189 results about "Photobleaching" patented technology

The invention provides a photosensitive resin composition containing a photobleaching aminomethyl anthracene photosensitizer and application thereof.The structural main body anthracene ring of the photosensitizer introduces an aminomethyl functional group to the 9th and / or 10th site: through introduction of the aminomethyl functional group, while the electron cloud density of polycyclic aromatic hydrocarbon is maintained, the maximum absorption wavelength is subjected to red shift, and the photosensitive resin composition is especially suitable for a 405nm illumination system; the initiation efficiency is obviously improved; the exposure energy is reduced; compared with an existing DBA type photoinitiator, the problem of alkoxy carbon-oxygen bond breakage caused by p-pi conjugation of DBA is avoided, generation of small molecule fragments is effectively inhibited, defects are reduced, and the yield is increased. In addition, compared with DPHA and DAcOA, the photosensitizer also shows better solubility and formula compatibility. The preparation method has the characteristics of simple preparation process and low cost, and can be widely applied to the photocuring fields of dry films, paints, coatings, printing inks, forming materials and the like.

The invention provides a diepoxy alkoxy anthracene photosensitizer, and relates to the field of photopolymerization. The invention further comprises a light-cured resin composition containing the diepoxy alkoxy anthracene photosensitizer, a light-sensitive dry film containing the diepoxy alkoxy anthracene photosensitizer and application of the light-cured resin composition and the light-sensitive dry film. The photosensitizer provided by the invention has the characteristics of low migration before curing and low precipitation after curing, and is excellent in photosensitive property and high in photobleaching efficiency; the polymer can be widely applied to the fields of photopolymerization and photocuring of dry films, paints, coatings, printing ink, forming materials and the like; in a photosensitive dry film, the photosensitizer cannot migrate to a polyethylene film, and when an electroplating process is carried out after exposure and development, fragments cannot be separated out to pollute electroplating liquid, so that undesirable phenomena of short circuit, open circuit and the like of an anti-corrosion pattern are avoided, and the yield of a product is remarkably improved.

The invention provides a photosensitive resin composition containing an anthracene methyl quaternary ammonium salt photosensitizer and application of the photosensitive resin composition, a structural main body anthracene ring of the photosensitizer is introduced into methylene substituted by a quaternary ammonium group at a position 10 and / or a position 9, and an acid radical or halogen is adopted as an equilibrium anion; compared with a commercially available anthracene photosensitizer, the photosensitizer has excellent fat solubility and good water solubility through introduction of the quaternary ammonium salt on the premise that the photobleaching property is retained, great potential is brought to formula design of the photosensitive composition, and development waste in a later development process can be greatly reduced; the method can be widely applied to the photo-curing fields of dry films, paints, coatings, printing ink, forming materials and the like.

The invention belongs to the field of fluorescence detection, and particularly relates to a ratio-type fluorescent nanoprobe for specifically detecting tetracycline antibiotics as well as a preparation method and an application method of the ratio-type fluorescent nanoprobe. The nano-probe is a europium modified zinc gallium germanate nano-material, and is prepared by amino modification, citric acid modification and europium modification of the zinc gallium germanate nano-material. The probe can be specifically combined with tetracycline antibiotics; the fluorescent probe has two different fluorescence emission intensities, so that interference can be effectively eliminated, and the detection accuracy is high. And the synthesis method is simple and low in cost. The ratio type fluorescent nanoprobe provided by the invention also can realize the change of different colors under an ultraviolet lamp, can realize quantitative visual detection of tetracycline by combining the RGB value and the tetracycline concentration change, and can realize rapid on-site detection of tetracycline in a sample without the help of a fluorescent instrument. The tetracycline fluorescent probe is stable in optical performance, not prone to photobleaching, high in tetracycline recognition capacity, wide in response range (0.2-70 [mu] M) and low in detection limit, and has remarkable industrial application potential.

The invention provides a rare earth complex as well as a preparation method and application thereof. The chemical general formula of the rare earth complex is (Ln < 1x > Ln < 2y > Ln < 31-x-y >) (A) m (B) n, the rare earth complex provided by the invention has a self-assembly behavior, spherical nanoparticles can be formed through molecular aggregation, under ultraviolet irradiation, internal ligand molecules are better protected, the photobleaching process of the rare earth complex under natural conditions is slowed down, and the rare earth complex has better stability and higher weather resistance in the natural environment.

