value in the aqueous solution and / or cells, hasexcellent fluorescence in the aqueous solution, high pH determination sensitivity and fast pH response, and have advantages to determination of the pH value of a biological sample with excellent fluorescence background. Compared with the general visual colorimetry according to the fluorescence color scale, the method for determining the pH value based on the fluorescence color scale is accurate.

The invention discloses a trace MUC1 fluorescence detection method based on the chained hybridization reaction and fluorescence carbon quantum dots. The method comprises the steps that carbon quantumdots are synthesized, neck ring DNA H1 and H2 are modified to the carbon quantum dots, and the carbon quantum dots are mixed with graphene oxide; when MUC1 does not exist, the carbon quantum dots modified with H1 and H2 are adsorbed to the surface of the graphene oxide, and because of the fluorescence resonance energy transfer effect, fluorescence quenching happens to the carbon quantum dots; whenMUC1 exists, MUC1 is combined with aptamer, chained hybridization reaction is promoted to happen to H1 and H2 to form chained hybrid products, H1 and H2 get away from the surface of graphene, and finally, the carbon quantum dots recover fluorescence; and then, the content of MUC1 can be determined through fluorescence detection. According to the trace MUC1 fluorescence detection method based on the chained hybridization reaction and fluorescence carbon quantum dots, signal amplification is achieved through chained hybridization reaction, the sensitivity of MUC1 detection is greatly improved;and furthermore, the fluorescent carbon quantum dots are stable in fluorescence property, and the stability and the repeatability of the method are greatly improved.

The invention discloses carbon dots, a preparation method thereof and application of the carbon dots in hypochlorite detection. The preparation method of the carbon dots comprises the following steps: respectively weighing 0.1-1 g of 2,4-difluorobenzoic acid, 0.5-2.5 g of glycine and 0.1-0.5 g of melamine for later use; putting the weighed chemicals into a reaction kettle filled with ultrapure water and absolute ethyl alcohol, and uniformly stirring and mixing; heating the reaction kettle at 120-200 DEG C for 6-48 hours, and then cooling the reaction kettle to room temperature; and adding the obtained brown solution into a dialysis bag, putting the dialysis bag into ultrapure water, and dialyzing to remove impurities so as to obtain a light yellow carbon dot solution. The carbon dots prepared by the hydrothermal method in one step have high fluorescence quantum yield and stable fluorescence property, and are non-toxic. Detection experiments show that the prepared carbon dots can be used as a fluorescent probe for quantitative detection of CIO<->, and are expected to become a commercial fluorescent probe for CIO<-> detection.

The invention discloses a preparation and characteristic of functional fluorescent carbon nanoparticles (referred to as CNPs) and an application thereof in bio-detection techniques. The preparation is characterized in that 1g of sodium alginate and 0.1g of NaOH are mixed and slowly added to 30ml of deionized water and thoroughly stirred and then placed in an autoclave and reacted for 4h at 160 DEG C. The carbon nanoparticles obtained by the reaction are subjected to acid-base neutralization. The nanoparticles have rich source of raw materials, cheap and easily available raw materials, and simple preparation method; synthesized carbon nanoparticles have good fluorescence properties including fluorescent stability, no light flashes, controllable excitation and emission wavelength, good biocompatibility, low toxicity, very small molecular weight and particle size, and have rapid development in biological detection, sensing, angiography, and many other application fields.

The invention provides a green synthesis method of a germanium quantum dot in a solution, a germanium quantum dot and application thereof in biological imaging. The green synthesis method comprises the following step: by taking germanium dioxide as a germanium source, polyvinylpyrrolidone as a protective agent and sodium borohydride as a reducing agent, preparing to obtain the germanium quantum dot. According to the invention, the used raw materials are simple, accessible and stable in property, and basically has no biological toxicity; high temperature and protection of inert gas are not required in the reaction process, thereby ensuring that the green synthesis method is simple and easy to operate; the prepared germanium quantum dot having blue fluorescence has a quantum yield of 26% or above, can be easily separated from the system, has no cytotoxicity and can be well used in biological cell imaging.

