333 results about "Fluorescence sensor" patented technology

The invention provides a colorimetric / fluorescent dual-mode sensor, a preparation method of the colorimetric / fluorescent dual-mode sensor and application of the colorimetric / fluorescent dual-mode sensor in histamine detection. The colorimetric / fluorescent dual-mode sensor comprises a horseradish peroxidase-loaded metal organic framework (HRP-AIE-MOF), hydrogen peroxide and a chromogenic substrate o-phenylenediamine (OPD), horse radish peroxidase (HRP) in the HRP-coated AIE-MOF can oxidize colorless OPD into yellow 2, 3-diaminophenazine (DAP), an ultraviolet absorption peak is generated at 425 nm, a strong fluorescence emission peak is generated at 555 nm, the HRP-coated AIE-MOF has a strong fluorescence emission peak at 450 nm, and the HRP-coated AIE-MOF and a fluorescence signal of the DAP can form a ratio fluorescence sensor. According to the invention, the excellent catalytic ability of natural enzyme and the luminescence characteristic of AIE-MOF are integrated in one system, and high-sensitivity histamine detection is realized.

The invention provides a flexible fluorescence sensor as well as a preparation method and application thereof. The flexible fluorescence sensor comprises TCTG particles and dual-network hydrogel, the TCTG particles are distributed in network pores of the dual-network hydrogel to form functional gel, the TCTG particles are formed by Ti3C2TxMXene nanosheets and graphene quantum dots, the dual-network hydrogel is formed by acrylamide and sodium carboxymethyl cellulose, and the TCTG particles are distributed in the network pores of the dual-network hydrogel to form functional gel. The functional gel is soaked in a hydrochloric acid glycol solution for treatment. The flexible fluorescence sensor provided by the invention can integrate the structural advantages of all the components, so that a synergistic coupling effect is possibly generated, a fluorescence detection function with excellent mechanical strength, frost resistance and high sensitivity is integrated into a multifunctional system, the food spoilage condition can be reliably monitored in real time under a harsh environmental condition, and the application prospect is wide. And health and economic risks caused by occupational exposure and environmental emission in an aquatic product supply chain are solved.

The invention discloses a shrimp pond water quality prediction method based on a deep echo state network, and relates to the technical field of shrimp pond water quality prediction, and the method comprises the following steps: deploying an underwater fluorescence sensor in a shrimp pond culture water body to detect a fluorescence response signal of algae, and obtaining algae concentration data in the water body in real time based on the fluorescence signal intensity; dynamic changes of algae in the prawn pond water are monitored in real time; and performing time sequence alignment on the collected algae concentration data, and constructing an algae concentration time sequence data map based on the aligned time sequence data. According to the method, fluorescence sensor data and a short-time feature extraction mechanism are fused, a deep echo state network is combined to model an algae burst trend, and early warning can be realized before red tide outbreak; and the abnormal area monitoring precision is improved by enhancing a sampling mechanism, the problem of slow recognition of emergencies by a traditional model is effectively solved, and the aquaculture water quality risk perception and intelligent management capability is remarkably improved.

The invention discloses a method for constructing a dual-mode sensor through smartphone-assisted surface molecular imprinting for detecting diphenyl phosphate and application of the dual-mode sensor, and belongs to the technical fields of biochemical analysis, functional nano materials and life science. In synthesis, solubility and selectivity of a target object and photo-initiation efficiency in a polymerization process are optimized, and diphenyl phosphate molecularly imprinted nano-enzyme MIPs is rapidly prepared through a molecular imprinting technology; in the detection, H2O2 and 3, 3, 5, 5-tetramethyl benzidine TMB are catalyzed by peroxidase-like activity of Fe and N-CDs to generate a chromogenic reaction and an inner filter effect of oxTMB is used for inhibiting a fluorescence signal, dual-signal cross validation is realized in cooperation with a smart phone, and the colorimetric-fluorescence sensor for detecting diphenyl phosphate is constructed. The sensor has specific recognition selectivity and binding affinity of diphenyl phosphate, is simple to operate and low in cost, can realize sensitive detection of diphenyl phosphate in a wide linear range, has the detection limit as low as 16 pg / mL, and is suitable for field analysis of trace DPhP in a complex water environment.

