1087 results about "Upconversion luminescence" patented technology

The present relates in general to upconversion luminescence ("UCL") materials and methods of making and using same and more particularly, but not meant to be limiting, to Mn2+ doped semiconductor nanoparticles for use as UCL materials. The present invention also relates in general to upconversion luminescence including two-photon absorption upconversion, and potential applications using UCL materials, including light emitting diodes, upconversion lasers, infrared detectors, chemical sensors, temperature sensors and biological labels, all of which incorporate a UCL material.

The invention belongs to the field of photocatalytic materials, in particular relates to a novel red light or infrared light catalytic material which comprises an up-conversion material and a semiconductor material. In the invention, a semiconductor photocatalytic material and a red light / infrared-ultraviolet up-conversion luminescent material are combined, and the up-conversion material is used for absorbing red light / infrared light and emitting ultraviolet light, thereby activating the semiconductor photocatalytic material and realizing the infrared light catalysis. By modifying and improving the semiconductor in the composite material, the photocatalytic activity of the material can be further improved. The invention expands the wavelength range of the excitationlight required by photocatalytic reaction, breaks the limit that the photocatalytic reaction can be activated only by ultraviolet light and shortwave visible light, improves the utilization ratio of sun light in the photocatalytic reaction, and can be widely applied to the photocatalytic degradation of organic pollutants in water by using red light, infrared light and sun light.

The invention belongs to the technical field of nanometer biological materials, and particularly relates to an 800nm excitation-based up / down conversion dual-mode fluorescent nanomaterial for Nd<3+> sensitization and a synthesis method thereof. The synthetic up / down conversion dual-mode fluorescent nanomaterial for Nd<3+>sensitization designed by the invention has a multi-layer core-shell structure, and comprises a down conversion luminous layer, an up conversion luminous layer, an isolation layer and a passivation layer. Different layers of the material synergistically play respective different roles, and meanwhile, the dual-mode fluorescent probe with up conversion fluorescence and down conversion fluorescence is finally achieved under an 800nm of excitation light with a low-heat effect. The up conversion excitation light is expanded to about 800nm from 980nm by Nd<3+>, Yb<3+> and Er<3+>-doped NaGdF4:Nd, Yb, Er up conversion layer due to introduction of Nd<3+>, and the fluorescent process from a near infrared light to a visible light is achieved. The process meets the requirements of an in-vitro fluorescent probe. In addition, the typical down conversion fluorescence from the near infrared light to a far infrared light is also achieved in one nanoparticle due to the synergistic effect of the NaGdF4:Nd core.

The invention provides a method of improving luminous efficiency of a rare earth-doped up-conversion luminescence nanometer material through changing the usage of a ligand. According to the method, the synthesis adopts a hydrothermal-solvothermal method, an organic ligand is an organic compound such as monocarboxylic acid, dicarboxylic acid or polycarboxylic acid, and amine, the molar ratio of rare earth ions to the ligand is 2:1-1:100, the molar ratio of NaOH to the ligand is 0:1-1:1, water / alcohol, water / n-propanol alcohol, water / isopropyl alcohol, water / n-butyl alcohol, water / acetone or water / ethylene glycol is used as a solvent, the temperature ranges from 180-240 DEG C, the reaction time is 2-24h, and the F<-> / Re value ranges from 4-12. With the method, the problems of selecting various ligands for synthesizing the up-conversion luminescence nanometer material, improving the luminous efficiency of the rare earth-doped up-conversion luminescence nanometer material, synthesizing the water-soluble up-conversion luminescence nanometer material, and the like can be mainly solved.

