1075results about How to "Low detection limit" patented technology

The invention relates to the technical field of optical sensing, in particular to a copper-carbon quantum dot nano-enzyme and a preparation method and application thereof. Poria cocos and Cu < 2 + > are taken as raw materials, and the copper-carbon quantum dots with excellent peroxidase activity are prepared by adopting a one-pot hydrothermal method and can be used for sensitively, accurately and selectively detecting glyphosate. Cu < 2 + > is combined with oxygen-rich and nitrogen-rich components in poria cocos to generate an oxidation-reduction reaction, CuCDs with Cu < 2 + > / Cu < + > are obtained, Cu < 2 + > doping changes electron cloud distribution of the CDs, the electron transmission capability of the CuCDs is enhanced, and Cu < 2 + > and the CDs have a synergistic effect to generate three ROS (. OH,. O2 <-> and < 1 > O2), so that excellent peroxidase activity is exerted. The glyphosate is chelated with hydroxyl, amino, carbonyl, carboxyl and Cu on the surface of the CuCDs to occupy active sites, so that the active sites are poisoned, the peroxidase activity of the CuCDs is selectively inhibited, and a powerful choice is provided for simply, quickly, sensitively and selectively detecting the glyphosate.

A linear response stretchable resistance strain sensor belongs to the technical field of wearable sensors, is of a three-layer film structure and comprises a stretchable elastic substrate, a middle strain sensitive layer and a stretchable elastic package on the uppermost layer. The nano conductive material network bonded by the trace polymer not only has high conductivity close to that of a pure nano conductive material, but also enhances the mechanical stability of the conductive network. Uniform and random cracks are formed after primary stretching, and a stable structure similar to a plane spring is formed. The strain of the measured object drives the size of the air gap in the crack to change, and the conductive path is changed, so that the resistance is changed. The invention shows the detection capability of the sensor in a strain range of 0.001% to 100%, hysteresis (1.61%), linear response, fast enough reaction speed and extremely low residual resistance. The strain sensor also has stability, pressure insensitivity and waterproofness, and is suitable for long-term accurate monitoring of strain of soft systems such as biological tissues in the field of medical health.

The invention discloses a construction method and application of an electrochemical luminescence (ECL) antifouling sensor based on zwitter-ion hydrogel, and belongs to the technical fields of photoelectric sensing analysis, interface antifouling and environmental science. According to the invention, the hydrogel based on sulfobetaine methacrylate zwitterions and bovine serum albumin is used as the antifouling coating, so that the adsorption of biological proteins and bacteria is effectively hindered, and the service life of the sensor is prolonged. Meanwhile, the interior label Au (at) luminol is packaged in the antifouling hydrogel, so that the integration of interface antifouling and ratio detection is realized, the detection accuracy is improved, and the construction process of the ECL sensor is simplified. The constructed ECL anti-pollution sensor has high sensitivity to chloramphenicol detection, the detection limit is 0.39 pM, and the ECL anti-pollution sensor is suitable for trace detection of antibiotics in seawater.

The invention discloses a membrane electrode for a fuel cell type H2 gas sensor and a preparation method thereof. The preparation method comprises: adding SnO2 powder or SnO2-Pd powder to a chloroplatinic acid solution and adding sodium citrate and stirring to obtain a substance A; adding a sodium borohydride alkaline solution to the substance A under ice-water bath conditions, heating in a water bath at 60-90°C for 1-2h to obtain a substance B; centrifuging and washing the substance B, and drying to obtain a target powder, wherein the target powder is Pt / SnO2 powder or Pt / SnO2-Pd powder, wherein Pt / SnO2 is SnO2 modified by Pt nanoparticles, and Pt / SnO2-Pd is SnO2-Pd modified by Pt nanoparticles, and the mass ratio of Pt to SnO2 in the target powder is in the range of #imgabs0#. After the target powder is configured into an electrode slurry, an electrode layer is prepared by using the electrode slurry and adhered to both sides of a Nafion membrane to form a membrane electrode. Assembling the membrane electrode into the fuel cell type H2 gas sensor structure can greatly improve the sensor's detection sensitivity to hydrogen and reduce the sensor's detection limit.

