192 results about "Fluorescence ratio" patented technology

The invention relates to a preparation method of a fluorescent molecular probe for detecting sulfite ions through naked eyes and fluorescence ratio as well as the application of the fluorescent molecular probe in detecting sulfite ions. The fluorescent molecular probe is prepared by condensing 4-hydroxy naphthalimide serving as raw material and acetylpropionic acid in refluent methylene dichloride. The synthesis is simple and convenient, and the reaction conditions are mild. The probe molecule provided by the invention has higher sensitivity, stable fluorescence performance, higher synthesis yield and good selectivity, and furthermore, the response range of the probe is 0-1500 mu m, the detection limit is 6 mu m; the detection range is wide, the lower detection limit is low, and the probe is suitable for naked eye detection. Meanwhile, the florescence-ratio detection is adopted to avoid errors caused by exciting light intensity, probe concentration and environment factors of an off-on type probe which detects ions only depending on the change of fluorescence intensity and the probe disclosed by the invention is not influenced by anions such as F<->, Cl<->, Br<->, I<->, HPO4<2->, SO4<2->, NO<3->, AcO<->, ClO<4->, N<3-> and HCO<3->. Even interfering ions exist, the probe has very good response to sulfite ions. Therefore, the fluorescent molecular probe has practical application value in the fields of biochemistry, environmental science and the like.

The invention relates to preparation and application methods of ratio-dependent bisulfite ion fluorescent probes, belonging to the technical field of anion detection. The probe molecules have recognition specificity for bisulfite ions in a neutral aquatic environment, generate fluorescence ratio variations, have very high sensitivity, and meanwhile, cause obvious color and fluorescent color variations. The fluorescent probes do not generate obvious variations for other ions, free radicals or molecules. The invention implements recognition specificity of the probe molecules for the bisulfite ions, provides the fluorescent probes with color comparison sensing function, and thus, has wide application prospects in the fields of biology and ion detection.

The invention provides a ratio type fluorescent probe, namely TPENS-O, for identifying hydrogen peroxide. The chemical structure formula of the ratio type fluorescent probe is shown in formula (I). The fluorescent probe is used for identifying hydrogen peroxide through fluorescence ratio change. The formula is defined in the description.

Systems and methods for imaging are presented. The method includes producing excitation light configured to induce fluorescence in an imaging agent that selectively binds to a target species in a region of interest (ROI) of a subject that also includes a background species. A first and a second spectral region are selected such that a determined difference between fluorescence corresponding to the target and the background species in the first spectral region differs from a corresponding difference in the second spectral region. First and second fluorescence images are generated from the fluorescence corresponding to the first and second spectral regions. Additionally, a fluorescence ratio for the background species in the first and second fluorescence image is determined. The first fluorescence image is then multiplied or divided with the determined ratio to generate an intermediate image that is subtracted from the second fluorescent image to reconstruct a background-subtracted image.

A method for high throughput discovery of proteins fluorescently labeled at a cysteine residue and that undergo a change in fluorescence ratio at 2 wavelengths upon binding an unbound analyte is described. Probes are disclosed which are labeled at a cysteine residue and also probes labeled at both cysteine and lysine with two different fluorophores. These probes are useful for characterization and measurement of hydrophobic species in a fluid sample, particularly characterization and measurement of levels of unbound free fatty acids. A profile of unbound free fatty acids can be determined for an individual which can be used to determine the individual's relative risk for disease.

The present invention discloses a TBET mechanism based hypochlorous acid fluorescence ratio probe, and the hypochlorous acid fluorescence ratio probe is a mono-thio bi-hydrazide core structure organic small molecule compound which is formed by connection of Rhodamine B thio-hydrazide and 6-dimethylamino-2-naphthoyl, and has the chemical structural formula of formula (I). The TBET mechanism based hypochlorous acid fluorescence ratio probe can selectively effect with hypochlorous acid, with increasing of concentration of the hypochlorous acid, the fluorescence emission intensity at 585nm gradually increases, and gradually weakens at 440nm; and the relation of the ratio (I585 / I440) and hypochlorous acid concentration in a certain range is linear. Intracellular ratio imaging can be achieved, and the TBET mechanism based hypochlorous acid fluorescence ratio probe is expected to play a role in industrial production and clinical medicine, and has broad application prospects.

