79 results about "Tetramethyl benzidine" patented technology

The invention discloses a fluorescent colorimetric sensor for detecting circulating tumor cells and a preparation method of the fluorescent colorimetric sensor. The preparation method comprises the following steps: S4, adding a prepared detection antibody modified with horse radish peroxidase and used for detecting the circulating tumor cells, and incubating; s5, adding a Tris buffer solution and a H2O2 solution, and incubating; s6, preparing an EuMOF nanoflower solution; and S7, adding the EuMOF nanoflower solution and 3, 3 ', 5, 5'-tetramethyl benzidine to react, detecting the fluorescence intensity in the presence of circulating tumor cells with different concentrations by using a luminoscope, detecting the ultraviolet absorbance value in the presence of circulating tumor cells with different concentrations by using a multifunctional microplate reader, and constructing a fluorescence intensity-concentration working curve and an ultraviolet absorbance value-concentration working curve. The method is used for qualitative and quantitative analysis and detection of the circulating tumor cells, realizes bimodal signal response to the circulating tumor cells, and has high sensitivity and simplicity and convenience in operation.

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 belongs to the technical field of sensors, and relates to an array sensor based on cerium-based metal organic framework nano-enzyme and detection application of perfluoroalkyl compounds. The array sensor is a Ce-MOF triple enzyme activity array sensor and is provided with a plurality of mutually independent sensing channels; the sensing channel contains a Ce-MOF nano enzyme and a chromogenic substrate; the chromogenic substrates comprise a first chromogenic substrate, a second chromogenic substrate and a third chromogenic substrate, the first chromogenic substrate comprises 3, 3 ', 5, 5'-tetramethyl benzidine, the second chromogenic substrate comprises 2, 4-diaminophenol and 4-aminoantipyrine, and the third chromogenic substrate comprises xanthine, purine oxidase and nitrogen blue tetrazole. The MOF nano-enzyme array sensor constructed by the invention has relatively high sensitivity and selectivity in identification and distinguishing of PFASs compounds, not only can accurately distinguish single PFASs compounds, but also can perform quantitative detection, and has good response to PFASs with different concentrations.

The invention discloses a method for detecting glucose on the basis of cascade catalysis of cerium dioxide / gold nano cluster-Prussian blue nano enzyme (AuNCs-CeO-HMPB). The material is prepared by compounding cerium dioxide (CeO) with similar glucose oxidase activity and hollow Prussian blue nanoparticles (AuNCs-HMPB) modified by gold nanoclusters with similar peroxidase activity through a hydrothermal assembly method. In the presence of glucose, CeO catalyzes oxidation of glucose to generate gluconic acid and H2O2, then AuNCs-HMPB synergistically catalyzes decomposition of newly generated H2O2 to generate high active oxygen species, further a colorless 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) color developing agent is oxidized to generate obvious color change, and based on the cascade catalytic reaction, the enzyme-free glucose colorimetric sensor is successfully constructed. The sensor shows excellent detection performance on glucose under optimized conditions (pH = 4.0, 50 DEG C), the linear detection range is 10.00-90.00 [mu] mol / L, and the detection limit is 2.1 [mu] mol / L (S / N = 3).

The invention relates to a diatomic catalyst for detecting carbosulfan pesticide residue and a preparation method, and belongs to the technical field of food safety detection. According to the invention, a reducing sulfide generated by breaking a nitrogen-sulfur (N-S) bond of carbosulfan under an acidic condition is used as a specific substance. The reductive sulfide not only can prevent bimetal active sites in the diatomic catalyst, but also consumes hydroxyl radicals generated by catalyzing hydrogen peroxide (H2O2), and the sensing switch enzyme formed by a dual enzyme inhibition mechanism causes the enzyme substrate 3, 4-dihydroxyl-3, 4-dione to be converted into the diatomic catalyst, so that the catalytic activity of the diatomic catalyst is improved. The blue color of the 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) gradually becomes light along with the increase of the concentration of carbosulfan, sensitive visual detection is implemented, and after a blue product is read by using an ultraviolet spectrophotometer, the absorbance value generated by an ultraviolet absorption spectrum at 654 nm is linearly dependent on carbosulfan. The prepared diatomic catalyst effectively improves the detection sensitivity of the carbosulfan pesticide residue, and has good popularization and application prospects.

