87results about How to "Stable fluorescence" patented technology

There is a kind of nano particle and micro-sphere biological fluorescence probem and the manufacturing method. The method mainly includes: 1) hydrosulphenyl compound with amidocyanogen is used as stabilizing agent in particle synthesis, water-soluble fluorescence nano particle whose surface is bedecked with amidocyanogen is directly prepared under mild condition, then it takes advantages of the amidocyanogen on the surface of particle to couple with biological system directly, further nano-particle biological fluorescence probe is acquired; 2) said fluorescence nano particle whose surface is bedecked with radical dumpling with different functions is compounded into micro-sphere is inorganic silicon dioxide or organic polymer by various means, fluorescence micro-sphere which can be dispersed equably in aqueous solution is acquired.

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 discloses synthesis and application of a fluorescence-enhanced fluorescent molecular probe for rapidly detecting hydrogen sulfite ions or sulfite ions. The structural formula of the fluorescent molecular probe is shown as FORMULA (1). The fluorescent molecular probe for rapidly detecting the hydrogen sulfite ions or the sulfite ions, provided by the invention, has the advantages of high response (15 s), low detection limit (48 nM), high selectivity, high sensitivity, suitability for naked eye detection, wide pH application range and the like, and can be applied to detection of the hydrogen sulfite ions or the sulfite ions in living cells; the fluorescent molecular probe is not interfered by negative ions such as AcO-, CO32-, F-, Cl-, Br-, HCO3-, NO3-, S2O32-, HS-, SO42-, HPO42-, H2PO4-, PO43-, SCN- and the like; even in the presence of interfering ions, the fluorescent molecular probe also has good response to the hydrogen sulfite ions or the sulfite ions and has the detection limit as low as 48 nM, so that the fluorescent molecular probe is a very sensitive detection system; the fluorescent molecular probe can be applied to analysis and imaging of the living cells, so that the fluorescent molecular probe has a potential practical application value in the fields of biochemistry, environmental science and the like.

The invention relates to amphiphilic macromolecular modified oil-soluble nuclear / shell quantum dots and a preparation method. A nuclear layer is of CdSe quantum dots; and a shell layer comprises CdS, an alloy layer, ZnS, an amphiphilic polymer layer from the inside to the outside in turn. The structure of the alloy layer is: Cd0.4Zn0.6S, Cd0.45Zn0.55S or Cd0.6Zn0.4S; the structure of the amphiphilic polymer layer is that: an inner layer is an alkyl chain hydrophobic layer; a connecting layer is aliphatic long carbon chains; and an outer layer is a carboxyl hydrophilic layer; and the particle size range of the quantum dots is between 200 and 1,000 nm. By covering different shell layers with appropriate thickness on the surface of the CdSe nuclear quantum dots, the nuclear / shell quantum dots with high fluorescence efficiency and stable fluorescent properties are synthesized; by performing self-assembly water-solubility modification on self-made amphiphilic polymer and amphiphilic polymer, a formed amphiphilic polymer layer protects the surface structure and fluorescence properties of the nuclear quantum dots, can restrain cadmium ions and selenium ions from diffusing outwards and reduces the toxicity of the quantum dots to organisms; and the modified quantum dots cannot generate fluorescence resonance energy transfer in multi-flux detection.

The invention provides a polythymine template, a fluorescent copper nano-cluster based on the same, a preparation method of the fluorescent copper nano-cluster and an ATP detection method. The polythymine template has a single-chain DNA sequence and comprises at least one polythymine sequence which is (T)n, wherein n refers to natural number ranging from 15 to 40. The polythymine template can be used for preparing the fluorescent copper nano-cluster, preparation cost is low, and operation is simple and convenient. The ATP detection method is low in cost, simple and easy-to-implement in detection step, obvious in phenomenon, easy for observation and capable of quickly detection concentration of ATP in a sample in a high-sensitivity manner.