The invention discloses a microscopic imaging device and a super-resolution microscopic imaging method, and the device comprises a sample stage which is used for containing a sample; the laser is used for emitting laser; the first digital micromirror is used for receiving the laser and generating diffracted light; the light condensing unit is used for condensing the plurality of diffracted light to form structured light so as to excite fluorescence carrying sample information; the second digital micromirror is used for receiving the fluorescence and converting the fluorescence into a random binary coding image; the image acquisition unit is used for receiving images and transmitting the images to the processing unit; the processing unit is used for reconstructing a microscopic super-resolution image based on the plurality of random binary coding images; the first digital micromirror, the second digital micromirror and the image acquisition unit are in communication connection, and the second digital micromirror controls the grating pattern conversion frequency of the first digital micromirror and controls the image acquisition frequency of the image acquisition unit. The biological cell sample can be protected from being damaged by phototoxicity and photobleaching performance, and super-resolution imaging in the structured illumination obvious microsystem is achieved.

The invention belongs to the technical field of industrial silane preparation, and provides a natural silane rotor and a preparation method and application thereof.The preparation method comprises the steps that a pyridoxal phosphate solution and a 4-amino ethyl cinnamate solution are mixed and then react to obtain pyridoxal phosphate cinnamyl ester; and mixing the pyridoxal phosphate cinnamyl ester solution and the amino silane solution, and reacting to obtain the natural silane rotor. The silane rotor has a good conjugated structure, is stable in chemical structure, can be stored for a long time, is good in light stability, and is not liable to cause a photobleaching phenomenon. Besides, conjugated single and double bonds capable of freely rotating exist in the molecular structure, a typical flexible intramolecular rotation characteristic is presented, the conjugated structure can freely rotate in a dilute solution, a surface sightseeing signal is weak, the free rotation phenomenon is limited in a thick solution, the surface sightseeing signal is strong, and the surface sightseeing signal is strong. Therefore, the device can be used as a molecular tool for monitoring the change of the thin consistency of the silane, and can provide real-time, lossless and visual detection support for the development of a silane modulation process.

The invention provides fluorescent carbon dots and fluorescent hydrogel based on solvent stimulation response discoloration and a preparation method and application of the fluorescent carbon dots and the fluorescent hydrogel, and belongs to the technical field of fluorescent materials and information encryption. The preparation method of the fluorescent carbon dots comprises the following steps: mixing a biomass carbon source and a solvent, and performing solvothermal reaction to obtain the fluorescent carbon dots, the biomass carbon source comprises one or more of buxus buxus, oriental cherry leaves, fructus forsythiae leaves and oak leaves; the solvent is ethanol. The biomass carbon dots are low in toxicity, excellent in optical stability and photobleaching resistance and high in ionic strength; the fluorescent carbon dots have double emission peaks of red light and blue light / green light, are different from single fluorescent carbon dots, and can provide more fluorescent information storage density for a fluorescent gel-based information orientation encryption system. The fluorescent color of the fluorescent hydrogel can be stably switched in an ethanol / water solvent, the gel structure is stable, the information storage capacity is improved, and a fluorescent hydrogel-based information anti-counterfeiting encryption system is promoted to develop towards multiple dimensions.

The present invention provides a photosensitive resin composition containing a photo-bleachable aminomethyl anthracene photosensitizer and its applications. An aminomethyl functional group is introduced at the 9- and / or 10-positions of the anthracene ring, which is the main structure of the photosensitizer. By introducing the aminomethyl group, while maintaining the electron cloud density of the polycyclic aromatic hydrocarbon, the maximum absorption wavelength is red-shifted, especially suitable for the 405 nm light irradiation system, significantly improving the initiation efficiency and reducing the exposure energy. Compared with the existing DBA-type photoinitiators, the problem of the cleavage of the alkoxy carbon-oxygen bond caused by p-π conjugation in DBA is avoided, effectively inhibiting the generation of small molecule fragments, reducing defects and improving the yield. Compared with DPHA and DAcOA, this photosensitizer also exhibits better solubility and formulation compatibility. The present invention has the characteristics of simple preparation process and low cost, and can be widely applied to the field of photocuring such as dry films, paints, coatings, inks and molding materials.