The invention discloses a lutetium-aluminum carbuncle basic transparent ceramic and preparing method in the crystalline ceramics domain, which is characterized by the following: the crystalline ceramic is made up with Lu3-xRExAl5O12, wherein 0 C04B 35 / 44 C04B 35 / 622 2 5 2 2006 / 4 / 7 1837142 2006 / 9 / 27 100455536 2009 / 1 / 28 2009 / 1 / 28 2009 / 1 / 28 Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 Liu Xuejian Li Huili Huang Liping pan zhen 31002 Shanghai Patent Agency of the Chinese Academy of Sciences No.319 Yueyang Road, Shanghai 200031

The present relates in general to upconversion luminescence (“UCL”) materials and methods of making and using same and more particularly, but not meant to be limiting, to Mn2+ doped semiconductor nanoparticles for use as UCL materials. The present invention also relates in general to upconversion luminescence including two-photon absorption upconversion, and potential applications using UCL materials, including light emitting diodes, upconversion lasers, infrared detectors, chemical sensors, temperature sensors and biological labels, all of which incorporate a UCL material.

The invention belongs to the technical fields of preparation and application of a bioluminescent marker, and particularly relates to a strong near infrared up-conversion luminous bioluminescent nanoparticle of a Yb and Ho ion di-sensitized Tm ion and an application thereof. Through energy transmission among Yb / Ho / Tm in the up-conversion luminous material, higher-efficiency 800-nanometer near infrared up-conversion light transmission can be obtained under the induction of near infrared light of 900-1,064 nanometers. The nanoparticle has the advantages that: excited light and emitted light at positioned at a range of 750-1,000 nanometers of an optical window of a biological tissue, and enhanced near infrared up-conversion light can be emitted at a position of 800 nanometers. The near infrared light and visible light in the range have higher penetrating power in organisms, and the functions of fluorescence detection, tracing and the like of higher-layer biological tissues in organisms can be realized. The near infrared luminous strength of the obtained material close to the position of 800 nanometers is enhanced greatly, and the material is easy to detect, and has a simple preparation process.

The invention discloses a potassium-sodium niobate based oxide up-conversion luminescent material with a chemical formula of (Na0.5+sigmaK0.5-yAy)1-x-zMxYbzNbO3:Phi C or (Na0.5-yAyK0.5+sigma)1-x-zMxYbzNbO3: Ph iC, wherein M is selected from one or more of Li, Na, K, Tl and Ag; C is selected from one or more of Li, Na, K, Tl and Ag; A is one or more of K, Na and Li; a value range of x is not smaller than 0.00001 and not bigger than 0.15, the value range of y is not smaller than 0 and not bigger than 0.5, the value range of z is not smaller than 0 and not bigger than 0.35, the value range of sigma is not smaller than 0 and not bigger than 0.1 and the value range of Phi is not smaller than 0 and not bigger than 0.1. The luminescent material disclosed by the invention further has up-conversion luminescent characteristic in addition to piezoelectric performances, ferroelectric performances and dielectric performances, belongs to photoelectric multifunctional materials, and not only can be applied to the piezoelectric field, but also can be applied to the sensor field, the information storage field, the biological detection field and the biomedical field.

The invention discloses fluorescent salix mongolica regenerated cellulose fibers and a preparation method thereof. The preparation method comprises the following steps: peeling off salix mongolica, crushing, sieving, drying and cooling to prepare salix mongolica wood powder; extracting salix mongolica cellulose by adopting an ethanol-acid mixed solution; treating the salix mongolica cellulose by processes of steaming, bleaching and the like to prepare salix mongolica pulp; filtering, decompressing and de-foaming water-soluble up-conversion nano particles and the salix mongolica cellulose to obtain a spinning solution which is uniformly mixed; and spinning the spinning solution by a condensation bath, drafting and molding, refining and drying to obtain the fluorescent salix mongolica regenerated cellulose fibers. A preparation process of the water-soluble up-conversion nano particles comprises the following steps: firstly, synthesizing hexagonal-phase up-conversion luminous nano particles UCNPs by adopting a high-temperature thermal decomposition method; treating the UCNPs with nitrosonium tetrafluoroborate NOBF4, and replacing oleic acid molecules on the surface; finally, reacting with a hydrophilic hyperbranched polymer to obtain the water-soluble up-conversion nano particles. According to the fluorescent salix mongolica regenerated cellulose fibers, the water-soluble up-conversion nano particles and the salix mongolica regenerated cellulose are used as raw materials and are subjected to efficient blending and wet-process spinning to prepare the regenerated cellulose fibers with the excellent fluorescent performance.