The invention belongs to the technical field of organic photo-functional materials. A photonic crystal assembled by fluorescent microspheres obtained after three-primary-color quantum dots are embedded into particles is characterized by being assembled by the mono-dispersed fluorescent microspheres through a self-assembly method, wherein the fluorescent microspheres comprise mono-dispersed particle kernels and shells which are made of silicon dioxide materials and have uniform thickness, a layer of quantum dots are evenly dispersed on the outer surfaces of the particles through the static effect, the layer of quantum dots are formed by mixing red quantum dots, green quantum dots and blue quantum dots in proportion, and the photonic crystal can be applied to white light emitting diodes.

The invention relates to a preparation method of a fluorescent molecular probe for detecting fluoride ions through colorimetric detection and fluorescence enhancement and an application of the fluorescent molecular probe to detecting fluoride ions. The fluorescent molecular probe is prepared by protecting 2-hydroxyl-1-naphthaldehyde taken as a raw material with silane and then condensing the raw material and malononitrile. The fluorescent molecular probe is simple and convenient to synthesize, and reaction conditions are mild. The fluorescent molecular probe has the specific characteristics that the probe molecule has stable optical properties and higher synthetic yield; the probe molecule has high fluoride ion detection sensitivity and low lower limit of detection, and the limit of detection is 0.52mu M; the response range is 0-100mu M and the detection range is wide; the probe molecule has good selectivity and has no responses to anions, such as dihydrogen phosphate radicals, acetate radicals, bromide ions, hydrosulfate radicals, chlorate radicals, iodide ions, chloride ions and nitrate radicals; the probe molecule is suitable for colorimetric detection; the fluorescent molecular probe has practical application values in the fields of biochemistry, environmental sciences and the like.

The invention discloses a magnetic fluorescent multimodal nano biological probe as well as a preparation method and application thereof. The magnetic fluorescent multimodal nano biological probe specifically targets a liver-cancer cell. According to the preparation method, magnetic nano particles and fluorescent dye are co-embedded in silicon dioxide; an amino group is functionally modified by the silicon dioxide; nucleic acid aptamer and a magnetic fluorescent probe are covalently coupled and synchronously specifically target the liver-cancer cell. The magnetic nano particles are paramagnetic iron oxides of which the sizes are ten nanometers; the fluorescent dye is fluorescein isothiocyanate; the embedding medium silicon dioxide is obtained through the hydrolysis of tetraethyl orthosilicate and 3-aminopropyltriethoxysilane; the nucleic acid aptamer is TLS11a. A synthetic method of the probe is simple and convenient; materials are easily obtained; fluorescence properties are stable; a foundation is laid for the early diagnosis of a liver cancer.

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 discloses a white light source containing three-band-gap photonic crystals and a preparation method for the white light source, belongs to the technical fields of light emission and illumination, relates to the application technology of photonic crystals, and particularly relates to a preparation method for improving the luminous intensity and stability of the white light source based on the three-photonic-band-gap characteristics of the three-band-gap photonic crystals and a coating technology. According to the preparation method, mono-dispersion red, green and blue three-fundamental-color fluorescent granules are prepared separately through the coating technology; then the solid-state luminous thin films of the three-band-gap photonic crystals are established by an automatic-assembling method in a layer-by-layer assembling manner; and next, the thin films are combined with an ultraviolet LED to prepare the white light source with the excellent luminescence property.

The invention belongs to the field of material science and engineering and bioseparation engineering, and concretely relates to a preparation method for a fluorescent western-blotting magnetic composite microballoon. A miniemulsion polymerization method is employed to take phycocyanin as a molecular imprinting template and combine with a magnetically-sensitive fluorescent material, so that the phycocyanin molecular-imprinted-polymer magnetic fluorescent composite microballoon is obtained. By using the miniemulsion polymerization method, the molecular-imprinted-polymer microballoon integrates the magnetic and fluorescence double-responsive material, has specific recognition and autonomous adsorption on phycocyanin, is good in selectivity, high in adsorption efficiency, fast in speed, convenient and rapid for separation under the effect of an external magnetic field, and good in repeated usage performance, and is capable of realizing fluorescence real-time detection and fluorescence imaging at a relatively wide pH scope. Also the obtained magnetic core-shell blotting microballoon is regular in morphology and uniform in particle size. The preparation method has the advantages of low cost, simple and convenient operation, good reappearance and the like, and has wide application prospect.