The invention relates to a preparation method of a zeolite imidazole frame-8 double-site loaded carbon dot and gold or gold and silver nanocluster fluorescent material, which comprises the following steps of: 1, uniformly mixing a HAuCl4 aqueous solution and a GSH aqueous solution at room temperature, or uniformly mixing an AgNO3 aqueous solution, the HAuCl4 aqueous solution and the GSH aqueous solution, then stirring for 20-28 hours at 60-80 DEG C, cooling to room temperature, adding methanol, centrifuging, and drying to obtain a precursor solution of the zeolite imidazole frame-8 double-site loaded carbon dot and gold or gold and silver nanocluster; washing and drying to obtain gold or gold-silver nanoclusters, and dispersing the gold or gold-silver nanoclusters in water for later use; step 2, preparing carbon dots CDs; 3, zinc nitrate hexahydrate and 2-methylimidazole are added into methanol containing CDs under the stirring condition to react for 20-28 hours, centrifugation and washing are conducted, and a product ZIF coated CDs is obtained; and 4, mixing the gold or gold and silver nanocluster solution with the ZIF-coated CDs under an ultrasonic condition at room temperature to obtain the ZIF-coated CDs / gold / silver nanocluster composite material. The invention also provides an application of the zeolite imidazole frame-8 double-site loaded carbon dot and gold and silver nanocluster fluorescent material in detection of pesticide triazophos (TZP) and glucose.

The invention relates to the technical field of preparation of solid-phase microextraction devices, and particularly discloses a pretreatment method and analysis application of a quinolone antibiotic sample, a conjugated microporous polymer (CMP) is successfully prepared by adopting a SonogashiraHagihara cross-coupling reaction, and a cationic conjugated microporous polymer CMP-I is obtained by further carrying out methylation treatment on the CMP by using CH3I. According to the present invention, the cationic CMP-I is adopted as the solid phase extraction adsorption material to construct the solid phase microextraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS / MS) analysis method, and the method has characteristics of high sensitivity and low detection limit in the QA detection aspect, and can meet the accurate determination requirement of the trace QA in meat and water.

The invention relates to a preparation method and application of a novel lactic acid detection fluorescent probe, and belongs to the technical field of fluorescent probes. The preparation method of the fluorescent probe comprises the following steps: synthesizing a core-shell type up-conversion nano material CS-UCNPs; carrying out surface modification on the core-shell type up-conversion nano material CS-UCNPs; coupling of the core-shell type up-conversion nano material CS-UCNPs and an L-lactic acid aptamer is carried out; and synthesizing the magnetic molybdenum disulfide nanosheet MoS2. The L-lactic acid aptamer, the core-shell UCNPs and the magnetic MoS2 are combined for high-sensitivity detection of the lactic acid content, and compared with a traditional blood lactic acid detection method, the method has the advantages of being non-invasive, non-invasive and the like; and the technology has the advantages of simplicity in operation, high specificity, quick response and the like, has a wider detection range and a lower detection limit, and is expected to be applied to actual sample detection work.

The invention discloses a construction method and application of a ratio-dependent electrochemical luminescence (ECL) biosensor based on an antifouling red cell membrane, and belongs to the technical fields of photoelectric analysis, biosensing and interface antifouling. In the invention, the erythrocyte membrane with super-hydrophilicity and low membrane protein content is used as an efficient antifouling interface, and the good biocompatibility of the erythrocyte membrane avoids the influence of a chemical antifouling coating on the biological activity of the ECL sensor. Meanwhile, the electropolymerized polyaniline nanowire is embedded into the antifouling erythrocyte membrane, so that the chemical stability and the conductivity of the antifouling erythrocyte membrane are enhanced, and the application of the antifouling erythrocyte membrane in ECL analysis is expanded. C3N4 is introduced as an interior label for eliminating background signals and external interference, so that the detection precision of the biosensor is improved. On the basis, the constructed ECL antifouling biosensor realizes ultra-sensitive detection of human breast cancer cells MCF-7 in human serum, and the detection limit is as low as 3 cells / mL.