The invention provides an OLED display device, a manufacturing method thereof, a color film substrate and a manufacturing method thereof, and relates to the technical field of displaying. On the premises of low cost and high display stability, the display brightness of the display device is improved, and the display color gamut is increased. The OLED display device comprises a TFT array substrate; a luminescent structure layer arranged on the TFT array substrate, wherein the luminescent structure layer emits out infrared light; and a light conversion layer arranged on the luminescent structure layer, wherein the light conversion layer comprises a plurality of pixel regions, each pixel region is internally provided with at least a red light conversion unit, a green light conversion unit and a blue light conversion unit. The red light conversion unit is formed by an upper conversion luminescent material which emits red light after excited by infrared light; the green light conversion unit is formed by an upper conversion luminescent material which emits green light after excited by infrared light; and the blue light conversion unit is formed by the upper conversion luminescent material which emits blue light after excited by the infrared light. The OLED display device is used for displaying images.

The invention provides a photothermal conversion nanometer material. The chemical formula of the photothermal conversion nanometer material is AR1-x-yF4, wherein Ybx and Ery are doped in the AR1-x-yF4, A is at least one of Li, Na or K, R is at least one of Y, Gd, Lu, or Nd, x is less than or equal to 0.6 and greater than or equal to 0.01, and y is less than or equal to 0.1 and equal to or greater than 0.01; the particle size of the photothermal conversion nanometer material particles is within the wavelength range of 5-40nm. The photothermal conversion nanometer material can emit visible light with the range of 520-660nm under the excitation effect of the near infrared laser with the wavelength range of 750-1100nm, while a temperature rise of about 5-300 DEG C can be achieved, and since the ratio of the emission band with the wavelength of 525nm and emission band with the wavelength of 545nm in the emitted light and the temperature meet a good exponential relationship, the temperature detection function can be realized. The photothermal conversion nanometer material has the significant characteristics that the material can absorb near-infrared laser with the wavelength range of 750-1100nm and the photothermal conversion, upconversion luminescence and temperature detection functions are achieved simultaneously. Another object of the invention is to provide a preparation method and application method of the photothermal conversion nanometer material, and the preparation method is simple, easy to operate, free of pollution and low in cost.

The invention belongs to the technical field of fluorescence nano-materials, and particularly relates to an upconversion crystal nano-material for infrared ray excited red-green-blue three-color orthogonal fluorescence transmission and a preparation method thereof. The nano-material comprises five types of shells, including an upconversion luminous center core, two upconversion luminous shells, an inert isolation layer, an energy transfer layer and an energy absorption layer, wherein the upconversion luminous center core and the energy absorption layers are used for absorbing exciting lights having specific wavelengths; the energy transfer layer is used for transferring energy between the energy absorption layer and a visible light luminous layer; the inert isolation layer is used for isolating each luminous center through an inert material inhibiting energy transfer, so that the fluorescence process of the luminous centers are not impacted one another; and the thickness of each energy absorption layer is adjusted to filter infrared exciting light strengths, so that each energy absorption layer can be used for absorbing energy of infrared exciting lights having different wavelengths respectively, and the energy can be finally transferred to corresponding unused luminous centers. The upconversion crystal nano-material realizes independent fluorescence transmission of red-green-blue three-primary colors, and can be used in the field of volumetric three-dimensional colorful display.

The invention discloses a Cs3LaCl6 nanocrystalline-containing transparent chalcohalide glass ceramic and its preparation. The glass ceramic comprises: 40-60 mol% of GeS2; 25-35 mol% of Ga2S3; 2-8 mol% of La2S3; 2-8 mol% of LaCl3; 10-20 mol% of CsCl; and 0.01-0.2 mol% of Re2S3, wherein Re represents a rare earth ion (such as Nd, Er). The preparation process of the glass ceramic consists of melt quenching preparation of precursor glass and subsequent crystallization heat treatment of the precursor glass. By component exploration, the transparent chalcohalide glass ceramic containing the single Cs3LaCl6 nanocrystalline can be prepared. The nanocomposite material has excellent properties of under near-infrared transfer and visible up-conversion luminescence, and has potential application in near infrared lasers, optical fiber amplifiers, three-dimensional solid-state display and other fields.