The invention discloses a fluorescent probe for detecting hypochlorous acid by a fluorescence ratio method and a preparation method for the fluorescent probe, and relates to a fluorescence detection method. The preparation method comprises the steps of adding 1 part of 7-diethylin-4-methylcoumarin into a container by mass, and dissolving the 7-diethylin-4-methylcoumarin by 20-60 parts of redistilled benzene; then adding 1-3 parts of a Lawesson's reagent, performing stirring, heating and backflow reaction on reactants under the nitrogen atmosphere for 4-6 hours; cooling to room temperature, and performing rotary evaporation to exhaust an organic solvent; adding 10-20 parts of ethyl acetate, stirring for 5-10 minutes to separate out the excessive Lawesson's reagent (white solid), pouring out a solution, and performing decompression to remove the solvent; repeatedly operating for 3 times; stewing a product in a vacuum dryer for more than 48 hours to obtain a yellow pure solid product which is the fluorescent probe for detecting the hypochlorous acid by the fluorescence ratio method.

The invention relates to a synthesis method of a Schiff base sensor molecule, and belongs to the technical field of anion detection. The sensor molecule has the advantages of highly selective colorimetric fluorescent binary channel identification of CN<-> in water, short response time, and no influences of anions on the detection process. Determination results show that the naked eye detection limit and the fluorescent spectrum detection limit of the sensor molecule to CN<-> in water are 2.0*10<-6>mol/L and 3.42*10<-8>mol/L respectively, and are far lower than the content standard (below 1.8muM) of normal drinking water, prescribed by World Health Organization.

The invention relates to a preparation method of a fluorescence molecular probe contanining cyanogens ions and having naked eye identification and fluorescence ratio detection as well as an application of the fluorescence molecular probe in detection of cyanogen ions. The fluorescent molecules provided by the invention are synthesized with benzothiazole-2-acetonitrile under the condition that taking piperidine is taken as an alkali by taking diethylin coumarin as a raw material. The synthesizing method is simple and convenient and mild in reaction condition. The probe provided by the invention is high in molecular sensitivity, stable in fluorescent performance, high in synthesizing yield, good in selectivity, wide in response range, low in limit of detection and suitable for naked eye detection. The fluorescence probe is not affected by anions such as AcO<-1>, H2PO4<2->, NO3<-1>, ClO4<-1>, HSO4<-1>, F<-1>, Cl<-1>, Br<-1> and I<-1>. The ratio type fluorescence probe can overcome external errors caused by strength of exciting light, concentration of probe and environmental factors, so that the fluorescence molecular probe has an actual application value in the fields of biochemistry, environmental sciences and the like.

The invention relates to a fluorescence probe, in particular to a fluorescence probe for detecting human serum albumin and a preparation method therefor. The molecular structural formula of the fluorescence probe is as shown in the specification. Quinoline fluorogen is used as a reporter group, a fluorescence ratio probe combined with diethyl oxalate has better effect in HSA detection; and the preparation method is simple in technology and easy to realize.

The invention discloses a hemicyanine compound for detecting polarity of mitochondria. The hemicyanine compound has a structure as shown in formula I, wherein R1 and R2 are independently selected from H, C1-18 alkyl, SO3R5 and COOR5; R3 and R4 are independently selected from H, C1-18 alkyl, SO3R5 and COOR5; R5 is selected from H and C1-18 alkyl, Y<-> is Cl<->, Br<->, I<->, I<-> or OTs<->. The compound has a structure with a formula I. The probe is very sensitivity to the environmental polarity, and can be used for detecting the polarity of the solution. The probe can be used for positioning mitochondria, and detecting polarity of the mitochondria of cells in different states, normal cells and cancerous cells through fluorescence ratio imaging.

The invention discloses a detection method of heavy metal lead ions. A ratio fluorescent biological probe is finally formed by modifying nanogold on the surface of an aminated magnetic bead to form a fluorescence quenching body, connecting the nanogold to a sulfhydrylated DNA enzyme through an Au-S bond and modifying red quantum dots to form a red fluorescent probe, and combining with a substrate chain modified with green quantum dots at the other end through base complementary pairing. Under the effect of DNA, Pb<2+> can recognize and shear the substrate chain, so that a distance between the green quantum dots and the nanogold is changed, the quenching and recovery of green fluorescence are realized, and finally, the quantitative detection of Pb<2+> is realized through the change of a red-green fluorescence ratio due to the change of the green fluorescence intensity. The method has the characteristics of simplicity and convenience, a double-signal detection mode is adopted, the influence of a background environment on a detection result is effectively reduced, and an experiment error is reduced; the method is simple and feasible to operate, low in detection cost and capable of realizing quantitative detection of a target object through a fluorescence spectrophotometer.