Provided herein are fluorescently-labeled nucleotide conjugates for nucleic acid analysis. Also provided are reagents used for forming binding complexes between a fluorescently-labeled nucleotide conjugate and a target nucleic acid sequence in the presence of one or more reagents disclosed herein. Binding complexes can be detected in the presence of the one or more reagents. For example, the one or more reagents may contain a photobleaching reducing agent configured to reduce photobleaching resulting from use of the fluorescently-labeled nucleotide conjugate to form the binding complex in a nucleic acid analysis. Such nucleic acid analysis may be used to identify sites of nucleobase binding or incorporation between the target nucleic acid sequence and one or more nucleotide moieties of the fluorescently-labeled nucleotide conjugate in a nucleic acid sequence reaction.

Method for single molecule localization microscopy (SMLM) based on conventional fluorescent binder probes, including primary or secondary antibodies, that are applied in a gradual stepwise fashion to a fixed biological sample. In each step of the process, a low dose of the probe is applied in solution to the fixed biological sample to sparsely label target epitopes followed by sample washing to remove the free probe. The remaining bound fluorescent probes that are sparsely distributed over the sample are then imaged until they are photobleached. The high light collection efficiency from each probe in this approach (limited only by photobleaching) enables few Ångstrom lateral resolution and few nm axial resolution. Photobleaching of the probes at the end of each step generates a clean slate for application of the next step in the process, as well as the possibility for applying one or more probes in a consecutive fashion to the same sample for serial SMLM.

The invention relates to the technical field of nano materials and biomedical engineering, and discloses a dye-sensitized rare earth up-conversion luminescent nano material as well as a preparation method and application thereof. The dye-sensitized rare earth up-conversion luminescent nano-material comprises a rare earth doped up-conversion nano-particle core, an unsaturated fatty acid salt self-assembled shell layer and a near-infrared dye modified on the surface of the rare earth doped up-conversion nano-particle. The unsaturated fatty acid salt coating layer endows the material with excellent water dispersibility through a hydrophilic group; a hydrophobic chain segment and an unsaturated double bond can effectively block water and oxygen permeation and quench singlet oxygen, so that the photobleaching half-life period of the material is increased by 86.7 times or more compared with that of a conventional coating material, and the light stability is excellent; the material successfully realizes efficient up-conversion luminescence under excitation of a low-power near-infrared light emitting diode (NIR LED, the power density of which can be as low as 100mW / cm < 2 >), and thoroughly gets rid of dependence on a high-cost and high-risk laser.

This invention relates to aggregation-induced emission probes with specific responses to tumor markers and their applications, belonging to the field of biochemistry. This invention utilizes molecular structure modulation to prepare a series of molecules possessing large Stokes shifts, resistance to photobleaching, near-infrared II (NIR-II) emission, and aggregation-induced emission properties. Different self-eliminating groups are attached to the dimethylamino group of the molecule via quaternization or to the pyridine group via pyridinium salting. By controlling the structure of these self-eliminating groups, activatable luminescent probes responding to different tumor markers can be constructed. These probes integrate deep NIR-II imaging, aggregation-point luminescence, large Stokes shifts, and marker-specific responses, providing a new approach for precise imaging diagnosis of tumors.

The application discloses an aggregation-induced emission compound with double fluorescence emission characteristics and a preparation method and application thereof, and the proportional fluorescence probe has a structure of general formula I. The probe molecule has a polar response group tetraphenyl ethylene as a fluorescence report unit, introduces a hydrophilic oxygen atom, connects an alpha carbon of an acetamide, and connects a polar detection sensitization group Tag chain on an amino group of the acetamide. The probe molecule improves the conjugation degree of oxygen atom lone pair electrons and a tetraphenyl ethylene pi electron system, so that the probe molecule simultaneously produces n→pi* and pi→pi* molecular transitions, and a proportional fluorescence probe which can sensitively respond to polarity change is constructed. The fluorescence probe designed in the application has the advantages that the fluorescence probe is not easily interfered by probe concentration, a detection environment and light bleaching, and experiments prove that the proportional fluorescence intensity of the fluorescence probe can sensitively respond to polarity, and the proportional fluorescence intensity and water content are linearly fitted, so that the purposes of detecting water content in an organic reagent and alcohol content in wine are achieved.