Methods, apparatus and systems for an up-converter resonant cavity light emitting diode device includes a semiconductor light source, an up-converter to form the light emitter with up-converting materials and an electrical source coupled with the semiconductor light source for providing electrical energy to the semiconductor light source to provide a desired wavelength emitted light. The semiconductor light source is a resonant cavity light emitting diode or laser that emits an approximately 975 nm wavelength to provide electrical and optical confinement to the semiconductor light source to form a resonant cavity up-converting light emitting diode (UC / RCLED). Rows and columns of electrodes provide active matrix addressing of plural sets of UC / RCLEDs for display devices. The up-converter resonant cavity light emitting diode device has applications in head mounted projection display optical system using spectrally selective beam splitters to eliminate spectral overlap between colors and to combine the red, green and blue beams.

The invention belongs to the field of up-conversion luminescence materials, in particular relates to a nanogold modified enhanced up-conversion luminescence composite material and a preparation method thereof. The nanogold modified enhanced up-conversion luminescence composite material is characterized in that nanogold particles and an up-conversion luminescence nanomaterial are combined and irradiated by exciting light to realize high up-conversion luminescence efficiency from a long wave region to a short wave region by utilizing the local field enhancement effect of the nanogold particles,and the luminescence efficiency can be up to 500 times at most, therefore, the defect of low luminescence efficiency of the up-conversion nanomaterial is effectively overcome. The nanogold modified enhanced up-conversion luminescence composite material has a general formula: AReF4: Ln<3+> / Au or DF2: Ln<3+> / Au, wherein A is a metal element, such as Na, Li, K, or the like, and D is a metal element of Ca, Ba, or the like; Re is one of rare earth elements comprising Y, Gd, Lu, and the like; and Ln<3+> is one of lanthanide doped ions comprising Yb<3+>, Tm<3+>, Er<3+>, Ho<3+>, Gd<3+>, Eu<3+>, and the like. The nanogold modified enhanced up-conversion luminescence composite material provided by the invention has remarkably improved up-conversion luminescence efficiency, is easy to detect and hassimple process equipment.

The invention belongs to the technical field of nano biological materials and particularly relates to a single-emission up-conversion nano fluorescent probe and a synthetic method thereof. The fluorescent probe is a nanocrystal with a structure comprising a core layer and three shell layers and comprises an up-conversion luminescence center core layer, an inert shell layer, a silicon dioxide shell layer and a dye-doped silicon dioxide shell layer; an active ion doped rare earth nanocrystal is arranged at the up-conversion luminescence center, and the inert shell layer completely covers the luminescence core; the silicon dioxide shell layer can avoid fluorescence resonance energy transfer between the up-conversion luminescence center and dye; the dye-doped silicon dioxide shell layer is used for removing unwanted up-conversion emission peaks and reserving specific up-conversion emission peaks, and single-emission up-conversion fluorescence is realized. By means of the probe and the method, multiple signal modules can be detected in situ simultaneously, and further, the detection sensitivity and the accuracy are improved. The fluorescent probe has a broad application prospect in the aspects of protein expression, high throughput screening of biological samples, multi-channel biological detection, disease diagnosis and the like.