The invention discloses a method for detecting aflatoxin B1 in coffee based on colorimetric and photo-thermal dual modes of MXene (at) Pt nano-enzyme, which comprises the following steps: etching Ti3AlC2 by using LiF and HCl to obtain MXene, synthesizing platinum nano-particle modified MXene nano-enzyme (MXene (at) Pt) by using dopamine carbon dots and sodium borohydride as reducing agents and adopting an in-situ reduction technology, and detecting aflatoxin B1 in coffee by using the MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt). The MXene (at) Pt shows near-infrared light stimulation enhanced peroxidase-like activity and photo-thermal performance and can catalyze blue deepening and temperature rising of a substrate 3, 3 ', 5, 5'-tetramethyl benzidine (TMB), when aflatoxin B1 exists, POD-like activity of MXene (at) Pt nano-enzyme is inhibited, and colorimetric and temperature signals are reduced; a method for detecting the AFB1 by the colorimetric temperature dual-mode sensor is established, and the method has the characteristics of high sensitivity, strong specificity, simplicity and rapidness in operation and the like.

The application discloses a machine learning enhanced silver-based covalent organic framework nanoscale enzyme colorimetric detection method and application thereof, and constructs a covalent organic framework loaded with silver nanoparticles to form a nanoscale enzyme with oxidase-like activity, which is used for rapid visual detection of mercury ions. When mercury ions exist, silver ions in the COF-AgNPs can form silver amalgam with the mercury ions, thereby catalyzing the colorless substrate 3,3',5,5'-tetramethylbenzidine to generate a blue oxidation product oxTMB. The content of mercury can be judged by detecting the absorbance and RGB value changes of the color development reaction. Meanwhile, a machine learning data analysis strategy of a support vector machine model is adopted to perform five-fold stratified cross-validation analysis on the obtained absorbance and RGB values, so that the detection range is expanded and the detection sensitivity is improved.

The invention discloses a nano-enzyme-SERS (Surface Enhanced Raman Scattering) bifunctional sensor for detecting colorectal cancer markers with high sensitivity as well as a preparation method and application of the nano-enzyme-SERS bifunctional sensor. The preparation method comprises the following steps: coating a layer of platinum (Pt) on the surface of gold nanoparticles (AuNPs) by utilizing a chemical reduction method so as to form gold-platinum nanoparticles (Au (at) Pt NPs); assembling the synthesized Au (at) Pt NPs into an aminated capillary tube through electrostatic adsorption, so as to prepare a capillary tube SERS (Surface Enhanced Raman Scattering) substrate; the surface of Au (at) Pt NPs is modified with a marker aptamer through an Au-S bond, and the nano enzyme-SERS dual-function sensor is prepared. In the presence of hydrogen peroxide (H2O2), the Au (at) Pt NPs can catalyze the oxidation of 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) to generate oxidized TMB (oxTMB) with a strong SERS (Surface Enhanced Raman Scattering) signal. When Hcy exists, the reductive sulfydryl of Hcy consumes hydroxyl free radicals (. OH) generated by H2O2 decomposition, so that TMB oxidation is inhibited, and SERS signal intensity is weakened. A linear regression equation of the logarithm of the Hcy concentration and the signal intensity is drawn according to the SERS signal intensity, so that quantitative detection of the Hcy is realized.