The invention relates to the technical field of nano materials, and in particular to a method for selective sensitive mercury ion detection based on a gold nano-cluster fluorescence ratio detection test strip. The method comprises the following steps: firstly, preparing gold nano clusters with two different fluorescence emissions, that is, a bovine serum albumin coated gold nano-cluster (BSA-Au NCs) and cysteine coated gold nano-cluster (Cys-Au NCs); according to an appropriate proportion, concentration and pH conditions, preparing a fluorescence ratio probe, wherein the detection range is 50 nM-3 [mu]M, the minimum price detection limit is 9 nM, and the fluorescence ratio probe is as shown in figure 1 in the specification; finally preparing the fluorescence ratio detection test strip. By adopting the method, the fluorescence ratio detection test strip is prepared under gentle conditions and is applied to detection on mercury ions in an actual water sample.

The invention discloses a two-sided Schiff base sensor molecule based on dianisidine and 2-hydroxy-1-naphthaldehyde. The two-sided Schiff base sensor molecule has a fluorophore naphthalene ring structure, the naphthalene ring has -OH, the Schiff base has a -C=N- structure, and metal ions Cu<2+> can easily coordinate with N and O atoms to form a complex, so the two-sided Schiff base sensor molecule can identify Cu<2+>. H<2>PO<4><-> is added to a complex formed by the sensor molecule M and Cu<2+> to make Cu<2+> and H<2>PO<4><-> form a more stable complex, so Cu<2+> is substituted in am acceptor, thereby Cu<2+> and H<2>PO<4><-> can be continuously identified. The sensor molecule can conveniently, rapidly and efficiently detect Cu<2+> and H<2>PO<4><-> in an aqueous system, and the sensor molecule can be switched into different fluorescence emission states comprising opening (strong fluorescence emission) or closure (fluorescence quenching), so the sensor molecule can also be applied in the field of molecule switches.

The invention discloses a method for rapidly quantifying exosome by using fluorescence ratio, and belongs to the technical field of fluorescence detection. The method relates to two fluorescent dyes,wherein dye A is a highly water-soluble dye with no affinity to a membrane structure and is used as an internal reference in the experimental process; dye B is a special washing-free membrane dye, andcan show strong luminescence properties after being combined with a lipophilic membrane structure, however, because of the hydrophobicity, the dye B is aggregated without fluorescence in a water environment of not combining with a hydrophilic membrane structure. The invention provides the method for rapidly quantifying the exosome; based on the quantitative ratios of the two fluorescent dyes, thedetermination of the exosomes in a biological sample is successfully realized. The method has the advantages of high efficiency, low cost, convenience in operation, high accuracy of determination results and the like. The method is expected to be widely used in related researches of the exosomes and is applied to cell culture mediums, saliva, serum, urine and emulsion.

The invention discloses an organic bi-metal gel capable of recognizing cyanic group ions through a fluorescent colorimetric method. The gel is prepared by dissolving a gelator, namely 1-naphthyl-3,4,5-tri(hexadecyloxyl) benzoyl hydrazone, Ca<2+>, and Cu<2+> into an organic solvent, and cooling to the room temperature so as to form the organic bi-metal gel. When negative ions are added into the organic bi-metal gel, only CN<-> can convert the color of the organic bi-metal gel from dark green to tawny, and very strong fluorescence is generated at the same time; other negative ion aqueous solution do not change the color of the organic bi-metal gel, and no fluorescence is generated; so the organic bi-metal gel can recognize the CN<-> in water liquid through a fluorescent colorimetric method in a mono-selectivity way, so that a person can quickly and conveniently detect CN<-> in water through his naked eyes.

The invention provides a cadmium-based metal-organic framework material. The chemical general formula of the material is {[Cd2 (etc) (tpt) 4/3] (H2O) 9} n, the material belongs to a trigonal system, the space group is P-3c, and the cell parameters are as follows: a=27.3972(7) angstroms, b=27.3972(7) angstroms, c=37.081 angstroms, and V=24104(2) angstrom<3>. In the chemical general formula, a component etc<4-> is obtained by removing four protons from semi-rigid quaternary organic carboxylic acid H4etc, the structure of the H4etc is shown as a formula I, and the structure of a component tpt isshown as a formula II. The preparation conditions of the cadmium-based metal-organic framework material are mild, and the yield can reach 56%. The framework material has good water stability, has thermal stability close to 400 DEG C, emits blue fluorescence at 473nm at room temperature, has a specific surface area BET value of 624.43m<2>/g and an N2 adsorption value of 165.27cm<3> (STP)/g at 77K temperature, and can be used for storage and preliminary identification of aluminum ions and heavy metal barium ions.