The invention relates to a rare-earth doped bismuth titanate up-conversion luminescence nanometer crystal material which relates to a bismuth titanate luminescence nanometer crystal material. The invention solves the problem of low luminous intensity of the rare-earth doped bismuth titanate up-conversion luminescence nanometer crystal material. The rare-earth doped bismuth titanate up-conversion luminescence nanometer crystal material is obtained by doping Er, Er / Yb, Yb / Tm and Er / Yb / Tm to the bismuth titanate matrix by a sol-gel method. The up-conversion luminescence nanometer crystal material can realize up-conversion luminescence of different colours of red, green, yellow, blue and white under the excitation of infrared radiation with the wavelength of 980nm and has high luminous intensity. The rare-earth doped bismuth titanate up-conversion luminescence nanometer crystal material can be widely applied in the fields of infrared radiation detection, anti-counterfeit, bimolecular fluorescent mark, and the like.

The invention relates to a preparation method of a water-soluble rare earth up-converting luminescence nano particle modified by amino acid. The method is characterized by comprising the following steps: removing oleic acid on the surface of the NaYF4:Yb / Er up-converting nano particle by using a solvent extraction method in the acidic environment with pH 3-5 on the basis of the NaYF4:Yb / Er up-converting nano particle which is modified by oleic acid and has high light intensity; and functionalizing the rare earth up-converting particle without oleic acid by using amino acid to obtain the water-soluble rare earth up-converting luminuscence nano particle. The prepared rare earth up-converting nano particle not only has the high light intensity of the NaYF4:Yb / Er up-converting nano particle modified by oleic acid, but also is completely water-soluble, and the surface of the rare earth up-converting nano particle has amino groups and carboxyl groups which can be used for being crosslinked with biomolecules. The preparation method is simple and easy to operate and has a good application prospect.

The present invention relates to rare earth upconversion nanoparticles, a preparation method and uses thereof, wherein the rare earth upconversion nanoparticles sequentially comprise an activator shell layer, an energy transfer agent shell layer and a sensitizing agent shell layer from inside to outside, each layer contains Yb<3+>, and the doping concentration of Yb<3+> is gradually reduced from inside to outside. According to the present invention, the ytterbium ion doping concentration gradient is set to effectively transfer the excitation state energy of the sensitizing agent to the activator, such that the upconversion luminescence quantum yield of the rare earth upconversion nanoparticles is effectively improved and achieves 0.22%, and the 800 nm continuous laser excitation at the excitation light source intensity of 2W / cm<2> is achieved; and the rare earth upconversion nanoparticles can produce strong upconversion luminescence under the infrared LED light source excitation, and the potable detection equipment based on the rare earth upconversion nanoparticle luminescence probe can be designed by using the unique packaging and array technology of the infrared LED light source so as to further expand the application of the upconversion luminescence material in the biomedical field.

The invention discloses a composite upconversion nanoprobe with multicolor luminescent spectrums and a preparation method and an application of the composite upconversion nanoprobe. PEI-NaYF4:Yb,Tm and PAA-NaYF4:Yb,Er of which the mass ratio is 3:1 are evenly mixed, so that the composite upconversion nanoprobe with the multicolor luminescent spectrums is obtained. The nanoprobe is made of a rare-earth-based upconversion luminescent nano-material and has the multiple visible luminescent zone spectrums, and therefore proportional fluorescence visual detection can be achieved. According to TNT test paper prepared by using the nanoprobe as a host material, under excitation by a light source with the wavelength being 980 nm, whether TNT exists or not is judged by observing whether a fluorescence color of the test paper changes or not. The upconversion luminescent nano-material is excited on the basis of the near-infrared light source, background fluorescence interference can be well overcome, and therefore detection sensitivity can be improved to a great extent. A synthetic method of the host material is simple and practicable, a substrate of the test paper is low in price, the TNT test paper and the excitation light source thereof are convenient to carry, operation is simple, reliability is high, and therefore the TNT test paper is very suitable for a security check site.

