131 results about "Fluorescence sensor" patented technology

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 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.

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 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.

This invention discloses a dual-emission molecularly imprinted ratiometric fluorescence sensor, its preparation method, and its application in the detection of chlortetracycline, belonging to the field of chemical sensor technology. The preparation method of this sensor includes the following steps: preparing silica-quantum dot composite nanoparticles; preparing a molecularly imprinted polymer using salicylamide as a template molecule; and using a post-mixing strategy to mix the molecularly imprinted polymer and silica-quantum dot composite nanoparticles in HEPES buffer to construct the dual-emission molecularly imprinted ratiometric fluorescence sensor. The advantages of this invention are: the dual-emission molecularly imprinted ratiometric fluorescence sensor provided by this invention exhibits rich fluorescence color changes, enabling rapid, highly sensitive, and visual detection of chlortetracycline; and the entire detection process is simple, convenient, and fast, making it suitable for widespread application in practical applications.

The application belongs to the field of coordination chemistry and analytical sensing technology, and particularly relates to a Zn(II)-Tb(III) complex ratio fluorescence sensor and a preparation method and application thereof. The sensor is a double-metal coordination polymer formed by coordination of Zn(II) ions, Tb(III) ions, nitrogen-containing organic ligands and carboxylic acid organic ligands. Under excitation conditions, the sensor simultaneously generates an emission signal of ligand coordination with Zn(II) and a characteristic emission signal of Tb(III) ions, forming intrinsic double emission. By monitoring the fluorescence intensity ratio (I395 / I549) of the two characteristic emission peaks at 395 nm and 549 nm, ratio fluorescence detection of propyl gallate can be realized, and the detection limit is as low as 0.35 μM. The sensor of the application has a simple synthesis method, a rapid detection process, and realizes internal calibration by using a ratio signal, has strong anti-interference ability, and is suitable for detection of propyl gallate in edible oil and other actual samples.

The present application relates to the technical field of organic synthesis, and particularly relates to a zinc-based fluorescent probe containing a pyridyl carboxylic acid type component, and a preparation method and application thereof. 22 H 14 N3O2)(CHO2)(H2O)·C3H7NO·3H2O; the zinc-based fluorescent probe containing the pyridyl carboxylic acid type component belongs to a monoclinic system, and a space group is P 2 1 / c ; cell parameters are a = 7.2925(2) Å, b = 26.6839(8) Å, c = 12.8618(4) Å, α = 90°, β = 105.5770(10)°, gamma = 90°. The zinc-based fluorescent probe has good thermal stability and large light emission intensity, the preparation method is simple, and the zinc-based fluorescent probe can be used as a fluorescent sensor to detect Fe 3+ and 2,4,6-trinitrophenol in a DMF solution with high sensitivity and high selectivity.

This invention discloses a method and application for constructing a dual-mode sensor for detecting diphenyl phosphate using smartphone-assisted surface molecular imprinting, belonging to the fields of biochemical analysis, functional nanomaterials, and life science technology. In the synthesis process, the solubility, selectivity, and photoinitiation efficiency of the target analyte during polymerization are optimized, and molecularly imprinted nanozymes (MIPs) for diphenyl phosphate are rapidly prepared using molecular imprinting technology. In the detection process, the peroxidase-like activity of Fe,N-CDs catalyzes the colorimetric reaction between H₂O₂ and 3,3,5,5-tetramethylbenzidine (TMB), and the internal filtering effect of oxTMB suppresses the fluorescence signal. Combined with a smartphone, dual-signal cross-validation is achieved, constructing a colorimetric-fluorescence sensor for detecting diphenyl phosphate. This sensor exhibits specific recognition selectivity and binding affinity for diphenyl phosphate, is simple to operate, and low in cost. It can achieve sensitive detection of diphenyl phosphate over a wide linear range, with a detection limit as low as 16 pg / mL, making it suitable for on-site analysis of trace DPH in complex aquatic environments.