The invention relates to an SERS (Surface Enhanced Raman Scattering) substrate based on a silver-covalent organic framework heterojunction as well as a preparation method and application of the SERS substrate, and belongs to the technical field of analysis and detection. The SERS substrate based on the silver-covalent organic framework heterojunction comprises an amidoxime group modified covalent organic framework material and silver nanoparticles adsorbed on the amidoxime group modified covalent organic framework material. The COF-TpDb-AO with semiconductor characteristics can improve the Raman signal intensity through a chemical enhancement effect, the silver nanocluster generates a strong electromagnetic enhancement effect, the SERS substrate significantly improves the detection sensitivity (the detection limit is as low as 7.4 * 10 <-9 > mol / L) through the cooperation of electromagnetism and the chemical enhancement effect, and the enhancement factor (EF) is 1.26 * 10 < 6 >.

The invention provides a label-free magnetic self-assembly nanoprobe, a construction method thereof and application of the label-free magnetic self-assembly nanoprobe in detection of PrPC protein. The label-free magnetic self-assembly nanoprobe disclosed by the invention comprises a magnetic Fe3O4 / Fe2O3 (at) Au heteroplasmon nanorod array and a sulfhydrylation aptamer nucleic acid chain which is combined with the magnetic Fe3O4 / Fe2O3 (at) Au heteroplasmon nanorod array through an Au-S bond; a biosensor prepared from the label-free magnetic self-assembly nanoprobe is good in reproducibility and stability; the RSD value of multiple times of detection (intraday / day) is 1.55%; the storage time of multiple groups of sensors is 0-15 days, and the change of response signal values does not exceed 4%; the biosensor has a relatively low detection limit (1pg / mL), a relatively wide linear range (1 * 10 < pg / mL >-1 * 10 < 5 > pg / mL) and relatively good sensitivity, has very good application in detection of PrPC, and has very good practicability.

The invention relates to the technical field of preparation and application of functional materials, in particular to a fullerene / metal organic framework loaded with acetylcholin esterase as well as a preparation method and application of the fullerene / metal organic framework. The preparation method comprises the following steps: firstly, preparing a fullerene / metal organic framework C60-coated PCN-222 (Fe) nano-enzyme with a space limited environment, and providing a self-cascade amplification strategy without external energy input based on the activities of oxidase-like OXD and peroxidase-like POD of the fullerene / metal organic framework C60-coated PCN-222 (Fe) nano-enzyme; then, the C60 atched PCN-222 (Fe) is combined with acetylcholin esterase AChE by means of molecular interaction, and an AChE / C60 atched PCN-222 (Fe) enzyme-nano enzyme array flow reactor is further developed. The sensor realizes parallel real-time detection and distinguishing of a plurality of organophosphorus pesticides, and has the advantages of wide linear range, high sensitivity and low detection limit. A promising strategy is provided for design of a nano-enzyme and trace pollutant detection system, and a sensing platform is stable in performance, low in price and convenient for commercialized application.

The invention discloses a pyrenyl Schiff base fluorescent derivative, a fluorescent probe, a preparation method of the pyrenyl Schiff base fluorescent derivative and application of the pyrenyl Schiff base fluorescent probe in biological imaging, and belongs to the technical field of fluorescent probes. The pyrenyl Schiff base fluorescent probe capable of specifically detecting the zinc ions is prepared through two-step chemical reaction of Suzuki coupling reaction and aldehyde amine condensation reaction, and the pyrenyl Schiff base fluorescent probe has good recoverability and low cytotoxicity, is high in practicability and low in cost, and can be applied to detection of the zinc ions. In addition, the sensor has excellent ion selectivity to zinc ions, extremely high sensitivity, good Stokes displacement and visual sensing performance, and detection of exogenous zinc ions and endogenous zinc ions in cells and tissues is realized through biological imaging. The problems of difficult synthesis process, slow response speed, high detection cost, non-ideal biological imaging effect and the like of the conventional fluorescent derivative are solved.