The invention discloses a preparation method of citrate modified NaYF4:Yb,Er / Mn up-conversion luminescent nano material, a hydrogen peroxide or uric acid detection method and applications. The preparation method comprises the following steps: 1) stirring alkali, water, oleic acid, C1-C3 alcohol, a manganese source, a ytterbium source a yttrium source, an erbium source and NaF, and then carrying out hydrothermal reaction and centrifugal separation to obtain OA-NaYF4:Yb,Er / Mn UCNPs; and 2) dispersing OA-NaYF4:Yb, Er / Mn UCNPs in alcohol, and then carrying out ligand exchange reaction with a trichloromethane and citrate solution to obtain the citrate modified NaYF4:Yb,Er / Mn up-conversion luminescent nano material. The citrate modified NaYF4:Yb,Er / Mn up-conversion luminescent nano material has the advantages of low detection limit, high sensitivity and good selectivity to hydrogen peroxide or uric acid detection, so that the material can be used for detecting uric acid in serum.

The invention discloses a multicolor infrared upconversion luminous material and a preparation method thereof. The material has a chemical composition formula: RE2-x-y(WO4)3: xLn,yYb, wherein x is between 0.02 and 0.2; y is between 0.2 and 0.6; Yb<3+> is used as a sensitizing agent, absorbs infrared photons and transfers energy to Ln in order that Ln ions irradiate; and under 980nm laser pumping, the material emits red light, green light, blue light or white light. In preparation, according to stoichiometric ratio, high-purity raw materials of rare earth oxide and tungsten trioxide are ground, are evenly mixed, are presintered for 3 to 10 hours in air at a temperature of between 700 and 900 DEG C, are ground, are sintered for 4 to 10 hours in the air at a temperature of between 1,100 and 1,200 DEG C and are naturally cooled to the room temperature, so as to obtain the product. In the preparation process, no organism is used; and no harmful exhaust gas is produced. The synthetic process is carried out in the air; and the preparation method has low equipment requirement and a simple process.

The invention discloses an up-conversion-nanocrystal-based stimulated depletion super-resolution optical microscopic method and an up-conversion-nanocrystal-based stimulated depletion super-resolution optical microscopic system. An up-conversion nanocrystal and the stimulated emission depletion super-resolution fluorescence micro-imaging technique are combined, a super-resolution multiphoton fluorescence signal generated by stimulated emission depletion of an up-conversion luminescent nanometer material labeled sample is detected, a continuous low-power steady-state stimulated depletion process of multiphotons excited by a laser is realized and the simple and effective three-dimensional super-resolution imaging effect having low cost, low complexity and high resolution can be achieved. The stimulated emission depletion super-resolution optical micro-imaging system composed of a depletion light generating module, an exciting light generating module, a plurality of dichroscopes, a multiphoton micro-scanning module and a photoelectric detection module is built based on the method, and a simple and effective real-time dynamic three-dimensional image having low cost, low complexity and high resolution can be acquired.

The invention belongs to the technical field of a nano up-conversion luminescent material, in particular relates to a preparation method for a small-sized NaYF4 nano substrate material with a hexagonal phase by inducement with rare earth nano crystal nucleus. In the method, rare earth ions are doped in the NaYF4 nano substrate material so as to obtain a nano material with a low up-conversion luminescence threshold and high luminescence strength. In the method, the small-sized beta-NaYF4 nano substrate material is generated by inducement with a hydrothermal (solvent) process in the presence ofrare earth fluoride nano crystal nucleus, wherein the size of the particle is from 20nm to 200nm, and distribution of the size is even. According to the invention, a preparation method of the small-sized NaYF4 nano substrate material with the hexagonal phase is expanded, and the problem that the NaYF4 nano substrate material, especially water-soluble NaYF4 nano substrate material is difficultly generated at low temperature, is solved. By using the nano up-conversion luminescent material, the demand on biological fluorescent identification probes and disease diagnosis and treatment materials is met, and a foundation is established for the practicable application of the up-conversion luminescent material.

