32results about How to "Improve electrochemical response signal" patented technology

The invention discloses a silver-poly dopamine-graphene-composite-modified electrochemical sensor which is mainly characterized in that a silver-poly dopamine-graphene composite membrane is coated on the surface of a glassy carbon electrode. A preparation method of the silver-poly dopamine-graphene-composite-modified electrochemical sensor includes: adding silver-poly dopamine-graphene into dimethylformamide for uniform dispersing so that silver-poly dopamine-graphene dispersion liquid is obtained, then coating the dispersion liquid on the surface of the glassy carbon electrode, and evaporating solvent to obtain the needed sensor. A silver-poly dopamine-graphene composite is prepared only by mixing reactants and stirring at the room temperature. The preparation method is simple, mild in reaction conditions and low in cost. The prepared electrochemical sensor has the advantages of high sensitivity, low detection limit and the like, and is capable of achieving rapid sensitivity determination of guanine and adenine, simple to operate, green and environment-friendly.

The invention discloses a method for preparing a composite material of polypyrrole granules and a titanium dioxide nanotube array. The method comprises the following steps of: (1) synthesizing a titanium dioxide nanotube array and roasting to obtain an anatase type titanium dioxide nanotube array; and (2) electrochemically polymerizing the roasted titanium dioxide nanotube array as a working electrode and a platinum electrode as an auxiliary electrode for 15-120 min under the condition of controlling the voltage to be 0.8-1.0V in an aqueous solution consisting of sodium dodecyl benzene sulfonate and pyrrole monomers to obtain a finished product of the composite material of the polypyrrole granules and the titanium dioxide nanotube array. In the invention, the nano polypyrrole granules are loaded on the titanium dioxide nanotube array by utilizing a constant potential, an implementation method is simple and convenient with the characteristics of low cost and is easy for operation, and the prepared composite material has important application in many high-tech fields such as high-performance catalysts, solar batteries, photoelectrocatalysis, and the like.

The invention discloses a chemically modified electrode for sensitive detection of doxycycline as well as a preparation method and application thereof. The modified electrode is a glassy carbon electrode with high electrical activity and modified by ZnIn2S4@In2O3@MXene nanocomposite. The invention relates to the field of electroanalytical chemistry and electrochemical sensors. The ZnIn2S4@In2O3@MXene graded tubular heterojunction nanocomposite disclosed by the invention has large specific surface area and high catalytic activity and can increase the enrichment amount of doxycycline in an electrochemical detection medium and improve the measurement sensitivity while effectively accelerating electron transfer and improve the electrochemical response signal; and the composite has the advantages of high selectivity, simplicity and convenience, low price and high stability and is suitable for field detection. The chemically modified electrode prepared by the invention is already successfully applied to the accurate detection of doxycycline in animal-derived food.

The invention relates to an electrochemical immune sensor for phosphating protein. In the electrochemical immune sensor, a magnetic nanometer-antibody composition MPs-p53<15>Ab1 is used as an adsorbent to separate the phosphating protein, a carbon nanometer sphere CNS is used as a carrier, lead phosphate-apoferritin (LPA) and a phosphating protein antibody p5315Ab2 are modified on the surface of the CNS, and thus, LPA-p53<15>Ab2-CNS nanometer complexing agent is prepared for detecting signal amplification. According to the sandwich immunoassay principle, the content of the phosphating protein to be detected is in proportion to the captured LPA-p5315Ab2-CNS, and the content of lead ions encapsulated in LPA is detected according to a dissolving volt-ampere method to measure the concentration of the phosphating protein in a sample. The method has the advantages of simplicity and convenience for operation and simple and efficient separation, and the advantage that an integral immunologic reaction is finished in an epoxy (EP) tube; a large number of LPA signal molecules are introduced by taking the CAN as the carrier, and each LPA molecule contains a large number of Pb<2+>, so the sensitivity of detection is improved; and the dissolved Pb<2+> is used as a detection signal without adding an enzyme substrate, so the electrochemical immune sensor is a reagent-free sensor. In the electrochemical immune sensor for the phosphating protein, the linear concentration range of the phosphating protein phosphor-p53<15> is from 0.02 to 20 ng mL<-1>, and the detection limit is 0.01 ng mL<-1>.