The invention discloses a titanium-doped lamellar FER molecular sieve and application thereof in a rutin electrochemical sensing detector, and belongs to the technical field of molecular sieve synthesis and electrochemical sensor detection. The titanium-doped lamellar FER molecular sieve is prepared by taking an organic compound as a template agent through a hydrothermal method. The structural formula of the organic compound is NH2-C2H4-NH-(CH2) n-O-(p-C6H4) 2-O-(CH2) n-NH-C2H4-NH2, and the structural formula of the organic compound is NH2-C2H4-NH-CH2. Wherein n ranges from 10 to 16. The preparation method comprises the following steps: immobilizing chitosan on a titanium-doped lamellar FER molecular sieve to obtain a composite material, and modifying an electrode by adopting the obtained composite material to construct an electrochemical sensor; the obtained electrochemical sensor is used for detecting and analyzing rutin. The rutin detection concentration linear range of the obtained electrochemical sensor reaches 0.1-10 [mu] mol / L, the concentration detection range is wide, the detection sensitivity, accuracy, repeatability and selectivity are high, the detection lower limit is low, and the stability is good.

The invention discloses a detection method and application of whole genome 5-hydroxymethylcytosine, and relates to the technical field of biochemical detection. Comprising the following steps: 1, closing a 3 '-OH end of DNA to be detected; 2, preparation of glycosylated 5hmC DNA (Deoxyribose Nucleic Acid); 3, carrying out TdT mediated DNA (Deoxyribonucleic Acid) amplification; and 4, fluorescence measurement. According to the invention, a homogeneous and non-template dependent type signal amplification method for detecting the 5-hydroxymethylcytosine in the whole genome is constructed. The method is based on a specific enzyme catalytic reaction and a multiple signal amplification strategy, and has the characteristics of high sensitivity, good specificity, no need of a separation step, no sequence dependence in amplification and capability of detecting 5hmC at any position in a whole genome. In addition, accurate and sensitive detection of actual clinical samples can be realized.

The invention discloses a double-recognition fluorescent molecular probe, a preparation method thereof and application of the double-recognition fluorescent molecular probe in detection of lead ions and / or glyphosate, and relates to the technical field of detection of lead ions and pesticide glyphosate. The double-recognition fluorescent molecular probe disclosed by the invention is a Schiff base type probe which takes dicyanoisophorone and benzoyl hydrazine as fluorophores. The invention also relates to application of the double-recognition fluorescent molecular probe in lead ion sensing detection. The complex of the double-recognition fluorescent molecular probe and lead ions can be used for sensing detection of glyphosate. The double-recognition fluorescent molecular probe provided by the invention has the advantages of easily available raw materials and simple operation. According to the present invention, the quantitative detection of the lead ions / or the glyphosate by the probe through the different functions displayed by the ultraviolet and fluorescence spectra is achieved, the reversibility is strong, the multi-time cyclic utilization can be achieved, the selectivity is good, the influence by other metal ions is not easily generated, the detection limit is low, and the excellent application imaging is provided in animal bodies such as cells, zebra fish and the like.

The invention discloses a preparation method of a carbon dot nano-enzyme, which comprises the following steps: dissolving oxalic acid, polyethyleneimine and ferric nitrate in ultrapure water, heating, mixing and reacting, cooling to room temperature, centrifuging, filtering, dialyzing, and taking supernate to obtain the carbon dot nano-enzyme. The prepared oxalic acid carbon dot nano-enzyme is matched with acetylcholin esterase, acetylcholine, 3, 3 ', 5, 5'-tetramethyl benzidine and H2O2 to construct a colorimetric and fluorescent dual-mode detection method for glyphosate in fruits and vegetables. The oxalic acid carbon dot nano-enzyme is prepared by doping ferric nitrate and tetraethylenepentamine into oxalic acid serving as a precursor, the oxalic acid carbon dot nano-enzyme has excellent peroxidase-like activity, a colorimetric and fluorescent dual-mode detection method of glyphosate is constructed through the oxalic acid carbon dot nano-enzyme, dual-mode detection results can be mutually verified, and the detection result is accurate. And the accuracy and the reliability of a detection result are remarkably improved.

The invention belongs to the technical field of high polymer materials, and particularly relates to an environment-friendly material for soil detection and a preparation method thereof. The preparation method of the material comprises the following steps: (1) preparing carboxylated nano cellulose fiber dispersion liquid; (2) preparing a mixed solution of polyethylene glycol and curcumin; (3) dropwise adding the mixed solution into the carboxylated nano cellulose fiber dispersion liquid; and (4) putting in a light-proof acidic steam environment for gelation, and freeze-drying to obtain the environment-friendly material for soil detection. The gel can specifically detect and adsorb lead ions, and has the advantages of high sensitivity, no contact pollution and the like. The method is especially suitable for specific detection of lead ions in soil containing various metal ions. And the material is in a solid state, is convenient to store and transport and has a wide application prospect.