The invention relates to a preparation method and application for a multifunctional nanometer diagnosis and treatment agent integrating light emitting / CT / MR multi-mode imaging and tumor hyperthermia. The multifunctional nanometer diagnosis and treatment agent comprises up-conversion luminescence nano-particles, a silicon dioxide layer, near-infrared photothermal conversion agent particles and sulfhydryl functionalization polyethylene glycol, wherein the up-conversion luminescence nano-particles have the performance of near-infrared light emitting / CT / MR three-mode imaging; the surfaces of the up-conversion luminescence nano-particles are wrapped with the silicon dioxide layer; the near-infrared photothermal conversion agent particles are in electrostatic adsorption on the surface of the silicon dioxide layer; the sulfhydryl functionalization polyethylene glycol is grafted onto the surfaces of the near-infrared photothermal conversion agent particles. The multifunctional nanometer diagnosis and treatment agent provided by the invention can integrate light emitting / CT / MR multi-mode imaging and the tumor hyperthermia into a whole, and through the stimulation of a single wave band, the light emitting imaging and tumor hyperthermia can be achieved simultaneously.

The invention relates to an Er<3+>:YAlO3 / TiO2-loaded photocatalyst and a preparation method thereof. The catalyst comprises the main components of Er<3+>:YAlO3, TiO2 and active carbon, wherein the Er<3+>:YAlO3 powder and TiO2 powder are loaded to the surface of the spherical active carbon, and the mass ratio of the Er<3+>: YAlO3 powder to the TiO2 powder is 1:4. A combination mode comprises the following steps of firstly dispersing Er<3+>:YAlO3 and TiO2 in the molar ratio of 1: 5 into anhydrous ethyl alcohol; then adding the active carbon to the anhydrous ethyl alcohol in the mass ratio of 1:4; magnetically stirring for 30min; and then drying out of sun at 80 DEG C to obtain a final product. In the invention, an up-conversion luminescence agent Er<3+>:YAlO3 containing the rare earth Er is selected to be doped into the TiO2 powder, a mixture of the up-conversion luminescence agent Er<3+>:YAlO3 and the TiO2 powder is loaded on the surface of the spherical active carbon to degrade organic pollutants in the irradiation of visible light. The Er<3+>:YAlO3 / TiO2-loaded photocatalyst achieves the purpose of treating wastewater by utilizing the visible light, greatly saves energy sources, gives full play to TiO2 catalytic activity, is convenient to be naturally separated from treated water at the same time and reduces the utilization cost.

The invention belongs to the technical field of nanometer biological materials and particularly relates to an infrared-excited fluorescence-lifetime-adjustable up-conversion nanocrystal material and a preparing method thereof. The fluorescence nanometer material is a core-shell structure nanocrystal material with one core and two shell layers, and is composed of the up-conversion fluorescent center core, the energy transmission layer and the energy absorption layer. The up-conversion fluorescent center core absorbs exciting light with the specific wavelength and emits visible light; the energy transmission layer transmits energy between the energy absorption layer and a visible light emitting layer, and the fluorescence lifetime of the material is regulated by changing the thickness of the energy transmission layer; the energy absorption layer absorbs the energy of infrared-excited light and transfers the energy to the energy transmission layer. Through the design of the three-layer structure, the energy transmission process from Nd<3+ >to Yb<3+> to Tm<3+> and the energy transmission process from Nd<3+> to Yb<3+> to Er<3+> are achieved, and in addition the fluorescence lifetime of the material can be regulated and controlled just by changing the thickness of the middle layer. The material can be applied to the fields of analysis and detection.

The invention discloses a microfluidic system and method for detecting and screening single beam biological cells. The system comprises a detection device, an optical tweezers device, a microfluidic chip, an electric objective table and an objective lens. The method comprises the steps of labeling cells to be detected by using an up-conversion luminescence nanometer material to obtain problem cells with up-conversion luminescence nanometer probe labels and normal cells without labels; carrying out laser scanning on all cells, wherein the problem cells with the up-conversion luminescence nanometer probe labels emit up-conversion light on the condition of being induced by near-infrared band laser, and once a detector detects an up-conversion fluorescence signal, the cells are screened out by using an optical tweezers technology; and finally, detecting, counting and separating the problem cells. The system and method are reduced in cost and increased in signal to noise ratio of the signals to be detected, has the great technical development application space and wide market prospect, and is suitable for structure microminiaturized devices for cancer cell diagnosis and control structures based on microfluidic chips.