The invention provides an ascorbic acid high-sensitivity colorimetric sensor as well as a preparation method and application thereof, and aims to solve the problem of low sensitivity of an MOFs (Metal-Organic Frameworks) nano material in ascorbic acid detection. Ce-UiO-66-NH2 nano enzyme particles can catalyze O2 to oxidize TMB (Tetramethylbenzidine) to generate a blue product (TMBOX) under an acidic condition; based on the principle that the absorbance of a mixed solution is reduced due to the fact that the ascorbic acid can react with TMBOX, the high-sensitivity ascorbic acid colorimetric sensor composed of Ce-UiO-66-NH2 nano-enzyme particles with the diameter of 10-50 nm and a chromogenic substrate 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) is constructed. Compared with MnO2, Pt-BGP NCs, CeO2 (at) PTA HNS and Co-PB NCs, the prepared ascorbic acid high-sensitivity colorimetric sensor has the advantages that the reaction time is shorter, and the content of ascorbic acid can be rapidly measured within 15 seconds. Based on the principle, the invention further provides a portable colorimetric test paper for visually detecting the ascorbic acid, and the ascorbic acid in the liquid lemon water can be semi-quantitatively detected by naked eyes within 30 seconds.

The invention discloses a machine learning enhanced silver-based covalent organic framework nano-enzyme colorimetric detection method and application thereof, and constructs a nano-enzyme which is formed by loading silver nanoparticles on a covalent organic framework and has oxide-like enzyme activity, and the nano-enzyme is used for rapid visual detection of mercury ions. When mercury ions exist, silver ions in the COF-AgNPs can form silver amalgam with the mercury ions, so that a colorless substrate 3, 3 ', 5, 5'-tetramethyl benzidine is catalyzed to generate a blue oxidation product oxTMB. And the mercury content can be judged by detecting the absorbance and RGB value change of the chromogenic reaction. And meanwhile, a machine learning data analysis strategy of a support vector machine model is adopted to carry out five-fold layered cross validation analysis on the obtained absorbance value and RGB value, so that the detection range is expanded, and the detection sensitivity is improved.

The invention belongs to the technical field of tin ion detection, and provides a method for detecting tin ions based on Ce-UiO-66-NO2 nano enzyme. The method comprises the following steps: mixing Ce-UiO-66-NO2 nano-enzyme with colorless 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) to generate blue oxidation-state TMB, then adding a sample containing tin ions (Sn < 2 + >), and reducing the oxidation-state TMB by utilizing the strong reducibility of the tin ions (Sn < 2 + >), so that the color of the solution becomes light; the tin ions (Sn < 2 + >) are qualitatively detected according to color change, or the tin ions (Sn < 2 + >) are quantitatively detected by utilizing a linear relation between the change of the absorbance value of the solution before and after the tin ions (Sn < 2 + >) are added and the concentration of the tin ions (Sn < 2 + >). The method has the advantages of low detection limit, high selectivity and good stability, and realizes the purpose of rapid detection of tin ions in tap water.

The invention relates to the technical field of analytical chemistry and food pharmacy detection, in particular to a rutin antioxidant activity colorimetric determination method based on a composite nano enzyme, which comprises the following steps: mixing a to-be-detected sample solution with an ABTS free radical cation working solution to carry out first reaction, so that an antioxidant substance in a sample and ABTS free radical cations are subjected to scavenging reaction; adding the composite nano enzyme, a 3, 3 ', 5, 5'-tetramethyl benzidine solution and a hydrogen peroxide solution into a system after the first reaction is completed, and initiating a second reaction; and measuring the absorbance value of the system after the second reaction under a specific wavelength, comparing the absorbance value with the standard curve obtained through the treatment in the same step, and calculating the antioxidant activity expressed by the equivalent concentration of rutin in the sample to be detected. By optimizing reaction conditions, the method provided by the invention simplifies operation steps and can provide accurate measurement results in a wider concentration range.