The invention relates to the field of environmental engineering and waste recycling, in particular to a method for detecting and recycling copper ions through carbon dots, amines and acids are used as precursors, the carbon dots with fluorescence are prepared through a microwave-assisted thermal method, the prepared carbon dots are used for quantitative fluorescence sensing and flocculation recycling of II-valent copper ions, and the method for detecting and recycling the copper ions through the carbon dots is suitable for industrial production. The higher the concentration of the II-valent copper ions is, the lower the fluorescence intensity is, a standard linear relation exists between the two, in addition, the obtained carbon dots can also be combined with the II-valent copper ions to form a complex to generate flocculation and calcination to obtain copper oxide, and the II-valent copper ions in the waste are recycled; the preparation method of the carbon dots is simple and efficient, large-scale batch preparation can be achieved, the carbon dots can achieve accurate detection of the II-valent copper ions, the detection limit is extremely low, accurate separation and extraction of the II-valent copper ions can be achieved, the recovery efficiency is high, the cost is low, and practicability is high.

The invention discloses an ionic liquid flexible strain sensor based on a mechanical metamaterial and a preparation method of the ionic liquid flexible strain sensor. The sensor comprises two packaging layers, a flow channel layer and a mechanical metamaterial structure layer, the mechanical metamaterial structure layer is used for regulating and controlling a micro-column gap in a micro-flow channel of the flow channel layer so as to regulate and control the performance of the ionic liquid flexible strain sensor, the mechanical metamaterial structure layer is packaged in the packaging layers, the packaging layers are attached to the flow channel layer in a sealed mode, and the flow channel layer is filled with ionic liquid. Firstly, a mechanical metamaterial structure layer is obtained through a 3D printer and resin material printing; then preparing a packaging layer packaged with a mechanical metamaterial structure layer through a PDMS (Polydimethylsiloxane) mixed solution; finally, the packaging layer and the flow channel layer are attached and filled with an ionic liquid solution, sealing is conducted after a wire is inserted, and finally the ionic liquid flexible strain sensor is prepared and obtained. The flexible strain sensor has the characteristics of high sensitivity, wide range, low detection limit, adjustable Poisson ratio and the like, and can be suitable for receiving and monitoring strain signals in various scenes.

The invention belongs to the technical field of X-ray detection, and particularly relates to lead-free two-dimensional double perovskite, a preparation method of the lead-free two-dimensional double perovskite and an X-ray detector manufactured based on the perovskite. The lead-free two-dimensional double perovskite is applied to X-ray detection. According to the preparation method, histamine dihydrochloride (C5H11Cl2N3Cl), silver chloride (AgCl) and bismuth trioxide (Bi2O3) are mainly used as raw materials, a mixed solution of hydrobromic acid (HBr) and hypophosphorous acid (H2PO2) is used as a solvent, a single crystal material ((C5H9N3) 2AgBiBr8 single crystal) is prepared through a hydrothermal method, and the two sides of the single crystal are coated with silver paste to serve as electrodes, so that the direct type X-ray detector is obtained. The preparation method disclosed by the invention has the characteristics of simplicity, easiness in operation, low requirement on equipment, low cost, low energy consumption and suitability for expanded production.

The invention discloses a method for yeast-assisted synthesis of porous carbon / vanadium sulfide nano-enzyme and application of the porous carbon / vanadium sulfide nano-enzyme in serum creatinine detection, and belongs to the technical field of serum creatinine detection. Comprising the following steps: (1) mixing saccharomycetes, vanadium chloride and ethanol, performing ultrasonic dispersion, and stirring until liquid is completely volatilized to obtain a first solid A; (2) mixing and grinding the first solid substance A, potassium carbonate and potassium chloride to obtain a second solid substance B; (3) respectively placing the second solid substance B and thioacetamide in grooves at the left end and the right end of a Joule thermal device graphite sample table, and carrying out rapid Joule thermal shock to obtain a third solid substance C; and (4) washing and drying the third solid C to obtain the porous carbon / vanadium sulfide nano-enzyme. A colorimetric sensing method is constructed based on the nano-enzyme prepared by the invention, is used for creatinine detection, and has extremely low detection limit, LOD is as low as 0.07 M / mL, and high specificity and sensitivity are embodied.