The invention belongs to the technical field of detection of chloramphenicol residues in animal food, and discloses a glassy carbon electrode modified by poly L-cysteine and reduced graphene oxide loaded nano-silver and a method for detecting chloramphenicol by using the electrode. The electrode is prepared through the following method which comprises the steps: carrying out ultrasonic treatment on reduced graphene oxide loaded nano-silver until the reduced graphene oxide loaded nano-silver is uniformly dispersed to obtain a reduced graphene oxide loaded nano-silver solution; dropwise coatingthe solution on the surface of a treated bare glassy carbon electrode, performing drying, putting the obtained reduced graphene oxide loaded nano-silver modified glassy carbon electrode into an L-cysteine aqueous solution, and carrying out cyclic voltammetry scanning polymerization, so as to obtain the poly L-cysteine and reduced graphene oxide loaded nano-silver modified glassy carbon electrode.The electrode can improve a chloramphenicol response signal, improve chloramphenicol detection reliability and realize qualitative or quantitative detection of chloramphenicol residual quantity in animal food.

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 discloses a molecularly imprinted electrochemical sensor for CYR trace rapid detection. The molecularly imprinted electrochemical sensor for the CYR trace rapid detection comprises a working electrode, a reference electrode and a counter electrode; the working electrode is a glassy carbon electrode, and modified by using monodispersed SiO2@TiO2 core-shell nanoparticles firstly, and then a surface molecularly imprinted membrane is further prepared for realizing specific recognition of CYR by using a in-situ electrochemical polymerization method and sol-gel method. The molecularly imprinted electrochemical sensor has strong selectivity and high sensitivity for CYR, and is simple in sample pretreatment steps, rapid and simple in method and satisfactory in detection results of actual vegetable samples. The molecularly imprinted electrochemical sensor prepared by the invention is successfully applied to detection of CYR in cucumbers, mushrooms, Chinese chives and celery, and further good all in sensitivity, accuracy, precision and selectivity.

The invention relates to the fields of electrochemical sensors and electro-analytical chemistry and particularly discloses an electrochemical sensor for performing rapid trace detection on a preservative, namely butyl p-hydroxybenzoate, and a preparation method of the electrochemical sensor. The electrochemical sensor for performing the rapid trace detection on the preservative, namely butyl p-hydroxybenzoate, is high in measurement sensitivity, good in selectivity, simple to operate and low in cost, and a result is credible. The electrochemical sensor comprises a working electrode, a reference electrode and a counter electrode, wherein the working electrode adopts a glassy carbon electrode dropwise coated with a hollow CeO2 microsphere modified film with high electroactivity. The prepared electrochemical sensor is successfully applied to detection of butyl p-hydroxybenzoate in spiced dried bean curds, a variety of cellulose compound capsules, jam and cosmetics.

The invention provides an electrochemical sensor for detecting MicroRNA-21 and a detection system comprising the electrochemical sensor. The electrochemical detection electrode system comprises a working electrode, a reference electrode and a counter electrode, wherein the working electrode is obtained by fixing a capture probe aiming at MicroRNA-21 on the surface of a gold electrode. The MicroRNA-21 is detected by using the sensor or the detection system disclosed by the invention, the concentration of the MicroRNA-21 is in a linear relation in a range from 0.001nmol / ml to 25nmol / ml, the linear equation refers to Y=1.19999E<-5>+3.63774E<-6>X, the correlation coefficient is 0.9973, and the lowest detection limit is 0.6pmol / ml. Compared with the prior art, the sensor or the detection system is high in sensitivity, high in specificity, low in cost, easy and convenient to operate and short in detection period, is suitable for measuring the MicroRNA-21 in actual samples and is expected to become a sensor or a detection system with actual application values.

