60results about How to "Enhanced electrochemical signal" patented technology

The invention relates to a preparation method of a prostate tumor marker immunosensor. The preparation method comprises the following steps: (1) dissolving silver-hybridized NH2-MCM-48 into a phosphate buffered solution, uniformly dispersing in an ultrasonic mode, further adding a prostate specific antigen second antibody, oscillating at the temperature of 4 DEG C, centrifuging to remove the supernate to obtain a second antibody marker Ag@NH2-MCM-48/Ab2; (2) firstly, modifying the surface of a glassy carbon electrode as a working electrode by using an amino graphene-ferrocenecarboxaldehyde composite material solution, subsequently modifying by using glutaraldehyde, further modifying by using a prostate specific antigen-anti-solution, dropping a bovine serum albumin solution, continuously modifying prostate specific antigen, and finally modifying Ag@NH2-MCM-48/Ab1 so as to obtain the prostate tumor marker immunosensor. The immunosensor prepared by using the preparation method is applied to measurement on the prostate specific antigen, and is high in sensitivity and good in specificity.

The invention belongs to the fields of preparation method and application of microelectrodes, and provides a nano flower-shaped ultramicro gold electrode and a preparation method and an application thereof. Micro carbon fibers and copper wires are adhered by a graphite conductive adhesive and then extend into a glass capillary tube with an end part stretched, and flame etching is performed to obtain a nanoscale diameter; the surface is subjected to electrochemical deposition with an electrophoretic paint, and heating and baking treatment is performed; in an acidic chloroauric acid solution, the nano flower-shaped ultramicro gold electrode is obtained by electrochemical deposition of gold. The surface of the prepared electrode is assembled with biological molecules marked with an electrochemical active substance, a receptor of the surface of a target molecule can be specifically recognized, and the target molecule is detected by an electrochemical method. The electrode can be applied in the research fields of biological sensors, biological molecular detection and the like. The preparation method has the advantages of simpliness, low cost, small size and easy operation; and the surface of the prepared gold electrode is clean, the specific surface area of the ultramicro electrode is increased, and an electrochemical signal is enhanced.

A method for detecting ultratrace DNA by electrochemical quartz crystal microbalance and double amplifying technique includes such steps as plating a thin Au or Ag film or quartz crystal, selectivelyadsorbing DNA by quartz crystal oscillator, molecular hybridizing of DNA to obtain dual-chain DNa, amplifying the detected signals in mass and electrochemical areas by the nano microbead marked by chemical or biologic reagent which can selectively act on the dual chains of DNA and has electrochemical activity, and measuring the mass signal and electrochemical signal. Its advantages are high selectivity and high sensitivity.

The invention discloses a method for preparation of a BP (black phosphorene) modified electrode and detection of rutin. The method comprises specific steps as follows: (1), poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) is taken as a protective agent and mixed with BP, and a BP-PEDOT:PSS composite material is prepared; (2), the BP-PEDOT:PSS composite material prepared in the step (1) is applied to the surface of a glassy carbon electrode (GCE) through coating and is air-dried, and the modified electrode BP-PEDOT:PSS/GCE is obtained; (3), electrochemical behaviors of rutin are researched by utilizing BP-PEDOT:PSS/GCE as a working electrode, and electrochemical parameters of related electro-catalytic reactions are calculated; (4), an electrochemical sensitivity detection method of rutin is established with differential pulse voltammetry, linear ranges are 0.02-15.0 mu mol/L and 15.0-80.0 mu mol/L, and limit of detection is 0.007 mu mol/L (3sigma). The modified electrode is successfully applied to determination of rutin tablet samples.

The invention discloses a P-rGO-C60 nanocomposite material and a P-rGO-C60-Pt@Au nanocomposite material, and also discloses an electrochemical DNA aptamer sensor for SDM detection, wherein the electrochemical DNA aptamer sensor is prepared by the following method: 1) treating an SDM aptamer by using a TCEP solution for standby application; 2) polishing a glassy carbon electrode into a mirror surface, processing the electrode, and drying for standby application; 3) electrochemically cleaning the electrode, swashing with water, and drying; 4) dropwise adding 6-10 [mu]L of P-rGO-C60 solution intothe surface of the glassy carbon electrode, drying, dropwise adding a GOD solution to the electrode; 5) dropwise adding the P-rGO-C60-Pt@Au solution to the electrode surface, and drying at room temperature; 6) taking an SDM binding aptamer, dropwise adding on the electrode, and incubating at room temperature; and 7) immersing the electrode in the GOD solution, and thus obtaining the product. A method for detecting the SDM by using the sensor is also disclosed.