The invention provides a high-entropy nano enzyme. The chemical formula of the high-entropy nano enzyme is Mn < 0.4 > Co < 0.4 > Ni < 0.4 > Cu < 0.4 > Zn < 0.4 > Fe < 2.0 >) O. The invention also provides a preparation method of the high-entropy nano-enzyme, which comprises the following steps: dissolving manganese nitrate tetrahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, copper nitrate trihydrate, zinc nitrate hexahydrate and sodium citrate in deionized water to prepare a clear solution A; dissolving potassium ferricyanide in deionized water to prepare a clear solution B; directly pouring the solution B into the solution A, stirring, standing and aging the obtained mixed solution at room temperature, and centrifugally collecting a product; and calcining the sample powder in a muffle furnace to obtain the high-entropy nano-enzyme. The invention further provides a catalyst which is composed of the high-entropy nano enzyme, 3, 3 ', 5, 5'-tetramethyl benzidine and H2O2. The invention also provides a method for detecting reduced glutathione by using the microfluidic paper chip analysis device. The invention provides a new normal form for constructing a multifunctional biosensing and environment monitoring platform.

The application discloses a preparation method of carbon dot nanometer enzyme, which comprises the following steps: dissolving oxalic acid, polyacetyl imine and ferric nitrate in ultrapure water, heating and mixing, cooling to room temperature, centrifuging, filtering, dialyzing and taking supernatant to obtain the carbon dot nanometer enzyme; and a double-mode detection method for colorimetric and fluorescent detection of glyphosate in fruits and vegetables is constructed by using the prepared oxalic acid carbon dot nanometer enzyme, acetylcholinesterase, acetylcholine, 3,3',5,5'-tetramethyl benzidine and H2O2. The oxalic acid carbon dot nanometer enzyme is prepared by doping ferric nitrate and tetraethylenepentamine with oxalic acid as a precursor, has excellent peroxidase-like activity, and a colorimetric and fluorescent double-mode detection method for glyphosate is constructed by using the oxalic acid carbon dot nanometer enzyme, the double-mode detection results can be verified with each other, and the accuracy and reliability of the detection results are significantly improved.

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 application discloses a microbial nano-enzyme probe, a method for detecting salbutamol and application, and comprises a salbutamol monoclonal antibody and a signal carrier, wherein the signal carrier is a yeast cell loaded with iridium oxide nanoparticles. The application firstly constructs a probe by using a yeast cell loaded with iridium oxide nanoparticles in the detection of an immunochromatographic test strip, uses [3, 3', 5, 5' tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2)] as a substrate to trigger a color developing reaction, can realize high-sensitivity target detection, and the detection limit is as low as 0.012 ng / mL, which is 55 times higher than the sensitivity of a traditional gold-labeled test strip. In addition, the application has a good application prospect, can provide a universal platform for sensitive, accurate and rapid detection of food-borne stimulants, and can be successfully applied to the detection of salbutamol in pig liver and beef samples.

This invention discloses Ni-Fc MOF nanomaterials as Hg 2+ The application of the detection probe, the preparation method of the Ni-Fc MOF nanomaterial includes: 1,1-ferrocene dicarboxylic acid and water-soluble Ni at 110–130 °C. 2+ The Ni-Fc MOF nanomaterials were prepared by salt reaction. This invention is based on Hg... 2+ Sensitive and selective activation of oxidase activity by probes from flower-shaped Ni-Fc MOF nanomaterials was achieved, and a Hg assay was established using flower-shaped nanozymes as recognizers and 3,3',5,5'-tetramethylbenzidine as a signal generator. 2+ Colorimetric sensing method.

The invention provides a method for detecting the total antioxidant capacity of saliva based on iron-based MOF nano-enzyme, and belongs to the field of biosensing. The method comprises the following steps: obtaining an MIL-53Fe nano enzyme; the preparation method comprises the following steps: mixing a diluent of MIL-53Fe nano-enzyme, a sodium acetate buffer solution, 3, 3 ', 5, 5'-tetramethyl benzidine and hydrogen peroxide for reaction, adsorbing a reaction solution by using filter paper, drying and curing by using a chitosan solution to obtain the visual microfluidic detection paper-based chip. Establishing a standard curve of the chromatic value and the ascorbic acid concentration; dropwise adding the treated saliva sample onto the paper-based chip, standing for reaction to obtain a chromatic value, and calculating according to the standard curve to obtain the total antioxidant capacity value of the saliva. Complex matrix interference is broken through, the detection sensitivity and portability are improved, and therefore clinical application of saliva TAC detection in noninvasive health monitoring is promoted.