The invention discloses a method for distinguishing similar antibiotics by using a fluorescent sensing array based on YOLOv5 target recognition. The method comprises the following steps: S1, preparing GMP-Tb solid powder; s2, mixing the GMP-Tb solid powder with a rhodamine B solution in proportion to obtain a multi-proportion fluorescent probe; s3, mixing antibiotics with different concentrations with the multi-proportion fluorescent probe to obtain a fluorescent sensing array; s4, collecting color images in the fluorescent sensing array and dividing the color images into a training set and a test set; s5, constructing an OLOv5 optic nerve model, inputting the acquired color image into a YOLOv5 optic nerve model, and outputting a feature value of the acquired color image; s6, inputting the characteristic value of the color image into a classifier model for prediction classification to obtain a distinguishing result; and S7, inputting a color image formed by mixing the to-be-detected antibiotic and the multi-proportion fluorescent probe into the YOLOv5 optic nerve model to obtain a characteristic value of the color image, and then outputting a distinguishing result through the classifier model.

The present invention combines a fluorescence sensor with an array to provide a fluorescence sensing array detection platform and a detection method for multiple plasticizers. The fluorescence sensing array detection platform includes a B-doped graphene quantum dot solution using N,N-dimethylformamide as a solvent and a B-GQDs solution using cyclohexane as a solvent; the fluorescence intensity of the B-GQDs solution with DMF as the solvent at the fluorescence characteristic peak obtained under ultraviolet light excitation at a wavelength of 350 nm, and the fluorescence data at 391 nm, 413 nm, and 434 nm are used as array points 1, 2, and 3; the fluorescence intensity of the B-GQDs solution with CH as the solvent at the fluorescence characteristic peak obtained under ultraviolet light excitation at a wavelength of 350 nm, and the fluorescence data at 386 nm, 408 nm, and 430 nm are used as array points 4, 5, and 6; thus, a 3×2 fluorescence sensor array is constructed. The detection method using the fluorescence sensor array of the present invention has simple steps, and has satisfactory specificity, reproducibility, stability and practicability, and has application potential.

The invention discloses a dual-emission molecular imprinting ratiometric fluorescence sensor, a preparation method thereof and application of the dual-emission molecular imprinting ratiometric fluorescence sensor in aureomycin detection, and belongs to the technical field of chemical sensors. The preparation method of the sensor comprises the following steps: preparing silicon dioxide-quantum dot composite nanoparticles, and preparing a molecularly imprinted polymer by taking salicylamide as a template molecule; and mixing the molecularly imprinted polymer and the silicon dioxide-quantum dot composite nanoparticles in an HEPES buffer solution by adopting a post-mixing strategy to construct the dual-emission molecularly imprinted ratiometric fluorescence sensor. The double-emission molecular imprinting ratiometric fluorescence sensor has the beneficial effects that the double-emission molecular imprinting ratiometric fluorescence sensor provided by the invention is rich in fluorescence color change, rapid, high-sensitivity and visual detection of aureomycin can be realized, the whole detection process is simple, convenient and rapid, and the double-emission molecular imprinting ratiometric fluorescence sensor is suitable for being widely popularized in practical application.

The invention relates to the technical field of carbon-nitrogen ratio detection, in particular to a sweet potato carbon-nitrogen ratio detection method and system based on a multispectrum and fluorescence sensor, and the method specifically comprises the following steps: constructing a weight coefficient based on the correlation between the leaf carbon-nitrogen ratio in each growth stage and the reflectivity of each wavelength, and combining the multispectrum and fluorescence spectrum of each leaf to obtain a weight coefficient; acquiring a coupling characteristic value; correcting the coupling characteristic value according to the soil conductivity; analyzing the multi-spectral characteristics and the fluorescence spectrum characteristics of the sweet potatoes, and constructing a multi-spectral index and a fluorescence spectrum index; predicting the carbon-nitrogen ratio of the to-be-detected sweet potato leaf based on the features of the leaf, and calculating the carbon-nitrogen ratio of the to-be-detected sweet potato leaf by combining the difference between the feature vectors of the to-be-detected sweet potato leaf and the leaves in all growth stages and introducing the carbon-nitrogen ratio of the previous growth stage; certain continuity and inertia of the change of the carbon-nitrogen ratio are considered, so that the method adapts to the change of the sweet potatoes in different growth stages, and the detection precision of the carbon-nitrogen ratio is improved.