The invention provides a liquid phase micro-extraction device for complex matrix sample on-line pretreatment of a capillary electrophoresis-ampere detector as well as a usage method thereof, a liquid phase micro-pumping device of the device is fixed on a fixed mount, the lower end of the liquid phase micro-pumping device is nested with a section of U-shaped hollow fiber pipe, and a capillary sample inlet end and an electrode are inserted into the other end of the hollow fiber pipe, the U-shaped hollow fiber pipe is positioned in a sample container, and a stirring device is also arranged on the sample container; and the liquid phase micro-extraction in the complex matrix sample pretreatment can be implemented according to the device of the invention. The invention has a complex matrix sample liquid phase micro-extraction pretreatment device, a capillary electrophoresis device and an ampere detector connected together to form an integral device, the range of detected substances is extended, and the sensitivity, reproducibility, stability and reliability for separating capillary electrophoresis are improved; and the device has advantages of small volume, simple structure, simple operating method, low cost, good reproducibility of the method, and convenient sample analysis after pretreatment.

The invention discloses a novel carbon nano tube electrochemical sensing interface and a preparation method thereof. The novel carbon nano tube electrochemical sensing interface is characterized in that based on a novel functional carbon nano tube static compound monomolecular layer and a modified electrode electrochemical sensing interface analysis system of a polymer film, and through the use of surface negative charge activity of the anion conducting polymer film and the adoption of layered electrostatic self-assembly, a novel poly sulfanilic acid/quaternary ammonium functional carbon nano tube/monomolecular layer sulfanilic acid nano-composite film modified electrode sensing interface is prepared. Through the electrostatic self-assembly of the poly sulfanilic acid/quaternary ammonium cation functional carbon nano tube/monomolecular layer sulfanilic acid nano-composite film electrode sensing interface, the whole preparation process is simple and time-saving, the condition is controllable, the prepared sensing interface is good in stability and repeatability, the repeatability of the preparation process of the sensing interface is high, and the problem that the stability and the repeatability of an electrochemical sensor are poor in practical application is solved to a great degree.

The present invention discloses a temperature-controllable electrochemical Hg<2+> sensor based on exonuclease (Exo III) target circulating signal amplification, and a preparation method thereof. The sensor comprises a gold plate thermal electrode, a signal probe P1, an auxiliary probe P2 and exonuclease III, the T-T mismatching structure capable of identifying Hg<2+> can be produced through the complementation of P2 and P1, the T-T mismatching structure and Hg<2+> for a double-stranded structure having a T-Hg<2+>-T structure and having a 3' blunt end, the exonuclease III is induced to digest the P1, the amount of the P1 on the surface of the electrode is decreased so as to decrease the Fc chemical signal, and the decreasing degree of the Fc chemical signal on the electrode surface and the Hg<2+> concentration form linear relationship, such that the high sensitivity detection on the Hg<2+> can be achieved.

The invention discloses a modified silk-screen printing electrode and an application thereof. Printing raw materials of an electrode carbon layer comprise carbon paste, a carbon-based nano material and an oxalic acid, the mass fraction of the carbon-based nano material is 0.3-0.5%, the mass fraction of the oxalic acid is 1-1.6%, and the balance is the carbon paste; and gold nanoparticles are deposited on the surface of a working electrode of the electrode. When the modified screen-printed electrode is used for detecting a content of trivalent arsenic ions, an electrochemical signal can be effectively improved, and the enrichment capacity of the trivalent arsenic ions on the surface of the electrode can be increased; and during use, the detection cost is low, the sensitivity is high, dependence on large instruments and professional operators is avoided, and the application range is wide.

The invention provides a construction method and application of a specific electrochemical sensor for HER2 detection, and belongs to the technical field of electrochemistry. On the main basis of enhancement of an electrochemical oxidation peak of Ru0 in an AuRu nano material under excitation of light, the electrochemical oxidation peak of Ru0 in AuRu NPs serves as a detection signal, a magnetic electrochemical sensor is designed, and the electrochemical sensor for detecting HER2 is constructed based on the phenomenon; and the specific electrochemical sensor is used for detecting a human epidermal growth factor receptor 2(HER2). The construction method for HER2 detection has the advantages of high accuracy, easy operation and the like.