The invention discloses a novel supramolecular cyanine dye contrast agent for enhancing photoacoustic, and a preparation method and application thereof. Wherein the molecular pair cyanine dye is composed of a cationic indocyanine dye and an anionic tricyanofurancyanine dye. The dye is subjected to J-aggregation in water, so that the absorption wavelength is subjected to red shift to a near-infrared region, and excellent photothermal conversion efficiency (10-80%) and singlet oxygen quantum yield (10-50%) are shown. The photoacoustic imaging performance is excellent, and the intensity of a photoacoustic signal generated under the concentration of 25.0 mu M is 7.1 times that of ICG; the photo-thermal treatment effect is obvious, the photo-thermal conversion efficiency is as high as 66%, and the temperature is rapidly increased to 48 DEG C. In addition, the dye shows excellent light stability and photobleaching resistance, the absorbance is only attenuated by 25% under strong laser, and the dye has good biocompatibility and safety. The multi-mode application comprises photoacoustic and fluorescence imaging, photothermal and photodynamic therapy and the like, and has a good application prospect.

The application discloses an organic compound biological probe and a preparation method and application thereof, and belongs to the field of fluorescent probes. The structural formula of the organic compound biological probe is as follows, and the preparation method comprises the following steps: adding 2,4-dihydroxybenzaldehyde and anhydrous potassium carbonate into anhydrous acetonitrile or DMF, then dropwise adding 1,4-dibromobutane to obtain a colorless oily compound 1 through reflux reaction; dissolving the compound 1 and triphenylphosphine in anhydrous acetonitrile to obtain a solid compound 2 through reflux reaction; dissolving 1,1,2-trimethyl-1H-benzo[e]indole and iodoethane in anhydrous acetonitrile to obtain a compound 3 through reflux; dissolving the compound 3 and the compound 2 in anhydrous ethanol, adding piperidine, and then performing reflux reaction and purification to obtain the organic compound biological probe. The organic compound biological probe can self-assemble into nanoparticles with a size of about 1.6 nm in water, has strong anti-photobleaching ability, and integrates red light and near-infrared dual-channel imaging, pH detection, mitochondrion targeting and chemotherapy.

The application discloses an aggregation-induced emission microsphere with colorimetric-fluorescent double signals and a preparation method and application thereof. The aggregation-induced emission microsphere comprises carboxyl polystyrene microspheres and aggregation-induced emission dyes embedded in the carboxyl polystyrene microspheres; and the structural formula of the aggregation-induced emission dyes is as follows: The aggregation-induced emission microsphere has colorimetric-fluorescent double signals, is red under natural light, has strong absorption at 600 nm, and shows high light-emitting efficiency at 725 nm, effectively avoids the interference of biological autofluorescence, reduces background interference, has good light stability and light bleaching resistance, and has high molar extinction coefficient, so that the aggregation-induced emission microsphere has colorimetric and fluorescent double signal output capabilities. In addition, the preparation process of the aggregation-induced emission microsphere has high reproducibility, has the potential for large-scale synthesis, and meets the needs of industrial batch production.

The invention discloses a photobleached all-polymer optical waveguide grating sensor and a preparation method thereof, and belongs to the technical field of polymer optical waveguide grating sensors. The preparation method comprises the following steps: carrying out hot stamping on a substrate sheet to obtain a substrate sheet with a groove; spin-coating photoresist on the substrate sheet to form a photoresist core layer; photoetching the photoresist core layer through double-beam interference to obtain the photoresist core layer with interference fringes; spin-coating a thermosensitive polymer cladding material on the photoresist core layer, covering the flexible substrate and then carrying out low-temperature thermocuring so as to bond the photoresist core layer and the flexible substrate; stripping the substrate sheet, exposing the photoresist core layer, covering the protective cladding, and curing to obtain a multi-layer composite device; and performing non-uniform post-baking on the multi-layer composite device to obtain the multi-layer composite device. According to the invention, the grating period can be changed under the condition that the grating mask is not replaced, and the cost of spectrum adjustment is greatly reduced.

The invention provides a method for detecting fusion of extracellular vesicles by adopting fluorescence resonance energy transfer, and belongs to the technical field of extracellular vesicles. A dynamic fluorescence monitoring system is established, low-power laser excitation is adopted, dual-wavelength fluorescence signals are monitored at the same time, fluorescence signal data are collected, graded gain regulation and control processing is carried out through five threshold values, and a fluorescence signal super-sparse matrix is constructed; establishing a fluorescence signal processing matrix model, converting the super-sparse matrix into a dense matrix, constructing a gain matrix for signal correction, calculating a fluorescence resonance energy transfer efficiency parameter, obtaining a standardized efficiency value through matrix operation, outputting an extracellular vesicle fusion kinetic analysis result, and establishing a quantitative evaluation system. The technical problems of poor signal stability and low detection precision in the process of fluorescence resonance energy transfer detection of extracellular vesicle fusion are solved.