The invention relates to a fluorescence ratio probe as well as a synthesis method thereof and application thereof to detection on intracellular lysosomal formaldehyde, and belongs to the field of analytic chemistry. The structural formula of the fluorescence ratio probe is shown in the description. The preparation method comprises the following steps: preparing methionine carbon dot solid powder;and preparing a fluorescence ratio probe crude product and substituting by using hydrazine hydrate to obtain the fluorescence ratio probe, wherein the fluorescence ratio probe is used for detection formaldehyde and particularly used for detecting formaldehyde in the water environment and formaldehyde in a biological sample. The fluorescence ratio probe successfully realizes detection of intracellular and extracellular formaldehyde, has high selectivity and detection sensitivity and provides important theoretical significance in that the double-emission fluorescence ratio probe is further applied to the fields of biomarkers and the like in the future.

The invention relates to a fluorescent ratio probebased on the aggregation induced luminescence property and detection application to hydrogen peroxide and glucose of thefluorescent ratio probe and belongs to the intersection field of chemistry and materials science. The fluorescent ratio probe comprises tetraphenylethylenesulfonate and gold nanoclusters coated with bovine serum albumin. The aggregation induced luminescence phenomenon is generated by the tetraphenylethylenesulfonatedue to the effect of electrostatic adsorption of the tetraphenylethylenesulfonate and the gold nanoclusters, a mixed solution presents dual emission wavelengths in410-550nm and in 500-850 nm correspondingly, and when the ratios of the tetraphenylethylenesulfonateto the gold nanoclustersare different, presented colors of a mixed fluorescent probe are different. Aggregation induced luminescence of the tetraphenylethylenesulfonate can be used as a reference fluorescence color, detection of the hydrogen peroxideand the glucose can be achieved according tothe linear change relationship betweenthe change value of the double emission peak fluorescence ratios (I<0>-I)/ I<0> and analyte concentration C, and thefluorescent ratio probe has the advantages of being simple, fast and visual in the detection of the hydrogen peroxide and glucose.

The invention provides a fluorescent probe for detecting mercury ions and a preparation method and application of the fluorescent probe. The chemical name of the fluorescent probe is 3-(4-(1,3,5,7-tetramethyl-8 propyl)boron fluoride dipyrrol-4-carbonyl)piperazine)-rhodamine B hydrazide. The fluorescent probe takes a boron fluoride dipyrrol fluorescent dye BODIPY unit as an energy donor, a rhodamine unit serves as an energy receptor, by means of bivalent mercury ions, 'on-off' of a spiramide ring is promoted, the purpose that the BODIPY unit and the rhodamine unit are subjected to fluorescenceresonance energy transfer to cause fluorescent red shift is achieved, and then a fluorescence ratio type probe can be used for detecting Hg<2+>; the fluorescent probe takes n-(3-hydroxyphenyl)piperazine and 2-(4-diethylamino)-2-hydroxyl)-benzoic acid as the raw materials, after a reaction is conducted, the raw materials and (1,3,5,7-tetramethyl-8-propoxycarbonyl succinimide)boron fluoride dipyrrolare subjected to a condensation reaction, and the fluorescent probe is obtained. The probe is an FRET-based ratio type fluorescent probe which is high in sensitivity, good in selectivity and capableof detecting the mercury ions in an aqueous phase.

The invention discloses a CN<-> sensor molecule. Identification of CN<-> by the sensor molecule is realized through CN<-> addition, deprotonation, and hydrolysis under the action water to form a ketone structure, and the above reaction has the advantages of good selectivity on CN<->, high identification sensitivity, short reaction time, and no interference of other anions to the detection process. Titration experiments show that the naked eye detection limit of the above sensor to CN<-> in water is 2.4*<-6>mol/L, the fluorescent spectrum detection limit is 8.00*10<-7>mol/L, and the detection limits are far lower than the content standard (below 1.9[mu]M) of CN<-> in normal drinking water, prescribed by World Health Organization. Compared with traditional CN<-> sensor molecules, the CN<-> sensor molecule disclosed in the invention has the characteristics of cheap and easily available raw material, simple and easy synthesis process, and low synthesis cost, so the sensor molecule in the invention has potential application values.

The invention designs and synthesizes a sensor molecule for recognizing iron ions and fluorine ions through fluorescence-colorimetric relay. A rigid structural group benzimidazole is introduced into the sensor molecule, so that the sensor molecule has an excellent aggregation fluorescence property. The sensor molecule can be self-assembled into a supermolecule organogel in various mixed aqueous solutions; after the organogel is combined with the iron ions, a metal organogel is formed, the gel color is changed from white to blue and the aggregation fluorescence quenching phenomenon happens, so that the colorimetric-fluorescence recognition for the iron ions is realized; the metal organogel can be used for further recognizing the fluorine ions, the color of the metal organogel is recovered from blue to white, and meanwhile, the fluorescence radiation property is recovered, so that the 'OFF-ON' signal reflection of the sensor molecule is realized. The synthesis of the 'ON-OFF-ON' type sensor molecule can realize the multifunctional application of the sensor.