The invention relates to a diagnostic method for determining the oil quality of an engine oil for an internal combustion engine (2) of a vehicle, wherein the engine oil is or is made with a fluorescent dye, and wherein the internal combustion engine (2) is located in an engine oil circuit (1) in which a detector (6), in particular an LED-based fluorescence sensor, is arranged for detecting a fluorescence intensity, comprising the steps: - if an engine oil change has been detected, an oil quality test routine is started in which the fluorescence intensity is recorded with the detector (6) and stored as the initial intensity value, - repeated, in particular continuous or regular, measurement of the fluorescence intensity of the engine oil as the current intensity value, and - if a determined current intensity value is less than or equal to approximately 10 percent of the initial intensity value, a message is issued indicating that an engine oil change is required.

The application provides a preparation method of a ratio fluorescent aptamer sensor for detecting streptomycin in milk, and belongs to the field of food safety detection. The application comprises screening of streptomycin (STR) specific aptamer and construction of a ratio fluorescent sensor. The STR aptamer (Apt) is obtained by using a magnetic graphene oxide screening technology for the first time, the binding site is analyzed according to the secondary structure and molecular docking analysis, and the Apt52 with the best affinity to the target is obtained by truncation. The carbon quantum dots (CQDs) modified by the Apt52 are used as a reference signal, the AgNCs-SMP@ZIF-8 is used as a response signal to construct a fluorescent sensing method for judging whether the streptomycin is contained in the sample to be detected. The specific binding of the aptamer to the target causes the AgNCs-SMP@ZIF-8 to expose and quickly adsorb a large amount of Cu 2+ The fluorescence signal of the AgNCs-SMP@ZIF-8 is quenched, and the fluorescence signal of the CQDs always remains stable, and the streptomycin residue is detected by the fluorescence signal ratio change of the AgNCs-SMP@ZIF-8 and the CQDs. The detection limit of the sensor for the STR is 0.978 nM, and the sensor has satisfactory specificity and sensitivity.

The application belongs to the technical field of chemical analysis and detection, and discloses a zinc oxide quantum dot fluorescent sensor and application of the zinc oxide quantum dot fluorescent sensor in detection of kaempferol. The zinc oxide quantum dot fluorescent sensor is prepared by stirring zinc salt solution and lye uniformly, then adding amino silane and water to carry out sol-gel reaction to prepare a ZnO-QDs fluorescent probe solution; then, a substrate is immersed in the ZnO-QDs fluorescent probe solution to carry out incubation, and drying is carried out to obtain the zinc oxide quantum dot fluorescent sensor. S The zinc oxide quantum dot fluorescent sensor is applied to detection of kaempferol, can produce specific response with kaempferol, makes the fluorescence intensity of the ZnO-QD fluorescent probe gradually increase with the increase of the concentration of kaempferol, and can effectively exclude the interference of structural analogs such as quercetin and luteolin, so that the kaempferol in the sample can be accurately quantified; and the detection cost is low, the operation is convenient, the detection efficiency is high, the detection is green and safe, and the zinc oxide quantum dot fluorescent sensor is suitable for popularization and application.

A method for rapidly detecting and identifying food-borne pathogens by using a two-dimensional / zero-dimensional MXene / GQDs Schottky heterojunction fluorescence sensor array based on machine learning comprises the following steps: synthesizing three nitrogen-doped graphene quantum dots through a hydrothermal method, determining the optimal excitation wavelength, concentration, reaction temperature and pH value of the nitrogen-doped graphene quantum dots, and further determining the fluorescence intensity of the nitrogen-doped graphene quantum dots under the optimal condition; constructing a fluorescence sensor array, mixing the three graphene quantum dots with target heavy metal ions, incubating, then measuring fluorescence intensity to obtain fluorescence response data, and normalizing the data to obtain the fluorescence response data. And analyzing by using machine learning methods of a decision tree, a support vector machine, K nearest neighbor, linear discriminant analysis, naive Bayes and a neural network. The prepared fluorescence sensor array can rapidly identify heavy metal ions, is excellent in accuracy, sensitivity and stability, provides an economical and efficient solution for heavy metal ion detection, and has remarkable application potential in environmental monitoring.