The invention provides an establishment method based on a surface plasma reinforcing energy transferring biosensor. The establishment method comprises the following steps of: 1) preparing a fluorescent gold nanoparticle cluster wrapped with protein; 2) preparing the gold nanoparticle modified by mercaptoethylamine; and 3) establishing an experiment system based on the surface plasma reinforcing energy transferring biosensor. The establishment method based on the surface plasma reinforcing energy transferring biosensor provided by the invention has the advantages that the fluorescent gold nanoparticle cluster wrapped with the protein and the gold nanoparticle modified by mercaptoethylamine are introduced to be served as the donor and the receptor for energy transferring; the concept of surface plasma reinforcing energy transfer is utilized to achieve quick, accurate, high-sensitivity and high-selectivity quantifying of the object liquaemin; synthesizing of the nanometer material in the method is simple in steps, removes harsh equipment and condition, is safe, simple and convenient to operate, low in toxicity, and low in cost; and the used synthesizing and detecting instrument and equipment are common equipment; and a reaction condition is simple; and the reaction can be simply carried out at a room temperature of water bath at 37 DEG C.

The invention discloses a pair of isomers, and a preparation method and application thereof, and the chemical structures of the pair of isomers are shown as formulas (I) and (II): the preparation method comprises the following steps: mixing (E)-2-(2-(Z)-1, 3, 3-trimethylindole-2-ethylene) ethylene) furan [2, 3-b] quinoline-3, 4 (2H, 9H)-diketone, diethyl sulfate, anhydrous potassium carbonate andan organic solvent, performing heating and reacting, concentrating an organic phase, and performing separating to obtain a product. According to the invention, two compounds are prepared by adopting aone-pot method, and the small organic molecule (I) can realize positioning and fluorescence response to lipid droplets in cells, and has the advantages of high sensitivity, rapid response, high specificity and the like; the small organic molecule (II) has fluorescence response to solution viscosity, can be used for detecting system viscosity, has strong acetylcholin esterase inhibition activity and can be used for treating related diseases.

The invention belongs to the field of rapid food safety detection, and relates to a method for preparing a fluorescently-coded microsphere test strip for simultaneous detection of multiple staphylococcal enterotoxins, and the method comprises the following steps of firstly preparing two fluorescent carbon quantum dots with good fluorescent characteristics, good water solubility and good biocompatibility, and preparing a series of fluorescently-coded microspheres with different fluorescence characteristics by adjusting the doping ratio of the two carbon quantum dots; fluorescently coding microspheres by the carbon quantum dots, and correspondingly labeling the antibody of enterotoxins to obtain a plurality of fluorescent antibody probes; finally dissolving the plurality of fluorescent antibody probes in a phosphate buffer solution containing sucrose and Tween 20 at equal quality to obtain a mixed solution containing the plurality of fluorescent antibody probes; and evenly spraying the mixed solution onto the glass fiber membrane as a bonding pad to prepare the fluorescent microsphere immunochromatographic test strip, so as to realize the simultaneous qualitative and quantitative detection of multiple enterotoxins. The method provided by the invention can improve the detection efficiency and accuracy and achieve rapid detection of mass food samples.

The invention belongs to the technical field of preparation of carbon quantum dot materials, and relates to a preparation method for solid-state carbon quantum dots. The preparation method comprises the following steps: firstly, mixing an ionic liquid with nitrile substances, and putting the mixture, as an electrolytic solution, into an electrolytic tank; respectively selecting two platinum electrodes, of which the area is no smaller than 1.0 cm<2>, as an anode and a cathode, and putting the anode and the cathode into the electrolytic tank, and switching on a power supply to react, thereby obtaining a light brown solution mixed with solid-state substances; then, carrying out suction filtration on the light brown solution mixed with the solid-state substances, carrying out vacuum-drying on the solid substances obtained by suction filtration, and transferring the solid substances into a clean container vessel, thereby obtaining the solid-state carbon quantum dots. The preparation method is simple in preparation process, convenient in operation, accessible in principle, and low in cost; the prepared solid-state carbon quantum dots are good in water solubility, stable in fluorescent property, and easy to store and transport.

The invention relates to a germanium fluorescent cluster, a preparation method of the germanium fluorescent cluster in aqueous solution and its application in biological imaging. The synthesis method uses germanium dioxide as germanium source, biomolecular cysteine ​​as protective agent, and sodium borohydride as reducing agent to prepare monomolecular-layer protected germanium nanoclusters with fluorescent properties. The raw materials used in the present invention are simple, easy to obtain, stable in nature, and non-toxic; the reaction process does not require the protection of high temperature and inert gas, and is simple and easy to operate; the obtained germanium quantum dots with emerald green or yellow fluorescence are in phase with the previously reported noble metal nanoclusters. It has a higher fluorescence quantum yield, and the cluster size is about 1nm. It has good water solubility and no cytotoxicity, and can be well applied to biological cell imaging.