The invention discloses a nanogold and wood composite material, a preparation method, application and a method for determining the content of glucose in reconstituted tobacco, glucose oxidation is directly catalyzed through the nanogold and wood composite material (AuNPs and wood), the glucose and tetramethyl benzidine (TMB) are subjected to a chromogenic reaction, and the content of the glucose in the reconstituted tobacco is determined by combining the linear relation between absorbance and the glucose concentration. And whether the glucose exists in the reconstituted tobacco and the concentrated solution sample or not and the specific content of the glucose can be accurately judged. The method provided by the invention can quickly obtain a detection result within 30 minutes, is suitable for efficiently screening reconstituted tobacco and concentrated solution samples with the glucose content lower than 0.01 gL <-1 >, can accurately determine the actual content of glucose in the reconstituted tobacco and the concentrated solution, does not need to depend on a standard substance or carry out modeling maintenance, and is simple and convenient to operate. The equipment cost is obviously reduced; and the operation process is simplified.

The invention discloses a colorimetric-fluorescence dual-mode detection method for salmonella and escherichia coli, and belongs to the technical field of biological detection. According to the invention, concanavalin A (ConA) is coupled with magnetic nanoparticles (MNPs) to form MNPs (at) ConA as a capture probe by recognizing the characteristic of capturing bacteria by sugar residues, and in addition, an antibody (Ab) can specifically recognize bacteria and is coupled with quantum dots (QDs) to form QDs (at) Ab as a fluorescence signal probe. The invention finds that MNPs can catalyze 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) to generate blue oxTMB which can be observed by naked eyes; and the QDs have strong fluorescence and can also be observed by naked eyes, so that obvious distinguishing is realized in Sal and Esc detection. And the signal is linearly related to the target bacteria, so that the visibility is good. The practicability of the method is verified by detecting milk tea, milk and fruit juice samples, and the recovery rate is 93.5-106%. The feasibility of detecting Sal and Esc by the method is verified, and the method has important application potential in food safety monitoring.

The application belongs to the technical field of sensors and relates to an array sensor based on cerium-based metal organic framework nanoscale enzyme and detection application of perfluoroalkyl compounds. The array sensor is a Ce-MOF triple enzyme activity array sensor and has multiple independent sensing channels. The sensing channels contain Ce-MOF nanoscale enzyme and chromogenic substrate. The chromogenic substrate includes first, second and third chromogenic substrates. The first chromogenic substrate includes 3,3',5,5'-tetramethylbenzidine. The second chromogenic substrate includes 2,4-diamino phenol and 4-aminoantipyrine. The third chromogenic substrate includes xanthine, xanthine oxidase and nitrogen blue tetrazolium. The MOF nanoscale enzyme array sensor constructed by the application has high sensitivity and selectivity in the identification and differentiation of PFASs compounds. The array sensor can not only accurately distinguish single PFASs compounds but also quantitatively detect the compounds, and has good response to PFASs with different concentrations.

The application discloses a method for colorimetric and photothermal dual-mode detection of aflatoxin B1 in coffee based on MXene@Pt nanozyme, wherein MXene is obtained by etching Ti3AlC2 with LiF and HCl, dopamine carbon dots and sodium borohydride are used as reducing agents, and in-situ reduction technology is adopted to synthesize MXene nanozyme modified with platinum nanoparticles (MXene@Pt). The MXene@Pt shows peroxidase-like activity and photothermal performance enhanced by near-infrared light stimulation, can catalyze the blue deepening of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) and temperature rise, and when aflatoxin B1 exists, the POD-like activity of the MXene@Pt nanozyme is inhibited, and the colorimetric and temperature signals are reduced. The colorimetric and temperature dual-mode sensor detection method for AFB1 is established, and the method has the characteristics of high sensitivity, strong specificity, simple operation, rapidness and the like.