The invention provides a space fiber laser photobleaching device and a use method, the space fiber laser is an erbium-doped fiber laser, a gain fiber in the erbium-doped fiber laser is an erbium-doped fiber, and the gain fiber of the erbium-doped fiber laser generates fiber defects under a space irradiation condition. Therefore, the absorption coefficient of the gain optical fiber at 980nm is sharply increased, so that the gain optical fiber only absorbs signal light within a certain length and does not have an optical signal amplification effect; the erbium-doped fiber laser is connected with the irradiation bleaching laser light source, and the irradiation bleaching laser light source is used for outputting bleaching laser with the central wavelength ranging from 400 nm to 500 nm and injecting the bleaching laser into a gain fiber of the erbium-doped fiber laser so as to repair fiber defects and laser performance degradation caused by space irradiation of the erbium-doped fiber laser.

The preparation method comprises the following steps: firstly, dissolving gelatin in deionized water to form a gelatin solution, adding rhodamine B and a catalyst, and carrying out amidation reaction to chemically bond amino groups of the gelatin with carboxyl groups of the rhodamine B; then adding a cross-linking agent to cross-link the rhodamine B-gelatin conjugate into nano particles, and enabling the rhodamine B-gelatin fluorescent nano thermometer to be ellipsoidal by utilizing centrifugal force formed by high-speed stirring in the cross-linking process. The rhodamine B is firmly loaded on the gelatin nanoparticles, the loading capacity of the rhodamine B is greatly increased, the residence time of the rhodamine B in an organism is prolonged, the photobleaching effect of the rhodamine B is overcome, the rhodamine B-gelatin fluorescent nanoparticles are prepared into ellipsoids through uneven stress under the action of centrifugal force when aggregated particles are formed, and the rhodamine B-gelatin fluorescent nanoparticles are prepared into the ellipsoids. The preparation method is simple, the temperature measurement sensitivity is high, the photobleaching phenomenon of rhodamine B is effectively weakened, and the biomedical utilization prospect is good.

This invention discloses an illumination intensity modulation method for disk scanning confocal imaging, comprising the following steps: S1: Before formal imaging, a pre-imaging is performed using weak, uniform illumination; S2: The fluorescence intensity of different regions in the pre-imaging is evaluated and analyzed, and the evaluation results are obtained; S3: Based on the evaluation results, the parameter settings of the intensity modulation mechanism are adjusted to achieve different illumination in different regions of the sample; S4: The scanning points traverse the imaging area to obtain a complete image on the camera. This invention can dynamically adjust the illumination intensity of local regions in the scanning imaging as needed, and can be used to reduce photobleaching in local regions, increase the dynamic range of imaging, and enhance the signal-to-noise ratio of local regions.

The invention relates to the field of heavy metal detection, in particular to a boron-doped carbon quantum dot and a preparation method and application thereof. In order to realize synchronous detection of dichromate radicals and permanganate radicals, curcumin and m-phenylenediamine are used as a carbon source and a nitrogen source, boric acid is used as a boron element doping agent, and the boron-doped carbon quantum dots are obtained by adopting a one-step solvothermal method. Wherein curcumin and m-phenylenediamine are used as precursors, boric acid is used as a boron element doping agent, and the boron-doped carbon quantum dots are synthesized. The preparation method is simple, and the prepared B-N-CDs has blue-green fluorescence, shows excellent biocompatibility and photobleaching resistance, is successfully applied to detection of Cr2O7 < 2-> and MnO4 <-> in water, is successfully applied to the field of fluorescent ink, and has potential value in the aspect of anti-counterfeiting marks.

The application discloses a pyridine cation mitochondrial fluorescent probe, the chemical name of the probe is 4-(8-dimethylamino-5-benzocoumarin)-methylpyridine iodine salt, and the chemical structural formula is shown as formula (I). The application further discloses application of the fluorescent probe in labeling or imaging display of mitochondrial distribution or morphology in living cells and in long-range tracking display of mitochondria in living cells and imaging display of nucleoli in cells. Experiments prove that the labeled mitochondrial fluorescent probe has high light bleaching resistance and a high fluorescence quantum yield, can realize long-range tracking of mitochondria in living cells, and can label fixed nucleoli in cells. It is indicated that the fluorescent probe has potential application and development value in the fields of fluorescent probes and tissue imaging, and has a wide application prospect.