The invention discloses a polymer fluorescent sensing film for detecting a neurotoxic agent sarin simulant as well as a preparation method and application of the polymer fluorescent sensing film. The polymer fluorescent sensing film is prepared by crosslinking an acylhydrazone bond formed by bis-p-phenylene dihydrazide connected with a polyethylene glycol chain and tetraphenyl ethylene terephthalaldehyde through a Schiff base reaction. The polymer fluorescent sensing film has the excellent properties of both the polyethylene glycol chain and the tetraphenyl ethylene, the introduction of the polyethylene glycol chain enables the film to have more excellent flexibility, and the introduction of the tetraphenyl ethylene enables the film to have richer luminescent properties and better photochemical stability. The polymer fluorescent sensing film shows ultra-sensitive, high-selectivity, rapid and recoverable response to a nerve toxic agent sarin simulant diethyl chlorophosphate, has a detection limit of 1 ppt for diethyl chlorophosphate, has high anti-interference capability for hydrochloric acid and other volatile organic compounds, and can be used for detecting the nerve toxic agent sarin.

The invention belongs to the technical field of nano material detection, and particularly discloses a method for detecting Cr (VI) by using a double-lanthanide metal organic framework Eu / Tb MOF ratio fluorescence sensor, which comprises the following steps: screening and preparing a lanthanide metal organic framework Eu / Tb MOF using 1, 3, 5-dicarboxyphenylboronic acid as a ligand; and 2, detecting Cr (VI) by using an Eu / Tb MOF ratio fluorescence sensor. The Cr (VI) enables the fluorescence absorption peak of the Eu / Tb MOF to be quenched at 545nm and the fluorescence absorption peak of the Eu / Tb MOF to be almost unchanged at 618nm, so that the Eu / Tb MOF ratio fluorescence sensor is constructed to detect the Cr (VI), and the concentration of the Cr (VI) in a to-be-detected sample is judged through fluorescence intensity, color change and CIE chromaticity diagram degree. The Eu / Tb MOF ratio fluorescence sensor can generate more color intervals, Cr (VI with different concentrations can be detected more accurately, and the sensitivity is improved. The method disclosed by the invention has the characteristics of low cost, high response speed, low detection limit and high sensitivity and selectivity.

The invention provides a method for detecting related substances in a tandospirone citrate product, which adopts high performance liquid chromatography and can effectively detect the related substances in the tandospirone citrate product. The detection method provided by the invention has the advantages of no baseline interference, high separation degree, low detection limit, strong specificity, high sensitivity, and good accuracy, precision and durability. According to the invention, new compounds, namely a compound IV, Tand-3, Tand-4, Tand-5, Tand-base-4, Tand-base-6 and Tand-base-8, are also found in the invention. The compound can be used as a reference substance for content analysis and / or quality control of a product containing tandospirone citrate or tandospirone.

The invention belongs to the field of biosensing detection, and particularly relates to an ATP (adenosine triphosphate) nucleic acid aptamer based on m6A epigenetic base modification and application of the ATP nucleic acid aptamer. The invention provides a nucleic acid aptamer and a nucleic acid aptamer sensor. On the basis of recognition and binding specificity of a nucleic acid aptamer probe to a target, a single-point methylation closed switch type functional probe is constructed, and living cell and living body imaging detection of endogenous demethylase is realized. Taking ATP and an aptamer thereof as an example, m6A methylation modifies key sites of the aptamer so as to influence the binding stability between the aptamer and a ligand, after endogenous FTO demethylation, the aptamer recovers active sites, can be rapidly bound with ATP and is driven to allosteric to release fluorescence, and in-situ instant detection of FTO is realized.