The invention provides a making method of a molecularly imprinted electrochemical sensing electrode. The method comprises the following steps: self-assembling photo-crosslinkable acrylate-co-styrene random copolymer with propylene chorohydrin as a template molecule through combining macromolecular self-assembling, molecular imprinting and electrophoretic deposition technologies to obtain propylene chorohydrin coated imprinted micelles, depositing through a controlled potential electrolysis technology to form a film on the surface of a gold electrode, carrying out ultraviolet radiation crosslinking on the film under the action of a photoinitiator in order to fix combination sites between propylene chorohydrin and the polymer micelles, and eluting to remove propylene chorohydrin in order to obtain the molecularly imprinted sensing electrode. The sensing electrode can be used to determine the content of propylene chorohydrin, and has good selective identity.

The invention relates to a micro-electrolytic tank for detecting formaldehyde and a preparation method thereof. The micro-electrolytic tank is of a four-layer structure, the upper layer and the lowerlayer of the micro-electrolytic tank are acrylic plates, the two middle layers are a PDMA tank body and ITO glass respectively, a counter electrode inserting hole is formed in one side of the PDMA tank body, a reference electrode inserting hole is formed in the other side of the PDMA tank body, a storage hole channel for liquid to be measured is formed in the bottom of the PDMA tank body, and workelectrode ITO glass is fixed to the acrylic plate at the lower layer. According to the micro-electrolytic tank disclosed by the invention, the PDMS is utilized as an electrolyte solution carrier, theITO glass work electrode can effectively improve formaldehyde detection flexibility, effects of oxygen in air to electrochemical detection are reduced, and experiment accuracy is improved; by means of utilizing the acrylic plates as an external structure of the electrolytic tank, light transmission and impact resistance are effectively improved; meanwhile, cost of the electrolytic tank is reduced.

The invention belongs to the technical field of preparation of electrochemical sensors, and specifically discloses an electrochemical sensor with self-cleaning ability. The electrochemical sensor comprises an electrode core and a novel composite material based on MTOF (M refers to a doped metal element), and the composite material is attached to the surface of the electrode core. The preparation method of the sensor is simple, time-saving, low in cost and environmentally friendly. In particular, the residue of polymers and detected substance contained in the sensor and attached to the surfaceof the electrode core after detection can be oxidized under ultraviolet light and visible light conditions, thereby realizing the regeneration and self-cleaning effects of electrochemical sensor undervisible light. An electrochemical sensing platform regenerated under visible light not only reduces the tedious process of electrode polishing and modification, but also saves the cost of modifying materials, and the descaling regeneration of the electrode prolongs the service life of the electrode. The sensor is applied to the simultaneous detection of environmental pollutants, that is, hydroquinone and catechol, the operation is simple and convenient, the selectivity is good, the sensitivity is high, and the detection limit is low.

The invention relates to a construction method for an electrochemical sensor used for DNA single chain and protein molecule detection. The construction method achieves a signal enhanced effect of DNA single chain detection by introducing a unique additional DNA probe on the basis of a design of a conventional DNA electrochemical sensor, and can be further applied to the protein electrochemical sensor based on a nucleic acid aptamer. The construction method overcomes the intrinsic disadvantages of poor detection sensitivity, tedious pretreatment processes and high concentration for detection limit in a conventional electrochemical sensor used for the DNA single chain and protein molecule detection, and has very good popularized value in the field of the DNA electrochemical sensor.

The invention discloses a method for detecting miRNA-21 through carboxylated graphene oxide modified electrodes. The method includes the steps that 1, an miRNA-21 aptamer solution is dropwise added tothe surface of a gold electrode, then the gold electrode is flushed and blow-dried, a mercaptoethanol solution is dropwise added, then the gold electrode is flushed and blow-dried, a reaction solution is dropwise added, then the gold electrode is flushed and blow-dried, the gold electrode is immersed in a carboxylated graphene oxide compound saturated solution and then flushed and blow-dried, methylene blue is dropwise added, then the gold electrode is flushed and blow-dried to obtain a modified electrode, ferrocene and diphenylalanine are dissolved in ethyl alcohol, carboxylated graphene oxide is added for ultrasonic treatment, and filtrate is dried to obtain a carboxylated graphene oxide compound; 2, a plurality of modified electrodes are prepared, an impedance value corresponding to each concentration is detected, and the linear relation between difference values of the impedance values and the concentrations is obtained through calculation; and 3, the modified electrode for detecting a to-be-detected sample liquid is prepared, the impedance value of the to-be-detected sample liquid is detected, and the concentration of miRNA-21 in the to-be-detected sample liquid is obtained through calculation according to the linear relation. The method has the beneficial effect of electrochemical signals of the gold electrode are enhanced.