The invention discloses a preparation method and application of a monodisperse polymer fluorescent microsphere. The invention provides a method for obtaining a functionalized fluorescent microsphere with a surface containing a carboxyl group or an amino group through a one-step method. The method comprises the steps of (1) providing an oil phase mixture, a water phase mixture and an initiator water solution; (2) fully mixing the water phase mixture and the oil phase mixture, pre-emulsifying and completely emulsifying to obtain an emulsion for standby use; (3) uniformly mixing the emulsion forstandby use and the initiator water solution; carrying out polymerization reaction under nitrogen protection and dark conditions, and purifying after finishing reaction, thus obtaining the polymer fluorescent microsphere. The preparation method provided by the invention is simple, the process is environmentally-friendly, and the cost is low; the obtained fluorescent microsphere is controllable inparticle size, uniform in size, high in fluorescent brightness, high in functional group content, and stable in performance, and has a better application prospect in immune side chromatography.

The present invention relates to a method for preparingg carbon nanodots based on chemical cutting, comprising dispersing waste carbon source materials in a mixed concentrated acid which plays a "chemical scissors" role during oxidation and cuts two-dimensional turbostratic structures of fiber materials into fluorescence carbon nanodots with small dimensions. Color of the carbon nanodots is adjusted by changing the reaction time and the temperature, and finally about 8-12nm carbon nanodots can be obtained after dilution, alkali neutralization and dialysis bag interception and separation. Compared with the prior art, the method for preparing carbon nanodots based on chemical cutting is simple in process, can obtain the carbon nanodots with small dimensions by controlling reaction parameters, and does not need special equipment and instruments. The carbon nanodots have stable fluorescence property and good water solubility, and present a multi-colored fluorescent effect.

The invention discloses production of high-quantum-yield sulfur quantum dots and a method for determining an ascorbic acid thereof. The high-quantum-yield sulfur quantum dots disclosed by the invention are produced by taking polyethylene glycol-400 as a cosolvent and a passivating agent and adopting an ultrasonic microwave-assisted method under an alkaline condition. A fluorescence quantum yield of the sulfur quantum dots produced by the method is 58.65%. The high-quantum-yield sulfur quantum dots are used as a fluorescent probe, and based on a quenching effect of Ce (IV) on the fluorescence and redox reaction of Ce (IV) and the ascorbic acid, when the Ce (IV), the ascorbic acid and sulfur quantum dots coexist, fluorescence quenching of the sulfur quantum dots is inhibited so that quantitative detection of the ascorbic acid is realized. The method is low in cost, high in sensitivity, good in linear relation, easy and convenient to operate, good in selectivity and capable of being usedfor measuring the ascorbic acid in an actual sample, and therefore the method has good clinical application prospects.

The invention discloses a preparation method of monodisperse polymer fluorescent microspheres. The preparation method comprises the following steps: (1) synthesizing a europium-containing ternary complex by adopting a coordination reaction; (2) preparing carboxyl polystyrene microspheres by adopting a soap-free emulsion polymerization method; and (3) permeating the europium complex into the functional microspheres by a one-step seed swelling method to obtain the fluorescent carboxyl polystyrene microspheres with fluorescent substances wrapped in the microspheres. Fluorescent functional microspheres are obtained through a one-step swelling method, seed microspheres used for swelling come from carboxyl latex microspheres obtained in a soap-free emulsion polymerization mode, operation is easy, and the obtained microspheres are uniform and controllable in size and regular in surface.

