903 results about "Fluorescence sensor" patented technology

A microresonator sensor apparatus has a microcavity resonator that defines equatorial whispering gallery modes (EWGMs), whose frequencies are separated by the free spectral range (FSR). The EWGMs lie in a plane perpendicular to a microcavity resonator axis. A light source is optically coupled to inject light into the microcavity resonator. The light source produces output light having an output spectrum whose bandwidth is approximately equal to or broader than the FSR of the EGWMs. One or more fluorescent materials are excited using the excitation light coupled into the microcavity resonator. A fluorescent signal arising from fluorescence of the one or more fluorescent materials is then detected.

A probe comprises: (1) a target binding site moiety which is attached to a first fluorescent polypeptide; (ii) a mimic moiety which is capable of binding to the target binding site moiety and is attached to a second fluorescent polypeptide; and (iii) a linker which connects the two fluorescent polypeptides and which allows the distance between said fluorescent polypeptides to vary, said fluorescent polypeptides being so as to display fluorescence resonance energy transfer (FRET) between them, wherein the linker comprises one or more of: (1) a sequence capable of being recognised and bound by an immobilized component; (2) a protease cleavage site; (3) a non-analyte binding site; (4) two or more copies of the sequence (SerGly3); or (5) one or more copies of a rod domain from a structural protein. Probes of the invention are used, for example, in the detection of a wide range of substances or in the identification of inhibitors of the interaction between two substances which, in the absence of an inhibitor, interact with each other.

The present invention relates to novel fluorophores and their use in combination with novel nucleic acid molecules, called aptamers, that bind specifically to the fluorophore and thereby enhance the fluorescence signal of the fluorophore upon exposure to radiation of suitable wavelength. Molecular complexes formed between the novel fluorophores, novel nucleic acid molecules, and their target molecules are described, and the use of multivalent aptamer constructs as fluorescent sensors for target molecules of interest are also described.

The invention discloses a quantum dot molecular imprinting microsphere quartz fluorescent sensor for detecting multicomponent food additives simultaneously and a method for detecting the food additives by the quantum dot molecular imprinting microsphere quartz fluorescent sensor. A method for preparing a quantum dot molecular imprinting microsphere comb quartz plate comprises the following steps of: selecting functional monomers corresponding to the food additives; preparing quantum dots and preparing quantum dot molecular imprinting microspheres according to the literature; and modifying thesurfaces of different probes of the comb quartz plate with the imprinting microspheres of different food additives by utilizing layer-upon-layer accumulated surface modification technology. The method for detecting the trace multicomponent food additives simultaneously (which is shown as the figure) comprises the following steps of: immersing the modified quartz plate into simply-pulpified food solution, arranging the quartz plate on a sealing quartz vessel, and detecting the food additives in a sample. The quantum dot molecular imprinting microsphere quartz fluorescent sensor has high specificity and sensitivity, short detection time and low cost; and in a method for detecting pesticide residues by fluorescent light, the operation is simple and quick, and reactions and results are completed and recorded automatically by instruments.

An integrated particle detection apparatus for optical detection of particles in an air stream. The particle detection apparatus includes a scalper for removing large panicles from the air stream, a concentrator for separating out small particles and increasing the concentration of particles of interest, and a fluorescence sensor system for detecting the particles present in the air stream. The scalper, concentrator and sensor comprise a single integrated unit, such that the scalper is fluidly contiguous with the concentrator and the concentrator is fluidly contiguous with the sensor.

A light waveguide includes: a light introducing portion for introducing light coming from a light source into a waveguide main body; a light radiating surface for radiating the light introduced through the light introducing portion to the hydrogel side; a light transmitting surface which is disposed opposite to and in parallel to the light radiating surface and through which external light incident from the light radiating surface is transmitted to the exterior; a light separation portion, which provided on a surface in a region ranging from the light introducing portion to the light radiating surface and the light transmitting surface, reflecting only totally reflected components of the light introduced through the light introducing portion; an irregular reflection portion provided on the light transmitting surface to change the reflection angle on the light transmitting surface of the light reflected by the light separation portion; and a mirror portion provided at a position opposite to the light introducing portion.

A biological sterilization indicator device is provided. The device comprises a body, a plurality of test microorganisms, and an oxygen-modulated first fluorescent sensor. The body comprises a first layer attached to a second layer, forming at least one isolatable microchamber and at least one primary passageway that provides fluidic communication between ambience and the at least one microchamber. The microchamber has an isolated volume of about 0.5 microliters to about 9.5 microliters. The plurality of test microorganisms and the oxygen-modulated first fluorescent sensor are disposed in the microchamber. A method of using the device to determine the effectiveness of a sterilization process is also provided.

The invention discloses a field effect transistor chiral sensor and a manufacture method thereof. By utilizing the structure of a field effect transistor, the chiral sensor comprises a substrate, a gate electrode, a gate insulating layer, an active layer, a source electrode and a drain electrode. The chiral sensor is characterized in that the active layer is made of a quantum dot material with chiral recognizing and detecting function. The quantum dot material of the active layer is a semiconductor nano microcrystal which is modified by chiral molecules and has the size of smaller than 100nm.The invention sensor capable of detecting a chiral substance by using a quantum dot film with the chiral recognizing and detecting function as the active layer of the field effect transistor on the basis of the quantum dot field effect transistor and the manufacture method thereof. The fluorescent chiral molecule modified quantum dot can be also made into a film by the chiral sensor for being used as the field effect transistor active layer, thereby overcoming the defect of chiral molecule detection by the traditional homogeneous phase fluorescent sensor and realizing a more stable detecting signal.