This invention relates to a method for simultaneously detecting *Salmonella typhimurium* and *Staphylococcus aureus* in chicken meat based on an instantaneous steady-state upconversion fluorescence sensor. First, a water-soluble upconversion material is encapsulated in a hollow cylinder to prepare an upconversion fluorescence cuvette. Next, a fluorescence sensor is constructed, comprising magnetic graphene oxide, aptamers specifically recognizing *Salmonella typhimurium* and *Staphylococcus aureus*, and enzyme modifications. By measuring the fluorescence signals, a detection standard curve for the two target bacteria is established. This method can determine the content of *Salmonella typhimurium* and *Staphylococcus aureus* in chicken meat. This invention improves the reusability of materials and the accuracy of detection results through the prepared upconversion fluorescence cuvette, simplifies the operation process and reduces costs by utilizing magnetic graphene oxide, and enhances the sensitivity of the sensor by utilizing enzyme catalysis. This detection method has a wide linear detection range and a low detection limit, showing promising application prospects.

This invention discloses an Eu-Mn-HOF material, its preparation method, and its application in the detection of flavin in Burkholderia gladioli. This invention utilizes Eu... 3+ Excitation is loaded onto a HOF support to form a red probe. Utilizing the fluorescence internal filtering effect, it becomes a turn-off fluorescent sensor, namely the Eu-Mn-HOF material. This Eu-Mn-HOF material cleverly utilizes Eu... 3+ The signal amplification function of the fluorescence internal filtration effect enables the detection method established using this Eu-Mn-HOF material to achieve an extremely low detection limit (0.839 μM), effectively meeting the needs for accurate detection and early warning of trace toxoflavones. The incubation reaction between the Eu-Mn-HOF material and toxoflavones, as well as the subsequent fluorescence detection process, only requires 15 minutes, and the entire detection cycle can be controlled within 45 minutes. This represents an efficiency improvement of more than 8 times compared to traditional detection methods, greatly satisfying the practical needs of rapid on-site food safety testing.

The invention discloses an AIE fluorescent sensor. The AIE fluorescent sensor is identified by a compound of a quinolinic acid derivative functionalized by a host molecule 2-hydroxy-1-naphthaldehyde and Eu < 3 + > in a DMF-H2O solution. The sensor shows yellow fluorescence in a solvent DMF-60% H2O, aqueous solutions of Fe < 3 + >, Cu < 2 + >, Sr < 2 + >, Al < 3 + >, Ag < + >, Ca < 2 + >, Hg < 2 + >, Fe < 2 + >, Co < 2 + >, Ni < 2 + >, Cd < 2 + >, Pb < 2 + >, Zn < 2 + >, Cr < 3 + >, Mg < 2 + > and Ba < 2 + > are respectively added into the solution, and only the addition of Cu < 2 + > can quench the fluorescence of the sensor. In addition, an aqueous solution of ATP, ADP, AMP, H2PO4 <->, HPO4 < 2-> and Cl <-> is added into the sensor containing the copper ions and the europium ions, and only the ATP is added, so that fluorescence of the sensor can be turned on. The recognition performance of Cu < 2 + > fluorescence quenching and ATP fluorescence opening can be used for circularly recognizing Cu < 2 + > and ATP for more than four times. Therefore, the AIE sensor can be used for fluorescent cycle recognition of copper ions and ATP (adenosine triphosphate). Meanwhile, the test paper prepared by the fluorescence sensor can also be used for detecting Cu < 2 + > and ATP. The fluorescence recognition performance has important application value in the field of ion and molecular recognition.

The invention discloses a fluorescent sensing material for detecting Cu < 2 + >, Ag < + > and Au < 3 + > ions as well as a preparation method and application of the fluorescent sensing material. Specifically, the crystal belongs to a monoclinic system, the space group is P21 / n, the molecular formula is C122H96N4O16Zn4, the molecular weight is 2135.50, the cell parameters a are equal to 13.8299 (7), the cell parameters b are equal to 22.8747 (12), the cell parameters c are equal to 31.8830 (16), the cell parameters alpha are equal to 90 degrees, the cell parameters beta are equal to 95.746 (2) degrees, and the cell parameters gamma are equal to 90 degrees. The prepared fluorescence sensing material has a clear space structure and an accurate molecular formula, can efficiently and rapidly detect Ag < + >, Cu < 2 + > and Au < 3 + > ions, and has a wide application prospect as a fluorescence sensor. The technology has the advantages of simplicity in operation, low cost, stable performance and the like.