The application discloses a kit for detecting transferrin and application thereof, and belongs to the technical field of transferrin content detection. The kit comprises a PBA-SiO2@Fe3O4 magnetic affinity probe and an Ab-Au, Pt, Cu@PDA nanoscale enzyme immune probe. When the transferrin exists, the PBA-SiO2@Fe3O4 magnetic affinity probe and the Ab-Au, Pt, Cu@PDA nanoscale enzyme immune probe are combined with the transferrin to form a sandwich structure similar to a sandwich. The catalytic performance of the Ab-Au, Pt, Cu@PDA nanoscale enzyme and the Raman enhancement activity of Au, Pt and Cu metal are utilized to make the substrate produce an oxidation product 3,3',5,5'-tetramethyl benzidine diimine with color developing capability, a novel transferrin multi-mode sensing platform with rapidness, sensitivity, selectivity and high reliability is established, and the visual sensing analysis can realize rapid semi-quantitative on-site detection of transferrin in samples. The method can be applied to on-site rapid detection of low-concentration transferrin in sweat, blood, urine and other samples.

The invention belongs to the technical field of biosensors, and discloses a preparation method and application of a polyacid / hydrotalcite composite mimic enzyme. According to the invention, the P2W18O62 / CoAl-LDH composite material is prepared and is applied to the colorimetric reaction process of 3, 3 ', 5, 5'-tetramethyl benzidine, so that the detection of H2O2 and AA is realized. AA can be used as a reducing agent in the system and can reduce blue oxTMB into colorless TMB. On the basis, a rapid and sensitive TMB / H2O2 / P2W18O62 / CoAl-LDH colorimetric sensing system is established to detect the AA. The linear detection range of AA is 10 to 50 mol / L, and the detection limit is 12.5 mol / L. The sensing system shows excellent selectivity, and the TMB / H2O2 / P2W18O62 / CoAl-LDH sensing system is used for detecting the AA in an actual fruit sample.

The application discloses a preparation method of copper-6-mercaptopurine metal organic gel and application thereof in perfluorooctyl sulfonic acid detection, and belongs to the technical field of optical sensing, wherein the preparation method takes 6-mercaptopurine as a reducing agent and a complexing agent, and prepares copper-6-mercaptopurine metal organic gel through a hydrothermal method. The copper-6-mercaptopurine metal organic gel prepared by the application has very high peroxidase-like activity, can efficiently catalyze a substrate 3,3',5,5'-tetramethylbenzidine (TMB) to generate an oxidation product TMB (oxTMB) in the presence of H2O2, and thus can be used as a novel peroxide mimicking nano-enzyme. The application also discloses a colorimetric sensor based on the above copper-6-mercaptopurine metal organic gel and used for perfluorooctyl sulfonic acid detection.

The invention provides a multifunctional nano material Ni-MoS2 (at) Au for detecting trace toxic substances in mushrooms and a preparation method of the multifunctional nano material Ni-MoS2 (at) Au. The nano material is prepared from a metal oxide, a surfactant, precious metal nano particles and a solvent, the nano material has colorimetric and Raman detection functions on various trace toxic substances (mercury ions and amanita peptide) in mushrooms, hydrogen peroxide is immediately catalyzed to quickly oxidize 3, 3 ', 5, 5'-tetramethyl benzidine into yellow 3, 3 ', 5, 5'-tetra (tetrafluoromethyl) phenyl diamine oxide after the nano material is in contact with a target object Hg < 2 + > for 1s in a colorimetric mode, the nano material has an extremely low detection limit of 0.036 mu g / mL, and the nano material can be used for detecting various trace toxic substances (mercury ions and amanita peptide) in mushrooms. The catalyst has good selectivity and is not interfered by other heavy metal ions; in a Raman mode, high-sensitivity detection of alpha-amanita peptide and beta-amanita peptide can be realized, and the detection limit ranges are 10 <-4 > M to 10 <-8 > M. The nano material provides a reference mode capable of detecting multiple target objects in the same system, and opens up a new way for a detection strategy of trace toxic substances in the field of food safety detection.