A pig for use in a pipeline is provided for determining the material of the pipeline in the context of an inline inspection. The pig includes a position determination unit and at least one braking arrangement for immobilizing the pig at a certain position in the pipeline. The pig also includes an X-ray fluorescence sensor.

The invention relates to a fluorine-containing polymer of a specific mononitroalkylbenzene aromatic hydrocarbon explosive tracer as well as a preparation method and application of the fluorine-containing polymer, and belongs to the technical field of fluorescent probes. The method specifically comprises the step of synthesizing a polymer with fluorine atoms as a solid fluorescence sensor probe. The probe realizes the detection of explosives through the interaction between fluorine atoms and nitryl and by doping CdSe / ZnS quantum dots. Based on the fluorine-containing polymer, aromatic alkyl hydrocarbon explosives (tracers) containing a single nitro group can be specifically recognized. Quantum dots are blended with the fluorine polymer, the quantum dots as a nano material are mixed and dispersed with the polymer to form a nanofiber membrane, and the fluorescence of the fluorine-containing quantum dot polymer is changed by further utilizing the interaction between fluorine and silicon atoms and nitro aromatic hydrocarbon, so that the fluorescence of the fluorine-containing quantum dot polymer is changed. Therefore, the specific detection-fluorescence rise of the mononitroalkane explosive is realized (fluorescence decline caused by interference such as light blocking is avoided).

The present invention discloses a fluorescent probe and a fluorescent label for real-time non-destructive visualization monitoring of the freshness of meat food, and their preparation methods and applications. The structural formula of the fluorescent probe HBT-Bz is simple and easy to synthesize. Using the HBT fluorophore with ESIPT properties and AIE effect as the parent body and benzoxazole ester group as the recognition group for amine compounds, a fluorescence turn-on probe is designed and synthesized. The fluorescent probe HBT-Bz responds quickly and sensitively to amine compounds, with a detection limit as low as 5.1 ppm, and can be used to fabricate a solid fluorescence sensor for detecting volatile amine compounds. The synthetic route of the fluorescent probe involved in the present invention is simple, can recognize a variety of volatile amines, has a low detection limit, and the preparation process of the fluorescent label loaded with the fluorescent probe is simple. When in use, no pretreatment of the food is required. Placing the fluorescent label in the meat food packaging can realize real-time non-destructive visualization monitoring of the food freshness, and the results are accurate and reliable.

The invention designs a preparation method of a magnetic molecular imprinting-aptamer sandwich fluorescence sensor for detecting kanamycin. And the magnetic molecular imprinting composite material Fe3O4 (at) UiO-66 (at) MIP with a specific adsorption target object KANA is prepared. When a detection target object KANA exists, the Fe3O4-coated UiO-66-coated MIP can rapidly and specifically capture the KANA in a short time. Then, a DNA single-stranded aptamer marked with FAM is added, after the aptamer and KANA captured on the surface of the Fe3O4 at-UiO-66 at-MIP are subjected to specific recognition and magnetic separation again, an aptamer probe can enter sediment along with the magnetic composite material Fe3O4 at-UiO-66 at-MIP, the fluorescence intensity of supernate is reduced, and quantitative analysis is conducted according to the fluorescence difference value delta F. When the KANA does not exist, the aptamer cannot enter the precipitate, so that the fluorescence signal intensity is not changed. Double recognition is formed through specific binding of an MIP imprinting cavity and the aptamer, matrix interference is reduced by means of fluorescence characteristics and magnetic separation capacity, the method has the advantages of being high in adsorption capacity, specific in recognition, high in sensitivity, wide in detection range, good in selectivity and the like, and rapid and accurate detection of KANA in a complex sample can be achieved.