The invention provides a fluorescent nanoparticle and a preparation method thereof, the method comprising: encapsulating a small molecule with fluorescent properties into the nanoparticle channel with a microporous structure; step 2: reacting the blocking molecule with the product obtained in step 1 The fluorescent nanoparticles of the present invention are obtained; wherein, the small molecules in step 1 are negatively charged, and the nanoparticles are positively charged; the blocking molecule is a molecular structure capable of blocking the pores of the nanoparticles. The average particle size of the obtained fluorescent nanoparticles is 100±5nm, and the specific surface area is 1429m 2 g ‑1 , the pore volume is 0.64cm 3 g ‑1 . The fluorescence intensity of the nanometer material has good stability, the quantum yield can reach 23.2%, and the fluorescence lifetime can reach 1.9ms, so it is an ideal material as a biological fluorescent probe.

The invention provides a method and product for preparing autofluorescence polystyrene material, which is characterized in that on the surface of polystyrene material, especially on the surface of polystyrene microspheres, it is acylated by Friedel-Crafts under the action of an acidic catalyst (Alkylation) reaction introduces small molecule color-producing (color-aiding) functional groups, which form π-π (p-π) conjugation with the large π bond of the benzene ring to form a conjugated system, which undergoes electronic transition under the action of excitation light Produce fluorescence. Under the excitation of 405nm laser, the prepared polystyrene fluorescent microspheres can produce obvious fluorescent signals in the blue, green and orange channels of the laser confocal microscope. At the same time, we found that the introduction of electron-withdrawing groups on the conjugated substituents can red-shift the emission peak of polystyrene materials. The preparation method of the invention is simple, high in efficiency and low in cost. The prepared autofluorescent polystyrene microspheres have the characteristics of high fluorescence intensity, stable chemical properties, no fluorescence leakage, high mechanical strength, etc., and have great application potential in the fields of biomedicine and electronic light-emitting devices.

The invention discloses a precious metal / phenolic resin core-shell structure biocompatible material and the preparation method and is characterized in that phenol, hexamethylenetetramine and the salt solution of precious metal are reacted for 2 to 10 hours at 120 to 180 DEG C so as to obtain a core-shell structure particle; and then the core-shell structure particle is used as the carrier and reacted for 5min-10h at 160-200 DEG C through the method of synthesizing magnetic nano-Fe3O4 to synthesize a three-tier core-shell structure particle containing Fe3O4 modified precious metal / phenolic resin / Fe3O4, or synthesize a four-tier core-shell structure material particle containing gold nano-particle modified precious metal / phenolic resin / Fe3O4 / Au. The material has fluorescent and magnetic dualfunctions and has good application prospect in biological fluorescence imaging or magnetic resonance imaging technology in living biological organisms or cells. The preparation method of the invention can easily obtain the raw materials and has simple technology and easy operation, which is suitable for industrialization amplification.

According to the cyclic amidinyl fluorescent molecule with the same-side push-pull electron effect described in the present invention, the structural formula of the fluorescent molecule is: the cyclic amidinyl fluorescent molecule contains both an electron-pushing group (EDG) and an electron-withdrawing group (EWG). ), thereby constructing a novel skeleton molecule with a 10π electron structure, in which the electron-pushing group and the electron-withdrawing group are on the same side of the π electron, and this structure has a large Stokes shift (approximately 100nm), excellent acid-base stability, and stable fluorescent properties in the pH range of 2.8-11.4. At the same time, the fluorescent molecule has no obvious cytotoxicity and has broad biological application prospects. A preparation method of the fluorescent molecule is also disclosed. The method has simple process, mild conditions and is suitable for industrial batch production.

The invention discloses a method for measuring cellular oxidative stress damages under ionizing radiation by using fluorescent protein as a fluorescence probe. The content of free radicals generated in ionizing radiation is quantitatively measured by using the fluorescent protein which is selectively positioned and expressed on a subcellular structure sensitive to the ionizing radiation, so that the damages of the ionizing radiation on the specific positions of a cell are speculated by directly observing the fluorescence intensity change of the protein. By the method, the emitted fluorescence is easy to detect, has high sensitivity, stable fluorescence properties, can normally emit light in a wider pH range, has higher resistance to high temperatures, detergents, salt, organic solvents and most ordinary enzymes, is not toxic to the cell, is not interfered by false positive, makes vector construction convenient and is expressed without specificities of species, tissues and positions.