The present invention discloses a preparation method of a dual-mode sensor for detecting hydrogen sulfide based on fluorescent nanometal organic framework materials. The method adopts a solvothermal method, wherein metal ions or clusters and organic ligands are mixed in a high-boiling-point solvent and reacted to generate MOF under high temperature conditions. The solid polymer synthesized by this method is composed of the metal ion ammonium cerium nitrate and the organic ligand 2-hydroxyterephthalic acid. The sensor is composed of Ce-MOF, 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 to form a colorimetric and fluorescent dual-response sensor. Based on ultraviolet absorption and fluorescence intensity, H2S is accurately detected. The detection range of the sensor colorimetric response is 200-2300μM, with a detection limit of 0.262μM, and the detection range of the fluorescence response is 16-320μM, with a detection limit of 0.156μM, achieving more accurate detection of H2S and meeting the detection requirements of food freshness and safety.

The present application relates to a kind of stable high-efficiency HRP enzymatic green display dye and its preparation method, belong to the field of immunoassay technology, including A liquid and B liquid, A liquid includes ammonium molybdate, polyethyleneimine, alginic acid, sodium pyrophosphate, H2O2 and PB buffer solution;B liquid includes N, N-dimethylformamide, ethylene glycol, N-methyl pyrrolidone, 3, 3', 5, 5'-tetramethyl benzidine hydrochloride hydrate and ethylenediaminetetraacetic acid disodium, when using, A liquid and B liquid are mixed, and green display dye mixed solution is formed.The substrate dye of the present application can form high contrast with brown in double staining, and the sensitivity is high, the staining on quality and membrane positioning is clear and accurate, and also can make long-term, stable preservation of staining result, meet the pathological diagnosis demand of immunohistochemical double staining.

The invention discloses a silk fibroin-based glucose detection platform preparation method, which comprises: mixing cyclodextrin and deionized water to form a homogeneous solution, adding a buffer solution to adjust the pH value range to 4-8, adding 3, 3 ', 5, 5'-tetramethyl benzidine, and uniformly mixing under a dark condition to prepare a 3, 3 ', 5, 5'-tetramethyl benzidine cyclodextrin solution; uniformly mixing a structure regulator with the silk fibroin solution to form a homogeneous precursor solution; uniformly mixing the precursor solution with glucose oxidase, horse radish peroxidase and the 3, 3 ', 5, 5'-tetramethyl benzidine cyclodextrin solution to obtain a base solution; pouring the precursor solution on a microneedle mold, and drying and curing at normal temperature to obtain a microneedle tip; the base solution is poured into a mold containing a needle tip to form a base, demolding is conducted after drying, and the silk fibroin-based glucose detection platform is obtained.

The invention belongs to the technical field of analytical chemistry, and relates to ferrous ion detection liquid as well as a detection method and application thereof. The technical problems that in the prior art, ferrous ions are detected by changing surface modifiers of silver nanoparticles, selectivity is insufficient, sensitivity is limited, steps are tedious, detection instruments are complex, and cost is high are solved. The invention provides a ferrous ion detection liquid which comprises tetramethyl benzidine, thiohydracrylic acid and silver nanoparticles, and the ratio of the tetramethyl benzidine to the thiohydracrylic acid to the silver nanoparticles is (1200-6000): (0.005-0.5): 99 according to the mass concentration. The pH value of the detection liquid is 4-6. The detection liquid is high in selectivity and high in sensitivity. The invention provides a preparation method of the ferrous ion detection liquid, and also provides a ferrous ion detection method, which is simple and convenient, is easy to detect, and can rapidly detect micromole-level metal ferrous ions. Meanwhile, the invention further provides application of the ferrous ion detection method in the sensing field and environment monitoring.