The invention relates to the field of veterinary drug residue detection, in particular to a fluorescence sensor based on DNA molecular machine mediated split Cas12a and application of the fluorescence sensor to ofloxacin detection, the fluorescence sensor comprises a system A, a system B and a system C. According to the final concentration of each system, the system A comprises an AP / CP double-stranded compound and a 20 mM Tris-HCl buffer solution 1, the system B comprises a double-stranded compound, an sRNA probe and a 10 mM Tris-HCl buffer solution 2, and the system C comprises a DNA molecular machine mediated split Cas12a. The system C comprises a Cas12a / hRNA compound, a pDNA / psG43 signal probe, ThT and a 20 mM Tris-HCl buffer solution; aP in the AP / CP double-chain compound is an aptamer of ofloxacin, and AP and CP in the AP / CP double-chain compound are paired and connected through complementary base pairing; the sequences of AP, CP, PS, SS, sRNA, hRNA, pDNA and psG43 are respectively as shown in SEQ ID NO.1-SEQ ID NO.8. The invention also discloses a kit for detecting the content of the protein. According to the application, the nucleic acid aptamer of ofloxacin is utilized, based on a DNA molecular machine and SCas12a as a signal amplification technology and sulfo-modified G43 as a fluorescent signal probe, even if the content of ofloxacin in a sample is extremely low, detection can be accurately realized.

The invention discloses nitrogen-doped carbon quantum dots derived from American cockroach dregs as well as a preparation method and application of the nitrogen-doped carbon quantum dots, and belongs to the technical field of nitrogen-doped carbon quantum dots. The nitrogen-doped carbon quantum dots are prepared from the American cockroach dregs by a one-step hydrothermal method, optimal synthesis parameters are obtained through experimental optimization of synthesis conditions, and the prepared nitrogen-doped carbon quantum dots have excellent optical characteristics and stability; the invention also provides an application of the nitrogen-doped carbon quantum dot in Ag < + > detection, the nitrogen-doped carbon quantum dot has good selectivity, sensitivity and anti-interference performance on Ag < + >, a detection mechanism is an internal filtering effect and light-induced electron transfer, and the nitrogen-doped carbon quantum dot can be used as a preferred fluorescent material of an Ag < + > fluorescent sensor. The nitrogen-doped carbon quantum dots synthesized by the method not only have an Ag < + > sensing function, but also realize high-valued utilization of medicine residues, and also provide a new thought for self-doping of heteroatoms.

The invention provides a fluorescence sensor 4-MU (at) ZIF-8 (at) PLA-PEG as well as a preparation method and application thereof, and belongs to the technical field of visual food safety monitoring materials. The fluorescence sensor comprises a zeolite imidazate framework ZIF-8, an organic dye molecule 4-MU and a polymeric macromolecule PLA-PEG (Polylactic Acid-Polyethylene Glycol), the organic dye molecule 4-MU is coated with the zeolite imidazate framework ZIF-8 to form 4-MU (ZIF-8 nano particles with a core-shell structure, and the 4-MU (ZIF-8 nano particles with the core-shell structure are doped into a polymeric macromolecule PLA-PEG (Polylactic Acid-Polyethylene Glycol). The ZIF-8, 4-MU and PLA-PEG in the fluorescence sensor provided by the invention can cooperate with each other, can visually detect TCs with high response speed and low detection limit, and has certain mechanical properties and antibacterial properties, thereby providing a new thought for the field of intelligent packaging for detecting TCs in food at present.

The invention relates to the technical field of biomedical detection, and discloses a portable urine component detection system and method based on a fluorescence sensor array. The system comprises a fluorescence sensor array, different fluorescence probes are used for detecting different trace components in urine, and fluorescence color gradient changes are generated through a probe-target object reaction, so that bilirubin, glucose and albumin in the urine are detected. The detection system comprises a micro-fluidic chip which integrates a capillary driving channel and a colorimetric reaction area and is used for sample transmission and reaction area positioning; an ultraviolet excitation light source and a multi-angle optical sensor are arranged in the camera obscura type color acquisition module, and the camera obscura type color acquisition module eliminates ambient light interference and captures fluorescence chromaticity signals; and the intelligent data processing system is integrated with an intelligent analysis end of the smart phone, establishes a quantitative relationship between chromaticity parameters (RGB and hue saturation) and the concentration of a target object through a machine learning model, and outputs a detection result in combination with an ambient light correction algorithm.