The invention discloses a method for electrochemically detecting C-reactive protein based on an Fc-ECG/MEL/AuNPs/SPE modified electrode, and a new electrochemical sensor Fc-ECG/MEL/AuNPs/SPE is manufactured by adopting an electrodeposition technology and an electrostatic adsorption effect and is used for detecting the C-reactive protein. An SPE is taken as a substrate, ferrocenyl formylglutation (Fc[CO-Glu-Cys-Gly-OH], Fc-ECG) is used as an electrochemical probe and a recognition element, and has a specific recognition effect on CRP, and by means of the synergistic effect of melamine and goldnanomaterials, electrochemical signals are doubly enhanced to construct the sensor, and the CRP is detected by using a DPV method. The method is simple to operate, time-saving, low in cost and relatively low in detection limit.

The invention provides a target micro RNA induced-based branched DNA nanostructure and develops a simple and ultra-sensitive micro RNA detection method based on a target micro RNA induced branched DNAnanostructure. Short DNA single-stranded tails on the two sides of the double-stranded body can use hairpin DNA4 and hairpin DNA5 to start second-stage HCR amplification; a plurality of long double-stranded bodies are generated on the two sides of the formed long double-helix DNA, so that the formed branched chain DNA nano structure can carry a large amount of methyl blue, an electrochemical signal can be effectively enhanced, and a low detection limit is realized. More importantly, the strategy provides simple operation, good reliability and ultrahigh sensitivity. The method has been successfully applied to human serum samples, and shows satisfactory results and hopeful future. Importantly, the one-stop method can greatly reduce operation steps and avoid system errors caused by a plurality of operation steps.

The inventor provides a Na < + > doped g-C3N4 composite material, a chemical sensor as well as a preparation method and application of the same. The preparation method comprises the following steps: adding g-c3N4 powder into deionized water, carrying out ultrasonic treatment for 50-70 min, and obtaining a first turbid liquid; adding a NaOH solution into the first turbid liquid, and continuously stirring for 22-25 hours at room temperature, thus obtaining a second turbid liquid; carrying out solid-liquid separation on the second turbid liquid, washing precipitate with the deionized water, and drying the precipitate to obtain Na < + > doped g- C3N4 powder. In the invention, the N<+> doped g-C3N4 electrochemical sensor is formed; under the optimal experiment condition, the range of the detectable phenol concentration of the electrochemical sensor is 1-110 [mu] M, the lowest detection limit concentration is 0.03 [mu] M (S/N = 3), and the sensitivity is 1.029 [mu] A [mu] M <-1>.

The invention discloses a porous carbon modified glassy carbon electrode, which is prepared by the steps of pyrolyzing sodium alginate under the protection of nitrogen, cooling a carbon material obtained by pyrolysis to room temperature, adding the carbon material into hydrochloric acid with the concentration of 1-5mol/L, soaking and stirring for 20-60 minutes, washing with distilled water to be neutral, and drying to obtain porous carbon; dispersing porous carbon into N,N-dimethylformamide, and carrying out uniform ultrasonic dispersion to obtain a porous carbon dispersion liquid; and polishing a glassy carbon electrode with Al2O3 until the mirror surface is smooth, then sequentially carrying out ultrasonic cleaning with ethanol and secondary distilled water, washing with the secondary distilled water, blow-drying, dropwise adding the porous carbon dispersion liquid, and drying to obtain the porous carbon modified glassy carbon electrode. A three-electrode system composed of the porous carbon modified glassy carbon electrode can distinguish oxidation peaks of catechol, hydroquinone and resorcinol, significantly enhances electrochemical signals of three target objects, improves thedetection sensitivity, and can be used for determination of actual environmental water samples.