The invention relates to a cell membrane imaging fluorescence probe, in particular to glycosyl-substituted perylene bisimide derivative cell membrane imaging dye. An alkyl chain is introduced into oneend of the derivative, and pyranose is introduced into the other end. The dye can be self-assembled into nano-particles in vitro and enter cells, and then are redistributed in cell membranes, and after the dye is excited, the cell membranes can be specifically imaged. Compared with traditional cell membrane fluorescence dye, the dye is high in biocompatibility and lasting in light and acid stability, and the preparation method is simple, economical and capable of being widely used in cell membrane imaging research, especially, the research on imaging of the cell membranes of tumor cells in aweak acid environment.

The invention discloses a nitrogen-doped carbon quantum dot and a preparation method thereof. The method comprises the following steps: providing an organic phenol, mixing the organic phenol with peroxide in a solvent to carry out a phenolic hydroxyl oxidation reaction to obtain an organic hydrazine; and providing an organic amine to react with the organic hydrazine in a closed environment to obtain the nitrogen-doped carbon quantum dot. By using organic phenol, organic amine, peroxide and deionized water as raw materials, the nitrogen-doped carbon quantum dot which has stable fluorescence performance and stable chemical properties and is dispersible in water and environment-friendly is synthesized. By regulating the ratio of the raw materials and the reaction time, the structure, particlesize and optical performance of the nitrogen-doped carbon quantum dot are regulated. No heat source is needed by the method such that energy consumption is low, cost is low and operation is simple. Meanwhile, the nitrogen-doped carbon quantum dot material prepared by the method does not contain heavy metals such as Cd and Te, and has wider application fields than traditional quantum dot materials.

The invention belongs to the field of application of novel materials to analytical chemistry and discloses a graphene quantum dot and ionic liquid compound and application thereof to Cr(VI) detection. A method for preparing the graphene quantum dot and ionic liquid compound includes: mixing graphene quantum dots with ionic liquid, and purifying after reaction to obtain the graphene quantum dot and ionic liquid compound, wherein the complex is 2.0-4.0nm in size and 0.23nm in lattice spacing, and the ionic liquid refers to 1-butyl-3-methylimidazole bromide. The graphene quantum dot and ionic liquid compound BMIMBr-GQDs has a great fluorescence property and more stable in fluorescence property than graphene quantum dots which are not combined with the ionic liquid. In addition, the BMIMBr-GQDs has an evident Cr(VI) selective recognition capability and is capable of realizing rapid and sensitive detection of Cr(VI) in samples.

The invention relates to establishment of a relay type fluorescence detection of Hg<2+> and S<2-> and aims to solve the problems that very few fluorescence probes are used for relay type fluorescencedetection of Hg<2+> and S<2-> in an aqueous solution in the prior art and recognition of Hg<2+> is easily affected by Au<3+>, Fe<2+> and Fe<3+>. The probe 1,4-o-phenylenediamine-3-(1-amyl benzimidazole)acetanilide chloride [L] can form a stable complex with Hg<2+> in an HEPES aqueous solution, so that fluorescence quenching of L is realized, and the pH value is in the range of 2.0-11.3. The probecan be used for detecting Hg<2+> and has stable fluorescence property; the detection limit of Hg<2+> can reach 4.0*10<-7> mol / L. the compound [L-Hg<2+>] can realize fluorescence detection of S<2->. Therefore, the probe can realize relay type fluorescence detection of Hg<2+> and S<2-> in the aqueous solution and has huge application prospects in the fields of environmental science, analytical chemistry, bioscience and the like.

The present invention discloses a metal complex of a biscalix[4]arene derivative, having a chemical structure represented by formula II. The complex has a small toxicity and a high biocompatibility, is suitable for being covalently combined with nucleic acids, peptides, proteins or other biological molecules to form a fluorescent probe molecule having a high fluorescence quantum ratio, a long fluorescence lifetime and a low detection limit, is suitable for biomolecule detection in cells, tissues or living organisms, and has a broad application prospect in the field of biomedicines. The invention discloses a synthesis method of the complex. The method provides multiple selection routes for the synthesis of the complex, and has the advantages of simplicity and easiness in the synthesis routes, high yield in the obtained complex, and suitableness for large-scale production preparation of the complex.