This invention provides a sensor and its preparation method for detecting aflatoxin B1, belonging to the fields of analytical chemistry and food safety detection technology. The sensor includes a fluorescence quenching unit and a molecular recognition and signaling unit. The fluorescence quenching unit is an amino-functionalized zirconium-based metal-organic framework material UiO-66-NH2. The molecular recognition and signaling unit is a specific nucleic acid aptamer for aflatoxin B1, one end of which is covalently modified with a fluorescent dye. The nucleic acid aptamer binds to the surface of UiO-66-NH2 through adsorption. In the absence of aflatoxin B1, the fluorescence is quenched; in the presence of aflatoxin B1, the nucleic acid aptamer binds to the target analyte and dissociates from the UiO-66-NH2 surface, restoring fluorescence. This invention constructs a fluorescence "turn-on" sensor based on the UiO-66-NH2 / TAMRA aptamer, possessing both high sensitivity and specificity. Through visualization hydrogel technology, it achieves low-cost, rapid, and on-site detection of aflatoxin B1 in complex matrices.

The application discloses a cadmium-based metal-organic framework material and a preparation method and application thereof. 60 H 34 Cd2N 12 O8S, and the preparation method comprises the following steps: uniformly mixing cadmium nitrate tetrahydrate, 2,6-bis(benzimidazole-1-yl)pyridine, 5,5 ' -benzothiadiazole-4,7-diisophthalic acid, N,N'-dimethylformamide, methanol, ultrapure water and nitric acid according to a predetermined proportion; the mixture is warmed to 115-125 DEG C and reacted for 70-75 hours to obtain yellow flaky crystals; the collected crystals are washed with ethanol and dried in air. The cadmium-based metal-organic framework material can be applied to the preparation of a fluorescent probe or a fluorescent sensor for detecting anthrax biomarker DPA, realizes selective recognition of anthrax biomarker DPA through fluorescence blue shift, and the detection limit is 1.5 mu M.

This invention relates to a three-emission ratio fluorescence nanosensor for detecting tetracycline and its preparation method. The sensor uses a carbon dot-gold cluster nanocomposite material as the fluorescence signal. The synthesis steps and detection process of the carbon dot-gold cluster nanocomposite material in this invention are simple, convenient, and rapid, exhibiting rich fluorescence color changes. It does not require the assistance of complexes or coupling reagents. By constructing a three-emission ratio fluorescence sensor, the goal of highly sensitive and selective detection of tetracycline can be achieved.

The invention discloses a preparation method and application of an aromatic dicarboxylic acid-terbium complex fluorescent sensor array. The fluorescent sensor array comprises three fluorescent probes, the terbium complexes are respectively a 5-methoxy isophthalic acid-terbium complex, a 5-hexadecyloxy isophthalic acid-terbium complex and a 5-(6 '-cholesterol) hexyloxy isophthalic acid-terbium complex, and the preparation method comprises the following steps: (1) dissolving an aromatic dicarboxylic acid ligand in DMSO (dimethylsulfoxide) to obtain an aromatic dicarboxylic acid ligand mother solution; dissolving a terbium source in distilled water to obtain terbium ion mother liquor; and (2) adding the terbium ion mother liquor into an HEPES buffer solution, adding an aromatic dicarboxylic acid ligand mother liquor into the HEPES buffer solution, and carrying out constant-temperature reaction at 30-40 DEG C for 40-95 minutes to obtain the aromatic dicarboxylic acid-terbium complex. The fluorescent sensor array can be used for detecting tetracycline, cefixime, chloramphenicol and ciprofloxacin, and is high in accuracy and sensitive.

This invention discloses the application of a thiazo[a]thiazolium fluorescent derivative in the sensing and detection of butyl nitrite. This fluorescent derivative uses the electron-deficient thiazo[a]thiazolium group as the core, with symmetrically connected at both ends a benzene ring with a typical "propeller" conformation and methoxylated triphenylamine at the para- or ortho-position as electron donors, forming a D-A-D type structure. This derivative exhibits high fluorescence quantum yield, excellent intramolecular charge transfer (ICT) characteristics, and good photophysical properties, demonstrating excellent sensing performance for butyl nitrite, including high sensitivity, fast response speed, and short recovery time. Furthermore, this fluorescent derivative is prepared into a fluorescent sensing film with good photochemical stability using a drop-coating method, and then assembled into a device to construct a thin-film fluorescent sensor, demonstrating significant application potential and practical value in the high-sensitivity detection of butyl nitrite.