The invention discloses a radio frequency thermal therapy equipment testing system, relates to the technical field of equipment testing, and is used for solving the problems that the uncertainty in the energy transmission process is increased, and the system output stability and response precision are reduced. The output power is calculated in combination with an analog multiplier, and difference analysis is carried out in cooperation with ideal power; meanwhile, performing fast Fourier transform on the original signal to extract a frequency concentration ratio, and calculating a heat concentration coefficient; the tissue temperature at a needle is monitored based on an optical fiber fluorescence sensor, fluorescence detection temperature and observation temperature values are calculated in combination with fluorescence lifetime, difference analysis is performed to obtain a thermal response deviation factor, and the two values are fused to obtain a feedback calibration result for equipment performance optimization, and real-time monitoring of an energy state and abnormal heat accumulation identification are realized.

The invention discloses a hemicyanine fluorescent dye-based compound as well as a preparation method and application thereof. The invention provides a compound MCYA based on hemicyanine fluorescent dye targeting AChE, the compound has high sensitivity to AChE, the detection limit can be as low as 0.0225 U / mL, and high-sensitivity detection on AChE can be realized; and the MCYA has good selectivity and strong anti-interference capability on common ions and amino acids in a biological system. A fluorescence sensor platform built by combining MCYA and AChE can realize qualitative and quantitative analysis of organophosphorus and carbamate pesticide residues, and has the advantages of high sensitivity, simplicity in operation, low cost, short detection time, suitability for rapid detection in the market and the like.

The application provides a fluorescent sensor based on a tripod [5] arene, which is obtained by self-assembly complexation of a host of a tripod [5] arene TP5 and a guest of a quaternary ammonium salt in an H2O-DMSO system. A supramolecular system is constructed by host-guest interaction between the tripod [5] arene TP5 and the amphiphilic guest TPN, and then PbS fluorescent nanoparticles are generated in situ under ion induction. Fluorescence enhancement and high-sensitivity detection (LOD=7.00*10 2+ -6 M) of Pb ‑8 are realized. In addition, the fluorescent supramolecular polymer network based on the PbS fluorescent nanoparticles can be successfully applied to in-situ detection of Pb 2+ in cells.

The invention discloses a preparation method of a portable paper-based ratiometric fluorescence sensor APBA-CsPbBr3 at-UiO-66 / Ru, which comprises the following steps: 1, adding lead bromide and cesium bromide into N, N-dimethylformamide, then adding 5-bromovaleric acid and an oleylamine ligand, and stirring; 2, perfluorooctyltriethoxysilane is added, and a precursor solution is obtained; 3, adding zirconium chloride and terephthalic acid into N, N-dimethylformamide to obtain a homogeneous solution; 4, after heating, UiO-66 is obtained; 5, stirring the precursor solution, APBA, UiO-66 and tris (2, 2-dipyridyl) ruthenium chloride hexahydrate to obtain a composite material; and 6, dropwise adding the composite material solution into the filter paper. The APBA modified material is adopted as a recognition unit, the APBA modified material and the paper base construct a fluorescence sensing platform, visual quantitative analysis of oxytetracycline in water is achieved, and the device is convenient to carry, low in detection limit, high in anti-interference performance, easy and convenient to operate and suitable for on-site rapid detection of oxytetracycline.

The invention belongs to the field of fluorescent sensors, and relates to an Ag-CP fluorescent probe material as well as a preparation method and application thereof. The structural formula of the fluorescent probe material is [Ag (HL) (L)] n, and an HL ligand is 4-(3, 5-dimethyl-1H-pyrazole-1-yl) benzoic acid. Ag-CP is prepared by the following method: dissolving HL and AgNO3 in H2O to obtain light brown turbid liquid, carrying out high-temperature reaction on the light brown turbid liquid, and cooling to obtain the Ag-CP. The Ag-CP material can identify tryptophan (Trp) molecules in an aqueous solution with high selectivity and high sensitivity, has good stability and anti-interference ability in fluorescence identification ability, and can be used as an excellent Trp molecule identification fluorescence sensor.