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 discloses a preparation method and detection method of a fluorescence sensor for an aflatoxin toxin production gene nor-1. The fluorescence sensor is a long-arm hairpin probe based on specific recognition of the aflatoxin toxin production gene nor-1; and the two ends of the long-arm hairpin probe are provided with NH2 and SH correspondingly, a CdTe / CdS quantum dot of an upper core-shell structure is modified by the NH2, and upper gold nanoparticles (AuNPs) are modified by the SH. The preparation method comprises the steps: a CdTe / CdS quantum dot solution is prepared for standby application; the AuNPs are prepared for standby application; and the long-arm hairpin probe is modified. Detection comprises construction of the fluorescence sensor, when the target nor-1 appears, thenor-1 and the hairpin probe are subjected to specific complementary pairing, the hairpin probe is straightened, the distance between the CdTe / CdS quantum dot and the AuNPs is enlarged, transferring offluorescent resonance energy is blocked, thus fluorescence of the CdTe / CdS quantum dot is recovered, the concentration of the nor-1 is tested through the fluorescence recovery intensity, and thus thenor-1 is quickly detected. The prepared fluorescence sensor has the advantages that flexibility, simpleness, quickness and the like are achieved, the toxin production gene is detected from the source, the cost is low, and detection is quick.

The invention relates to a preparation method of rose-bengal B / polystyrene / silicon dioxide fluorescent microspheres. The preparation method comprises the steps that 1, polystyrene / silicon dioxide composite particles are dispersed in a swelling medium, and ultrasound and swelling are performed to obtain polystyrene / silicon dioxide dispersion liquid; 2, rose-bengal B is dissolved in a swelling agentto prepare a rose-bengal B solution; 3, the rose-bengal B solution obtained in the step 2 is mixed with the polystyrene / silicon dioxide dispersion liquid obtained in the step 1, stirring reaction isperformed, and washing, centrifugation and drying are performed to obtain the rose-bengal B / polystyrene / silicon dioxide fluorescent microspheres. The preparation method has the advantages of being simple in preparation process, convenient to operate, low in reaction temperature, capable of saving energy and the like.

The invention provides a carbon nano fluorescent material suitable for a seawater medium. The carbon nano fluorescent material is prepared from the following raw materials: a carbon source A, a nitrogen source B and a passivator, wherein a mass ratio of the carbon source A to the nitrogen source B is 5:1-1:5, the carbon source A is one or more than two selected from a monomer citric acid, citrateand glucose, the nitrogen source B is one or more than two selected from ethylenediamine, triethylamine, glycine and urea, and the passivator is selected from ammonia water and / or polyethylene glycol.According to the invention, the carbon nano fluorescent material prepared by the method is not influenced by salinity and is stable in fluorescence property in a seawater medium, and the fluorescenceintensity of the obtained product under the same test condition is obviously higher than that of seawater; the prepared fluorescent material has no condensed ring, does not contain benzene ring, andis environment-friendly; and the preparation method of the carbon nano fluorescent material is simple, easy to implement and low in cost, and has good economic and social benefits.

The invention discloses a sulphoaluminate self-fluorescent gelatinizing mineral. The sulphoaluminate self-fluorescent gelatinizing mineral is prepared from the following raw materials by weight: 25-35parts of calcium carbonate, 15-30 parts of barium carbonate, 5-10 parts of barium sulfate, 45-55 parts of aluminum oxide, 25-35 parts of calcium sulphate dihydrate, 0.5-1.5 parts of rare earth element, and 1-3 parts of high-molecular polymer. The invention further discloses a preparation method of the sulphoaluminate self-fluorescent gelatinizing mineral. The sulphoaluminate self-fluorescent gelatinizing mineral is prepared by doping and modifying the rare earth element, the burnability of the mineral in the solid-phase reaction process is obviously improved, the gelatinizing property of thegelatinizing mineral is further improved, the hydration activity is good, the compressive strength is high, and the anti-frost property is good.