The invention relates to a fluorescence biosensor, and a preparation method and a purpose thereof. On the basis of a two-dimensional manganese dioxide nanometer sheet as a fluorescence sensing platform, morpholineethanesulfonic acid is used for reducing potassium permanganate for synthesizing the manganese dioxide nanometer sheets; the manganese dioxide nanometer sheets adsorb FAM-ssDNA and quench FAM fluorescence; under the effect of alkaline phosphatase, vitamin C magnesium L-ascorbate-2-phosphate is hydrolyzed to generate ascorbic acid; the two-dimensional manganese dioxide nanometer sheets are reduced into manganese ions by the ascorbic acid; FAM-ssDNA is released; the fluorescence is recovered; the fluorescence sensor using the manganese dioxide nanometer sheets and the alkaline phosphatase to regulate the fluorescence intensity is built and is used for detecting the activity of the alkaline phosphatase. Compared with the prior art, the fluorescence biosensor has the characteristics of simplicity, high speed, low background signal, high sensitivity, low detection limit and good selectivity by using the change of the two-dimensional manganese dioxide nanometer sheets on the fluorescence signal, i.e., the off-on mode for detecting the alkaline phosphatase.

The invention discloses a method for recognizing quantitative chiral amino acid by using a reversible nano porphyrin fluorescence sensor, and belongs to the technical field of nano material preparation and chemical analysis detection. The reversible nano porphyrin fluorescence sensor for specifically recognizing quantitative proline, lysine and serine chirality adopts a CdTe quantum dot as a fluorescence probe, and self-assembled porphyrin prepared from a tetra-(4-pyridyl) zinc porphyrin tetrahydrofuran solution and cetyl trimethyl ammonium bromide (CTAB) as a fluorescence quencher, and with the specific combination of the florescence probe and the fluorescence quencher, an openable/closeable nano porphyrin fluorescence sensor can be prepared. The reversible (opening-closing-opening) nano porphyrin fluorescence sensor can be prepared under the action of the openable/closeable nano porphyrin fluorescence sensor with the chiral proline, lysine and serine. Compared with a conventional chromatographic method for recognizing amino acid chirality by separating, the method disclosed by the invention has multiple advantages.

A fluorescent sensor for detecting mycotoxins and an application method thereof belong to the field of analytical chemistry. The surfaces of two groups of graphene quantum dots are modified respectively with aptamer DNA corresponding to mycotoxins or probe DNA complementary to the aptamer DNA, the graphene quantum dots are aggregated by DNA hybridization, exciton energy is transferred, and graphene quantum dot fluorescent signals are cancelled at last; mycotoxins are added then and engage in specific binding with the aptamer DNA, structural changes occur, the graphene quantum dot aggregation is disassembled and re-dispersed, and the system fluorescent strength is restored. The preparation method of the fluorescent sensor for detecting mycotoxins has a simple and feasible process, and the fluorescent sensor is green, low in cost, high in sensitivity and good in specificity and is successfully applied to standard added recovery of mycotoxins in actual wine samples.

The invention discloses a Fe<3+> molecular fluorescence sensor based on Rhodamine B and a preparation method and application of the Fe<3+> molecular fluorescence sensor. Rhodamine B is taken as a precursor, and a target product N1-(benzene[d] thiazole-2-yl)-N4-(2-(3',6'-bi(diethylin)-3-carbonyl screw[iso-indoline-1,9'-xanthene]-2-yl)ethyl) maleimide is synthesized at two steps. Detection on Fe<3+> by using the target product shows that the target product has a very good detection effect on Fe<3+>; and meanwhile the raw materials of the Fe<3+> molecular fluorescence sensor are easy to obtain, synthesis steps are simple, after-treatment is convenient to implement, and large-scale production can be relatively easily achieved.

The invention discloses an application of a rhodamine B based fluorescence sensor which can specifically detect tin ions. According to the application, benzyl 3-(3', 6'-bis(diethyl amino)-3-oxo-spiro [isoindoline-1, 9'-xanthene]-2-yl) ethyl propionate is taken as a substrate, different heavy metal ions such as MgCl2*6H2O, SnCl2*H2O, CrCl3*6H2O, AgNO3, CaCl2, NaCl, PbCl2, KCl, MnCl2*4H2O, ZnCl2, CuCl2*2H2O, LiCl*H2O, Ba(NO3)2, HgCl2, CoCl2, FeCl2*4H2O, FeCl3*6H2O, CdCl2*2.5H2O, AlCl3 and the like are added, and fluorescent response is found only when SnCl2*H2O is added, so that the fluorescence sensor which can specifically detect tin ions is developed. The sensor has the advantages of high specificity and sensitivity and the like and has important application potentials in the aspects of disease diagnosis and health evaluation.