The application provides a photosensitive resin composition containing an anthracene methyl quaternary ammonium salt photosensitizer and application thereof, the photosensitizer has a quaternary ammonium group substituted methylene introduced at 10 and / or 9 positions of the anthracene ring, and an acid radical or halogen is used as a counter anion; compared with a commercially available anthracene photosensitizer, the photosensitizer has excellent fat solubility and good water solubility by introducing the quaternary ammonium salt on the premise of retaining photobleaching, brings great potential for formula design of the photosensitive composition, and can greatly reduce developing waste in a later developing process; and can be widely applied in the fields of dry films, paints, coatings, inks and molding materials and the like.

The invention discloses an organic compound biological probe and a preparation method and application thereof, wherein the organic compound biological probe is In-AIE, and the method comprises: dissolving rutin in acetonitrile, and then adding 4-formyl pyridine and n-tributylphosphine for reflux reaction to obtain compound 1; dissolving 1,1,2-trimethyl-1H-benzo[e]indole and iodoethane in anhydrous acetonitrile for reflux to obtain compound 2; adding 2,4-dihydroxybenzaldehyde and anhydrous potassium carbonate to anhydrous acetonitrile and then dropping 1,4-dibromobutane for reflux reaction to obtain colorless oily compound 3; dissolving compound 2 and compound 3 in anhydrous ethanol for reflux reaction to obtain solid compound 4; dissolving compound 1 and compound 4 in anhydrous acetonitrile for reflux reaction and then purifying to obtain solid In-AIE. It can quickly enter cells within 1 min, has strong anti-photobleaching ability, and integrates multi-channel imaging, pH detection, mitochondrial targeting and photodynamic therapy.

The invention discloses a nitrogen-doped carbon dot and a rapid fluorescence detection method thereof for indoxacarb residue, and belongs to the field of biosensor technology and food quality detection. L-theanine and ethidene diamine are used as raw materials, the nitrogen-doped carbon dots are prepared through a hydrothermal method, the N-CDs have the advantages of being stable in fluorescence emission, good in salt tolerance and excellent in photobleaching resistance, and indoxacarb can specifically quench fluorescence through the static quenching effect. By optimizing N-CDs synthesis conditions and indoxacarb detection conditions, an indoxacarb fluorescence sensing detection system with high selectivity and high sensitivity is constructed. The detection method disclosed by the invention can be suitable for detecting indoxacarb residues in environmental water samples such as tap water and river water and agricultural product matrixes such as apples and tea leaves, the standard recovery rate is good, the relative standard deviation is low, on-site rapid screening of the indoxacarb residues can be realized, and a new technical means is provided for monitoring the quality safety of the environment and agricultural products.

The anti-photobleaching excitation light-induced fluorescence heavy metal detection system comprises a system control unit, a fluorescence excitation unit, a fluorescence detection unit and a data acquisition card; the system control unit sends a pulse excitation signal to make the fluorescence excitation unit generate pulse fluorescence; the fluorescence detection unit collects the pulse fluorescence and converts it into an electric signal input into the data acquisition card; the system control unit sends a fluorescence detection signal to make the data acquisition card save n fluorescence intensity values; and the data acquisition card averages the n fluorescence intensity values. The application avoids the problem of photobleaching of the fluorescence probe caused by long-time irradiation of the excitation light by shortening the irradiation time of the excitation light, reduces the error of the detection result and improves the service life of the fluorescence probe.

Provided is a method of screening for an autophagy modulator. According to the screening method of an aspect, the autophagy modulator can be accurately screened with only a single cell. In addition, screening can be performed without using fluorescent labeling, and thus cytotoxicity and photobleaching that occur when fluorescent labeling analysis methods are used can be prevented, and the limitation of having to monitor only fluorescently labeled markers can be improved.

A fluorescence target includes a first fluorescing region and a second fluorescing region. The first fluorescing includes a first population of fluorophores that emit first fluorescence when the fluorescence target is illuminated with fluorescence excitation illumination. The first fluorescing region photobleaches at a first photobleaching rate. The second fluorescing region is proximate to the first fluorescing region and includes a second population of fluorophores that emit second fluorescence when the fluorescence target is illuminated with the fluorescence excitation illumination. The second fluorescing region photobleaches at a second photobleaching rate that is different than the first photobleaching rate.