This invention belongs to the field of fiber optic sensing and relates to a method based on WS 2 A temperature sensor based on all-fiber fluorescence intensity comprises a single-mode fiber, a three-hole grapefruit fiber, and a multimode fiber connected in sequence; the three-hole grapefruit fiber has three air holes, in which WS is deposited. 2 The multimode fiber output end is equipped with a mounting base, on which a filter is mounted. This invention utilizes WS... 2 Assembled within a three-hole optical fiber, with single-mode and multi-mode fibers fused together at both ends, this sealed structure effectively isolates the sensor from external air, preventing contact between the outside air and the two-dimensional material on the inner wall of the fiber during heating. This slows down the decomposition of transition metal sulfides, significantly improving the fluorescent sensor's ability to detect high temperatures and extending its lifespan. The sensor itself and its detection system are coupled and output via optical fiber, eliminating the need for external spatial light or optical modulation.

The application discloses a three-channel fluorescence sensor array based on sulfur quantum dots and a preparation method and detection application thereof. The sensor array is composed of three kinds of sulfur quantum dots, namely C-SQDs, PSS-SQDs and beta-SQDs. When target objects exist, the three kinds of sensing units generate differentiated fluorescence responses, forming a unique "fingerprint map". By using principal component analysis to analyze the response mode, the array can successfully distinguish between structurally similar baicalein, fiscetin, myricetin, quercetin and rutin in a concentration range of 8.0-56 muM. In addition, the array can also perform semi-quantitative analysis on a single flavone compound in a range of 4.0-56 muM, and the first principal component has a good linear relationship with the logarithm of the concentration of the target object.

This invention discloses a method to avoid the influence of cations on carbon nanotube fluorescent sensors, and a gel-based dopamine sensor based on Al-(AT)15-SWCNTs complex and its application. The method to avoid the influence of cations on carbon nanotube fluorescent sensors first involves preparing a single-stranded DNA sequence (AT). 15 Modified single-walled carbon nanotube solution ((AT) 15 -SWCNTs); then (AT) 15 The SWCNTs solution and agarose gel were mixed at a 1:1 volume ratio and allowed to settle at (AT). 15 -SWCNTs solidify to obtain a gel-based dopamine sensor; the gel-based dopamine sensor is placed in an Al(NO₃)₃ solution for at least one hour, and then washed by immersing it in an HCl solution with pH ≤ 3.7 to remove residual free Al from the gel. 3+ The ions ultimately yield Al−(AT). 15 A gel-based dopamine sensor for ssDNA-SWCNT complexes. Trivalent aluminum ions pre-occupy the interaction sites of phosphate groups to prevent further interactions between other cations and phosphate groups. Agarose gel-based ssDNA-SWCNTs avoid cation-induced aggregation.

本发明公开了一种基于静电驱动的双酶级联放大荧光传感器及其制备方法和应用，所述纳米酶荧光传感器由探针Azo‑Bodipy 685、胆碱氧化酶（CHO）和氯化乙酰胆碱（ACh）组成。本发明基于静电吸附原理，提出静电络合共固定化‑酶级联反应协同策略，构建一种新的静电驱动荧光传感器，利用ACh的季铵盐正电荷与CHO表面负电荷的静电作用，在特异性荧光探针Azo‑Bodipy 685表面构建纳米尺度空间限域的酶反应微环境。当有机磷农药抑制乙酰胆碱酯酶（AChE）时，氯化胆碱生成减少导致CHO催化产生的过氧化氢量下降，荧光信号强度减弱，一系列荧光强度的变化可以实现检测AChE活性和测定有机磷农药残留含量。

The present invention relates to a preparation method and application of a cyclodextrin - histidine / lanthanum complex, belonging to the technical field of fluorescence sensors. The preparation method includes: mixing a cyclodextrin - histidine fluorescent molecule with a lanthanum source in a solution and heating for reaction to obtain a cyclodextrin - histidine / lanthanum fluorescent complex; wherein, the preparation method of the cyclodextrin - histidine fluorescent molecule includes: mixing an aldehyde - group cyclodextrin and histidine in an aqueous solution for reaction to obtain; the aldehyde - group cyclodextrin is an aldehyde - group cyclodextrin obtained by pre - oxidizing β - cyclodextrin with sodium periodate. Compared with the prior art, the cyclodextrin - histidine / lanthanum complex prepared by the present invention can directly and highly specifically recognize phosphate ions, realizing highly sensitive detection of phosphate ions, being more suitable for accurate detection of trace pollutants at low concentrations and highly selective detection. In addition, portable detection of phosphate ions can be realized through a visualization technique based on fluorescence images.