The invention belongs to the technical field of quantum dots, and particularly relates to a preparation method of a carbon quantum dot. The preparation method of the carbon quantum dot comprises the following steps of providing saccharide carbon sources and ammonia salt; performing solid-phase reaction on the mixture of saccharide carbon sources and ammonia salt under the sealing condition at thereaction environment temperature higher than or equal to 120 DEG C. The preparation method of the carbon quantum dot has the advantages that the organic amine is not used as the nitrogen source, but the ammonia salt is used as the nitrogen source, so that the biological toxicity is low, the emission of waste liquid is avoided, the production cost is low, the operation is simple, the preparation technology of the material is simplified, and the hazard of raw material is decreased. The obtained nitrogen-doped carbon quantum dot material has the advantages that the Cd (cadmium), Te (tellurium) and other heavy metals are not contained; compared with the traditional quantum dot material, the application field is broader.

The invention discloses a metal complex of a double-cup[4]aromatic hydrocarbon derivative. The metal complex has a chemical structure as shown in formula II. The complex is small in toxicity, high inbiological compatibility, suitable for being covalently combined with biological molecules such as nucleic acid, peptide or proteins to form a fluorescent probe molecule with high fluorescent quantumrate, long fluorescent service life and low detection limit, suitable for detecting the biological molecules in cells, tissues or living bodies and wide in application prospect in the field of biological medicine. The invention discloses a synthetic method of the complex, provides various selection ways for the synthesis of the complex, is simple and easy in synthesizing a route, high in yield ofprepared complex and suitable for the mass production of the complex.

The invention belongs to the field of fluorescent functional materials, and particularly relates to a water-soluble silicon quantum dot and a preparation method thereof and application thereof in highsensitivity and high selectivity detection of p-nitrophenol. The key points of the preparation method are as follows: 3-aminopropyltriethoxysilane is added into ultrapure water to react for 10 min under the condition of 85 DEG C and vigorous stirring, then a paracetamol solution is added, and continuous stirring is performed for reaction for 5 hours. The preparation method of the silicon quantumdot is simple and convenient, the reaction conditions are mild, the quantum yield is high, the water solubility is good, and the silicon quantum dot can be stored for a long time, and the excellent fluorescence performance can be maintained even under the conditions of different pH values and different ionic strengths. The silicon quantum dot emits 495 nm fluorescence under 398 nm fluorescence excitation, and the p-nitrophenol can specifically quench the fluorescence of the silicon quantum dot. The silicon quantum dot disclosed by the invention has a good application prospect in the aspects offast and efficient, high selectivity and high sensitivity detection of p-nitrophenol.

The invention provides a special fluorescent anti-counterfeit material and a preparing method and application thereof. The fluorescent anti-counterfeit material comprises a compound shown in the formula (I), a stabilizer and / or macromolecule resin. The raw materials involved in the preparing process of the fluorescent anti-counterfeit material are wide in source; the special fluorescent anti-counterfeit material is high in synthesis yield and stable in fluorescence performance, and can be directly printed after being mixed with commercial printing ink, large-scale application and popularization of anti-counterfeit labels are facilitated, and the application prospect is wide. The structure of the formula (I) is shown in the following description.

The invention discloses nitrogen-sulfur co-doped biomass-based fluorescent carbon dots which are prepared from the following raw materials in parts by weight: 0.5-4 parts of a biological carbon source, 0.1-4 parts of a nitrogen source and 0.1-4 parts of a sulfur source by adopting a hydrothermal method in one step. The problem that existing fluorescent carbon dots are harsh in preparation conditions and low in fluorescent quantum yield is solved, the operation is easy, the raw material cost is low, and the prepared nitrogen-sulfur co-doped cellulose-based fluorescent carbon dots are high in fluorescent quantum yield, stable in fluorescence performance, good in biocompatibility and low in toxicity, and the nitrogen-sulfur co-doped cellulose-based fluorescent carbon dots can be applied to the fields of biological imaging and iron ion detection.