900 results about "Quenching (fluorescence)" patented technology

The invention discloses an in-situ composite system based on a carbon quantum dot / manganese dioxide nanometer sheet layer and a using method of the in-situ composite system. The using method comprises the following steps: firstly, completely quenching fluorescence by using a manner that carbon quantum dots are adsorbed on a manganese dioxide nanometer sheet layer prepared by reducing potassium permanganate in situ, and then quantitatively analyzing and determining the content of the GSH in a GSH to-be-tested sample based on a principle of causing digestion of the manganese dioxide nanometer sheet layer, releasing the carbon quantum dots and recovering the fluorescence thereof by virtue of a redox reaction between glutathione (GSH) and manganese dioxide. According to the in-situ composite system, the detection method is high in precision, the repeatability is good, a used carbon material is low in price, easily available, and free from polluting the environment, and has relatively good biological safety; meanwhile, the in-situ composite system is simple and convenient to operate, relatively strong in practicability, high in sensitivity, and excellent in selectivity of the GSH.

The invention discloses a nitrogen-doped carbon nanometer particle as well as a preparation method and application thereof, belongs to the field of nanometer material science and is used for solving the technical problems that fluorescence quenching is easily caused to the aggregative state of the carbon nanometer particle due to surface passivation modifier which is added for the preparation of existing carbon nanometer particles. The nitrogen-doped carbon nanometer particle is prepared through a microwave method by using organic compounds containing polycarboxyl or polyhydroxy as materials and using ammonia water as a solvent and a nitrogen doping source. The invention further provides the application of the nitrogen-doped carbon nanometer particle as fluorescent ink and fluorescent glue. The preparation method disclosed by the invention is simple, low in cost, and convenient to realize large-scale production; the maximal fluorescent quantum efficiency of the solid film formed by the prepared fluorescent glue is as high as 84%; the prepared fluorescent ink is non-toxic, generates no precipitates after being placed for a long time, is strong in fluorescence characteristic and can be applied to various fields such as bio-imaging, biological product identification, information storage, information encryption, counterfeiting prevention, illumination and display, sensing and photovoltaic devices.

In scanned optical systems such as confocal laser microscopes wherein a beam of light is focused to a spot in a specimen to excite a fluorescent species or other excitable species in the spot, the effective size of the excitation is made smaller than the size of the spot by providing a beam of light of wavelength adapted to quench the excitation of the excitable species, shaping this second beam into a pattern with a central intensity minimum, and overlapping this central minimum with the central intensity maximum of the focused spot, so that within the spot the intensity of quenching light increases with distance from the center of the spot, thereby preferentially quenching excitation in the peripheral parts of the spot, and thereby reducing the effective size of the excitation and thus improving the resolution of the system. In the preferred embodiment of the present invention, the central minimum of quenching light is narrowed further by creating the pattern of quenching radiation in the specimen by imaging onto the focal plane a plurality of pairs of sources of quenching light, arrayed at the vertices of a regular, even-sided polygon, the center of which is imaged in the specimen on the central maximum of exciting radiation, and such that the two members of each pair are on opposite vertices of the polygon and emit light mutually coherent and out-of-phase, and the light emitted by different pairs is incoherent with respect to each other.

The invention discloses a multi-target quantum-dot mark nucleic acid chip and a preparation method and a detection method thereof, wherein the nucleic acid chip comprises a solid phase holder and an oligonucleotide probe array fixed on the surface of the solid phase holder, wherein the oligonucleotide probe array comprises at least two oligonucleotide probes which do not contain self-complementary sequences; one end of the oligonucleotide probe marks quantum dots and is fixed by the quantum dots, and the oligonucleotide probes with different sequences are marked by the quantum dots which emit fluorescence with different wavelengths; or the oligonucleotide probe array comprises at least two molecular beacons, wherein one end of the molecular beacon marks quantum dots and is fixed by the quantum dots, the molecular beacons with different sequences are marked by the quantum dots which emit fluorescent with different wavelengths, and the other end of the molecular beacon is marked by a fluorescence quenching group. By utilizing the basic-group complementation pairing principle and the FRET phenomenon, the detection of a plurality of special nucleic acid sequences in a nucleic acid sample to be detected can be simultaneously achieved; in addition, the invention has simple preparation and accurate, sensitive, simple, convenient and rapid detection and can detect a plurality of samples simultaneously.

The invention provides a pillar[5]arene and 2-hydroxy-3-naphthoic acid complex.Copolymerized pillar[5]arene serves as a subject, 2-hydroxy-3-naphthoic acid serves as an object, C-H......pi and electrostatic attraction serve as driving force, partial 2-hydroxy-3-naphthoic acid provided with negative charges is included into a cavity of pillararene in an alkaline environment, the assembling process of the subject and the object is completed, and the stable pillar[5]arene and 2-hydroxy-3-naphthoic acid complex is formed.Iron ions are added to an alkaline aqueous solution of the complex, and the subject and the object are subjected to fluorescence quenching; fluorine ions are added, a complex is formed by the fluorine ions and the iron ions, so that the iron ions are separated from the cavity of copolymerized pillar[5]arene, and molecular fluorescence of the complex is reopened.Therefore, Fe<3+> can be determined through the pillar[5]arene and 2-hydroxy-3-naphthoic acid complex, and F<-> can be continuously identified through fluorescence quenching of the solution.

The invention discloses a mercury ion detection method which is characterized by comprising the following steps: (1) mixing a standard mercury ion solution and a gold nanocluster solution, and establishing a standard curve for detecting the fluorescence signal quenching of nanocluster and the mercury ion quantity; and (2) mixing a sample solution with the gold nanocluster solution, substituting the quenching intensity of the fluorescence signal of the nanocluster into the standard curve, thereby obtaining the content of the mercury ion in the sample. The method has the advantages that the sensitivity is high, the interference of other ions on detection of the mercury ion is slight, and selective detection of the mercury ion can be realized, so that the aim of rapidly detecting the mercury ion concentration is achieved. The method has wide application prospects in mercury ion detection.