The application discloses a method for imaging magnesium ions in living cells based on chemically modified deoxyribozyme, and belongs to the technical field of metal ion imaging. The method comprises the following steps: chemically modifying deoxyribozyme 10-23, screening and obtaining deoxyribozyme 10-23 (CaBn) which is modified with carboxyl (Ca) at the 8th position of the catalytic ring and benzene ring (Bn) at the 12th position; performing biochemical characterization and comparison; constructing a fluorescence sensor responding to magnesium ions; characterizing the performance; and applying the fluorescence sensor to imaging magnesium ions in living cells. Compared with the wild type, the application can catalyze the cleavage reaction under the condition of lower concentration of magnesium ions; therefore, the fluorescence sensor constructed from the deoxyribozyme can more effectively respond to lower concentration of magnesium ions in vitro, and the detection limit reaches 0.03 mM; in addition, the fluorescence sensor can perform fluorescence imaging on endogenous magnesium ions in living cells, and provides a new molecular tool for the field of molecular biology.

The application provides a preparation method and application of a near-infrared two-region fluorescent sensor, and chiral single-walled carbon nanotubes are separated by using a double water phase extraction method; materials in the separation process include deionized water, polyethylene glycol, dextran, sodium dodecyl sulfate, sodium deoxycholate and cholic acid sodium hydrate; the chiral single-walled carbon nanotubes are dispersed and mixed with 4-nitrobenzene tetrafluoroboric acid diazonium salt to obtain the fluorescent sensor; high-purity (6,5)-SWCNT is efficiently and simply separated by using the double water phase extraction technology, the prepared SWCNT-NBD nanomaterial has good optical performance, including bright light emission in the near-infrared two-region, has good penetration capacity on biological tissues, the fluorescent detector (SWCNT-NBD) has low detection line, wide linear range, good selectivity on DA, and is convenient to prepare and low in cost.

This invention relates to the field of medical detection technology and discloses a fluorescent sensor for high-sensitivity detection of circRNA and its detection method based on machine learning. The sensor includes a splitting probe M, a splitting probe N, a circular template T, a probe CrRNA, and a reporter gene. The 5' end of probe M is modified with a phosphate group, and the 5' end of probe M and the 3' end of probe N each have 15 nucleotides complementary to the target. The single-stranded DNA of splitting probe M and the single-stranded DNA of splitting probe N are ligated into the single-stranded DNA of probe MN in the presence of the target. The 5' end of the circular template T is modified with a phosphate group, and probe T, from its 5' end to its 3' end, consists of the N probe complementary region, the functional region, and the M probe complementary region, respectively. The CrRNA probe, from its 5' end to its 3' end, consists of the protein-binding region and the functional complementary region, respectively. The 5' end of the reporter gene is modified with a fluorescent group, and the 3' end is modified with a quenching group, which quenches the fluorescence signal of the 5' end fluorescent group.

The invention relates to a preparation method of a fluorescence sensor. The invention relates to a preparation method of a portable pesticide detection fluorescence sensor of silver nanocluster (AgNCs) at zeolite imidazolate skeleton (ZIF) at polydopamine (PDA) and application of the portable pesticide detection fluorescence sensor in on-site rapid detection of 2, 4-dichlorophenoxyacetic acid (2, 4-D), and belongs to the technical field of fluorescence sensors. The method comprises the following steps: wrapping AgNCs with ZIF, and modifying the surface of the AgNCs with dopamine to form an AgNCs-ZIF-PDA composite material with high stability, high fluorescence enhancement, high enzyme responsiveness and high controllability; then, the material is integrated into a nano clay-acrylamide hydrogel matrix with high fitness, and a sensor with an adjustable shape is constructed. The sensor can be adaptively attached to the surface of a plant and is used for long-term in-situ monitoring of 2, 4-D pesticide. And in combination with an image processing algorithm, the system realizes accurate tracking of the tomato plant surface 2, 4-D degradation process, and the detection limit reaches 23.3 ng / mL. According to the invention, non-intrusive and low-cost technical support is provided for crop health management and sustainable precision agriculture.