The invention relates to the technical field of electrochemical sensing, in particular to an MXene-coated MB / PtNPs electrochemical sensor and a preparation method thereof and a carbendazim detection method, MXene is used as a carrier, PtNPs is embedded between layers and on the surface of MXene through reduction reaction, then electroactive molecules MB are introduced through electrostatic interaction, an MXene-coated MB / PtNPs composite material is formed, and the MXene-coated MB / PtNPs electrochemical sensor is prepared. And then modifying a glassy carbon electrode by using the MXene coated MB / PtNPs composite material to prepare the MXene coated MB / PtNPs electrochemical sensor. The compound is used as a ratio electrochemical sensor for detecting carbendazim, the linear range of the compound to carbendazim is 10-30000 ng / mL, the detection limit is 3.3 ng / mL, the detection speed is high, the sensitivity is high, the linear range is wide, the precision is high, the detection limit is low, meanwhile, the anti-interference performance and repeatability are good, and the compound has potential application prospects in the field of agricultural product quality detection.

The invention discloses a quantitative detection method for multi-element heavy metals in tobacco flavor. According to the method, to-be-detected heavy metal elements in the essence are calibrated through a multi-element heavy metal standard solvent to obtain a standard curve, and through multiple times of test fitting, the influence of background noise on result accuracy is eliminated, and the detection limit is effectively reduced, so that the test sensitivity is improved; the co-soluble solvent is adopted to effectively eliminate the influence of different substrates in the perfume, and the problem of local abnormality caused by inconsistent dissolution backgrounds is solved. The method has the advantages of simple sample pretreatment, high detection speed, high accuracy and the like, can significantly improve the detection capability and efficiency of heavy metals in the essence and perfume sample, and effectively ensures the quality and safety of the essence and perfume sample.

The invention relates to the field of photoelectric sensors, in particular to a photoelectric sensor based on a bismuth sulfide composite material and application of the photoelectric sensor in norfloxacin detection, and a preparation method of the photoelectric sensor comprises the following steps: preparing the bismuth composite material; modifying the bismuth composite material with gold nanoparticles; modifying a fluorine-doped tin oxide glass electrode; the photoelectric sensor provided by the invention is combined with the gold nanoparticle sol, and an electric field formed by surface plasmon resonance accelerates the migration of electrons, enhances the optical absorption of the whole material and improves the photoelectric response. The photoelectric signal intensity has a good linear relationship with the concentration of norfloxacin in a certain range, so that the method has good reproducibility and relatively high detection sensitivity, can realize effective detection of norfloxacin, and has good application value and application prospect in the fields of environment, biology, medicine and the like.

The invention provides a zinc oxide-zinc ferrite hollow nanoflower composite material as well as a preparation method and application thereof, and belongs to the technical field of gas sensitive materials. The preparation method comprises the following steps: precipitating zinc acetate, polyvinylpyrrolidone and potassium ferricyanide at room temperature by adopting a chemical precipitation method to obtain solid Zn3 [Fe (CN) 6] 2 nanoparticles; the preparation method comprises the following steps: taking Zn3 [Fe (CN) 6] 2 nanoparticles as a template reactant, etching the Zn3 [Fe (CN) 6] 2 nanoparticles in water-N, N-dimethylformamide to obtain a ZnFe precursor, and carrying out high-temperature calcination treatment on the precursor to obtain the zinc oxide-zinc ferrite hollow nanoflower structure composite material. The ZnO / ZnFe2O4 composite material prepared by the method disclosed by the invention is good in morphology and relatively large in specific surface area, and is of a hollow nanoflower spinel structure. The structure has potential application value in the field of gas sensors, and a new thought is provided for expanding the application of the spinel type semiconductor oxide serving as a sensitive material to construct the gas sensors.

The invention discloses a bimetallic / carbon nanotube compound modified glassy carbon electrode as well as a preparation method and application thereof, and belongs to the technical field of electrochemical analysis. The bimetallic / carbon nanotube compound modified glassy carbon electrode provided by the invention comprises a glassy carbon electrode substrate and a bimetallic / carbon nanotube compound compounded on the glassy carbon electrode substrate, the bimetallic / carbon nanotube compound is prepared from nickel-cobalt bimetallic nanoparticles and a multi-walled carbon nanotube. The prepared bimetallic / carbon nanotube compound modified glassy carbon electrode has excellent electrocatalytic activity, has the advantages of good stability, low detection limit and high sensitivity and selectivity in the process of determining paracetamol, can realize on-site rapid detection of paracetamol, has the advantages of being convenient to carry and simple to operate, and has a wide application prospect. Wide application prospects are realized in medicine safety and clinical medical treatment.