A hydrotalcite composite luminescent material with rhodamine intercalation, which pertains to abio-organic composite luminescent material. The process is preparing solution A with mole ratio of bivalence and tervalence cation M2+ / M3+=2.0-4.0; adding laser dye sulphonated rhodamine and sodium salt of dodecylbenzene sulfonic acid into mixed solution of ethanol and water and fully dissolving to obtain solution of sulphonated rhodamine and dodecyl benzene sulfone acid group containing anion with negative charge B; mixing solution A, B into solution C, preparing NaOH solution; communicating solution C and NaOH solution into full-back-liquid mixing membrane reactor to react, mixing to obtain red slurry, introducing the red slurry into hydrothermal kettle, reacting, absterging by CO2, de-ionized water and absolute ethyl alcohol and centrifugally separating, vacuum drying. Then hydrotalcite system with co-intercalation of suphonated rhodamine and dodecyl sulfone acid group is obtained. Advantages of the invention are that dye molecular is immobilized, and fluorescence quenching caused by dye aggregation is reduced.

The invention belongs to the field of medical materials, and discloses a benzylidene indandione compound and a preparation thereof and an application in specific imaging of a lipid droplet. The structure of the benzylidene indandione compound is as shown in a formula I. The benzylidene indandione compound has the advantage of aggregation-induced emission, and the defects of aggregation-induced quenching of a traditional fluorescent dye can be effectively overcome, so that the specific fluorescence imaging of the lipid droplet in a living cell can be achieved; furthermore, the benzylidene indandione compound has a two-photon absorption cross-section which is high in living cell penetration rate, high in signal to noise ratio, small in cytotoxicity, large in stokes shift and large in near infrared region. The formula I is as shown in the specification.

This invention provides an organic electroluminescent device, a method of preparing the same, a display substrate comprising the same, and a display apparatus. According to the invention, the agglomeration and self quenching of quantum dots can be effectively prevented as the quantum dots are uniformly dispersed in electroluminescent polymer fibers. Due to the fluorescence resonance energy transfer effect between the electroluminescent polymer and the quantum dots, a higher quantum yield is achieved, and the luminescence efficiency of the quantum dots can be improved accordingly. Furthermore, since the light emission from the quantum dots is achieved by the fluorescence resonance energy transfer effect, which is an energy transfer process without damage to the quantum dots, the damage to quantum dots is less and thus the lifetime thereof can be beneficially increased, as compared to the direct charge injection mode of the prior art.

The invention belongs to the field of iodide ion (I-) sensing technology, and specifically relates to a sensing material with 2,7-position of fluorene as the main chain and flexible alkyl connected carbazole group as the side chain. The sensing material has advantages of inexpensive and easily-obtained raw materials, simple synthesis steps and excellent detection sensitivity and ion selectivity. In common negative ions, the material only has responses to I-. When the concentration of I- in the system is 0.3 mM, the fluorescence quenching of the solution is close to 100%, and there is basically no change with the addition of other negative ions. Apart from good fluorescence detection selectivity and sensitivity, the sensing material is more excellent in chromogenic detection. When the concentration of I- in the solution system reaches 0.1 mM, obvious color change (from colorless transparency to yellow) can be observed by naked eyes. The I- detectable concentration accounts for 1 / 100 ofcurrently reported I- chromogenic sensing material. Therefore, the iodide ion sensing material provided by the invention is a good sensing material and has a wide application prospect.

The invention discloses a method for preparing a bioluminescent nano thermometer. The prepared bioluminescent nano thermometer is characterized in that: on the one hand, the fluorescence intensity is controlled through temperature by using a fluorescence quenching effect; at a low temperature, because the thermo-sensitive polymer is in a stretching state, the distance between fluorescent active molecules and metal silver nano spheres is prolonged, the fluorescence quenching effect is weak, and fluorescent signals are strong; when the temperature is raised, the thermo-sensitive polymer is shrunk, so that the distance between the fluorescent active molecules and the metal silver nano spheres is shortened, the fluorescence quenching effect is enhanced, and the fluorescent signals are weakened; and on the other hand, the maximum fluorescence intensity of the bioluminescent nano thermometer is linearly changed together with the environmental temperature, the fluorescence intensity is sensitive together with temperature change, and the maximum fluorescence intensity and the fluorescence intensity can be quantitatively and correspondingly valued, so that the prepared bioluminescent nano thermometer can be used as a nano thermometer.

The invention discloses application of dual-fluorophore ratio fluorescence molecular probe for non-fluorescence resonance energy transfer, and relates to application of the dual-fluorophore ratio fluorescence molecular probe. The dual-fluorophore ratio fluorescence molecular probe disclosed by the invention is designed for solving the technical problems that due to energy loss caused by energy transfer between double fluorophores when the existing dual-fluorophore ratio fluorescence molecular probes are excited, the probes are poor in fluorescence, and not high in metal ion selectivity and sensitivity. The dual-fluorophore ratio fluorescence molecular probe for non-fluorescence resonance energy transfer is used for identifying fluorescence peak quenching of Cu2+, Cu2+ to the dual-fluorophore ratio fluorescence molecular probe for non-fluorescence resonance energy transfer at the position of 474nm, while the fluorescence peak strength at the wavelength of 351nm basically remains unchanged. The dual-fluorophore ratio fluorescence molecular probe disclosed by the invention can be applied to the fluorescence imaging detection of metal ions in biological tissue and cell microenvironments.