92results about How to "Implement selective detection" patented technology

The invention belongs to the technical field of electrochemical biosensors, and discloses a hydrogen peroxide biosensor based on sulfonated carbon nanotube composited with horseradish peroxidase, preparation and application thereof. The biosensor is composed of a reference electrode, a counter electrode and a modified working electrode, the modified working electrode is composed of a working electrode and a substance recognition film solidified on the surface of the working electrode, wherein the substance recognition film is mainly composed of a sulfonated carbon nanotube dispersion, a horseradish peroxidase solution and a perfluorosulfonic acid resin solution, and formed on the surface of the working electrode. The invention also discloses a method for preparing a sensor. The preparationmethod of the invention is simple and low in cost; the obtained sensor has good selectivity, sensitivity and stability, the enzyme has a fixed quantity and stability, and has good electrocatalytic performance; the hydrogen peroxide biosensor has strong anti-jamming capability, a wide detection range and a low detection limit, and can detect the hydrogen peroxide accurately.

The invention discloses a method for detecting N-acetylaspartic acid by using nuclear spin single-state selectivity. According to the method, the nuclear spin single states of three H atoms prepared on the methylene and methine of the N-acetylaspartic acid are prepared, the observation of selectivity in a complex mixed system for N-acetylaspartic acid signals is realized according to a characteristic that the nuclear spin single states are not influenced by a gradient field. The measurement method has the advantages of high sensitivity, high accuracy, small interference, high selectivity, highreproducibility and the like. The method can inhibit the signals of other related interference substances in a system with complex compositions and finally obtain the signals of the N-acetylasparticacid which are required to be observed; and the method is expected to monitor the content and distribution of the N-acetylaspartic acid in the living body of a living thing and has a high applicationvalues in related production and life fields such as the biology and medicine fields.

The invention discloses a preparation method of a magnetic control induced amaranth molecular targeted electrochemical sensing membrane. The preparation method comprises electrode pretreatment, molecular imprinting self-assembly solution preparation, electro-polymerization reaction and template molecule elution. The method combines the advantages of magnetic induction, an electrochemical sensor and a molecular imprinting technology to construct the magnetic control induced amaranth molecular targeted electrochemical sensing membrane for the first time. The coloring matter amaranth added in foodstuffs is rapidly detected, standardization of behaviors of foodstuff production enterprises is availed, and development of Chinese foodstuff security work is promoted.

The invention belongs to the technical field of biological sensors, and discloses a non-enzyme sensor based on nitrogen-doped graphene and a preparation method and application thereof. The sensor consists of a reference electrode, a counter electrode and a modified working electrode, wherein the modified working electrode consists of a working electrode and a material recognizing membrane cured on the surface of the working electrode, and the material recognizing membrane consists of a nitrogen-doped graphene composite material and perfluorinated sulfonic acid resin. The non-enzyme sensor provided by the invention is applied to the detection of hydrogen peroxide, is wide in detection range, is low in detection limit, and has stable performance and a good application prospect; a reaction is implemented in a neutral environment at the room temperature.

The invention discloses a method for detecting total phosphorus in a water sample based on a composite ratiometric fluorescent probe, and belongs to the technical field of environmental monitoring. According to the invention, a N,S-CQDs/EuCPs composite ratiometric fluorescent probe system is constructed based on a rare earth ionic polymer and carbon quantum dots. Except for slight influence of Fe3 +, other metal cations or inorganic anions have no obviously influence on a fluorescence intensity ratio of the probe, which indicates that the fluorescent probe system can realize a selective detection of phosphate radicals. The method is adopted to measure phosphate radical concentration in tap water, lake water, river water and human urine, and the measured phosphate radical concentration hasgood consistency with the result measured by a phosphomolybdic blue spectrophotometry method.

The invention discloses a method for quantitatively detecting alanine transaminase in a solution based on a copper nanocluster fluorescent probe, wherein a copper nanocluster with glutathione as a protective agent is used as a fluorescent probe, and the content of alanine transaminase in the solution is specifically detected through a fluorescence "off-on" mode. The label-free, highly sensitive and selective detection of alanine transaminase is achieved by adopting the fluorescence "off-on" mode. The method is simple and rapid, the specific detection of alanine transaminase can be realized, the detection linear range is wide, and the detection limit is low. The method in the invention has good detection sensitivity and selectivity and has good application prospects in disease detection, clinical application and other aspects.

The invention discloses a cysteine fluorescent probe and a preparation method thereof. According to the present invention, the fluorescent probe selectively reacts with cysteine, and the acryloyl group is broken, such that the fluorescence emission of the fluorescent group is restored so as to selectively detect the cysteine; due to the strong influence of the electron donor-receptor system on thefluorescent group, the intramolecular charge transfer effect is obvious, and the long-wavelength fluorescence emission and the large Stokes shift can be simultaneously obtained so as to effectively reduce the background interfering signals and improve the imaging quality; and the fluorescent probe has an emission wavelength of 636 nm and a Stokes shift of 158 nm, and has characteristics of high selectivity, high sensitivity and excellent imaging.

The invention discloses a method of selectively detecting thrombin by a phosphorescent probe. The phosphorescent intensity of a system is recovered as Mn doped ZnS phosphorescent quantum dots coated by MPA and a thrombin adapter are mixed with surfaces, far from the quantum dots, of TBA in a quenching system because of relatively high specificity combination between a thrombin adapter (TBA) and thrombin. Related to the phosphorescent quantum dots, the phosphorescent quantum dots are applied more widely in detection as the phosphorescent service life is long, interference of autofluorescence and scattered light can be avoided, the selectivity is high, no deoxidant and inductor are needed to be added during detection and the like. The phosphorescent quantum dots and TBA are not modified, sothat the synthetic steps are simplified to a great extent, and meanwhile, the experimental cost is also lowered. The method is high in accuracy and high in sensitivity, and has a very good applicationprospect in detection of an actual sample.

The invention discloses a preparation method for a cubic nanogold SERS probe used for TNT detection. The preparation method comprises seed crystal gold preparation, further growth and the functional modification and the self assembling of a silicon wafer. The preparation process of the preparation method comprises the following steps that: firstly, preparing seed crystal gold, and enabling the seed crystal gold to further grow; secondly, through a seed growth mechanism, strictly controlling the growth environment of the seed crystal gold to enable the seed crystal gold to grow into a cubic structure; thirdly, modifying sulfydryl on a polished 1*1cm<2> silicon wafer to enable a gold particle monolayer to be assembled to the surface of the silicon wafer on the own; and finally, modifying thesurface of the silicon wafer with electron-rich amino, realizing the selective recognition of the TNT further through a static electricity mutual function with three electron deficiency nitryls in aTNT target molecule, and utilizing a local area plasma resonance field on the surface of the nanogold to amplify and enhance the conventional Raman signal of the TNT molecule so as to realize the trace detection of the TNT, wherein a detection limit is 10<-9>mol.L<-1>. The preparation method has the advantages of being simple in preparation, convenient in operation, low in cost, good in selectivity and high in sensitivity.

The invention discloses a method for adding a gas selection function of a multifunctional gas sensor and the gas sensor. The method for adding the gas selection function of the multifunctional gas sensitive sensor comprises the step of forming a nano noble metal particle modification layer on the surface of a semiconductor gas sensitive material layer of a probe of the gas sensitive sensor, so that the single probe of the gas sensitive sensor can realize selective detection on at least three gases in a working temperature range of 0-400 DEG C. According to the method for adding the gas selection function of the multifunctional gas sensitive sensor, the surface of the semiconductor gas sensitive material layer is modified by using the nano noble metal particles, so that the gas selectivity of the gas sensitive sensor is improved, the types of selected gases are expanded, and selective detection of at least three gases within the working temperature range of 0-400 DEG C can be realized; and a new scheme and a new way are provided for preparing the multifunctional gas sensitive sensor with more gas selection functions.

The invention relates to a large-mesopore tungsten oxide hydrogen sulfide sensitive material with a high specific area and a preparation method thereof. The large-mesopore tungsten oxide hydrogen sulfide sensitive material is characterized by being formed by cubically and periodically arraying tungsten oxide spiral nanowires, the diameter of the nanowires is 3-7 nm, uniform large mesopores of 12 nm are formed, and the specific area is 163m2/g. The large-mesopore tungsten oxide hydrogen sulfide sensitive material has the following advantages of being capable of selectively detecting hydrogen sulfide gas at low working temperature, high in sensitivity and low in detection limit.

The invention belongs to the field of metal organic framework materials, and relates to an FMOF material with high water stability, preparation of the FMOF material and application of the FMOF material in sensing detection of fleroxacin in water. The preparation method comprises the following steps: taking cadmium salt and N, N '-bis (4-carboxyl-3, 5-dimethylphenyl)-1, 4-naphthalimide (H2L) ligand as raw materials, dissolving the raw materials in an organic solvent according to a certain proportion, and synthesizing the FMOF material by adopting a solvothermal method. The preparation process is simple, and the water stability of the material is high; the synthesized FMOF material has the advantages of rapidness, high sensitivity, high selectivity and the like in the aspect of detecting fleroxacin in water.

The invention relates to a construction method and application of a label-free nanopore channel. The single-cone-shaped nanopore channel is prepared from a polyethylene terephthalate (PET) nuclear pore membrane by a track etching method, and carboxyl on the surface of the nanopore is activated by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) and is modified by dendritic polyamidoamine (PAMAM) (see the specification in detail). It is found through experiments that by combining the nanopore channels with graphene oxide, selective detection of tetracycline in water can be achieved, and other antibiotics do not interfere with the detection system. Therefore, the nanopore channel can be used for establishing a new method for detecting tetracycline in an environmental water sample.