The invention discloses an electrochemical method for detecting parathion pesticides. The method comprises the following operation steps of (1) preparing a PIL / ZIF-8CPE electrode; (2) preparing a standard solution; (3) drawing a standard curve, wherein the oxidation peak current value and a parathion standard solution in the concentration range being 5.0 to 700mumg / L have a good linear relationship, and the linear equation is ip=0.1616C+4.493; in the practical parathion detection process, the parathion standard solution is replaced into a sample to be tested; the oxidation peak current value measured at -0.208+ / -0.01V is substituted into the linear equation; the content of parathion in the sample to be tested is obtained through calculation. The method is simple; the cost is low; the sensitivity is high.

The invention belongs to the technical field of medical detection and discloses a circulating tumor cell (CTC) detecting probe, a preparation method thereof and an application diagnosis sensor. According to the invention, an efficient CTC detecting probe is formed through combination of antibody and an enzyme marker carrier, so that the capture rate of target cells is increased and the electrochemistry response signal is improved at the same time to realize high-sensitivity cell detection.

The invention discloses an electrochemical method for detecting parathion pesticides. The method comprises the following operation steps of (1) preparing a PIL / ZIF-8CPE electrode; (2) preparing a standard solution; (3) drawing a standard curve, wherein the oxidation peak current value and a parathion standard solution in the concentration range being 5.0 to 700mumg / L have a good linear relationship, and the linear equation is ip=0.1616C+4.493; in the practical parathion detection process, the parathion standard solution is replaced into a sample to be tested; the oxidation peak current value measured at -0.208+ / -0.01V is substituted into the linear equation; the content of parathion in the sample to be tested is obtained through calculation. The method is simple; the cost is low; the sensitivity is high.

The invention discloses a chemically modified electrode for sensitive detection of sulfaguanidine and a preparation method and application thereof. The chemically modified electrode is a high-electroactivity AgPt@MXene nanocomposite modified glassy carbon electrode, and relates to the field of electroanalytical chemistry and electrochemical sensors. The AgPt@MXene heterojunction nanocomposite hasa large specific surface area and high catalytic activity, and is capable of enhancing the enrichment amount of the sulfaguanidine in the detection mediums, improving the sensitivity of the measurement, effectively accelerating the electron transfer and improving the electrochemical response signal. The prepared chemically modified electrode is good in selectivity, simple, low in cost and good instability, is suitable for on-site detection, and is successfully applied to the accurate detection of the sulfaguanidine in animal-derived foods.

The invention discloses a chemically modified electrode for sensitive detection of sulfamidine and its preparation method and application. The chemically modified electrode is a glassy carbon electrode modified by AgPt@MXene nanocomposites with high electroactivity, and relates to electroanalytical chemistry and electroanalysis. In the field of chemical sensors: the AgPt@MXene heterojunction nanocomposite material disclosed by the present invention has a large specific surface area and catalytic activity, can enhance the enrichment of sulfamidine in the detection medium, improve the sensitivity of the measurement, and can effectively accelerate electron transfer. Improve the electrochemical response signal; the chemically modified electrode prepared by the invention has good selectivity, is simple, cheap, and has good stability, is suitable for on-site detection, and has been successfully applied to the accurate detection of sulfamidine in animal source food.

The invention discloses a glassy carbon electrode modified by a polypeptide nanogold composite material and an antibody penicillin receptor, and a method for detecting [beta]-lactam antibiotics by using the electrode, and belongs to the field of food detection. The preparation method comprises the following steps: uniformly dispensing a C16R4-AuNPs nano composite material on the surface of a pretreated GCE electrode to generate C16R4-AuNPs / GCE, then dropwise adding a penicillin antibody on the surface of the electrode, incubating, then cleaning the surface, and washing away the uncombined antibody; dropwise adding BSA (bovine serum albumin) on the surface of the electrode, and incubating; and dropwise adding a penicillin receptor on the surface of the electrode, and incubating to obtain the glassy carbon electrode modified by the polypeptide nanogold composite material and the antibody penicillin receptor. The electrode has a relatively good detection limit and a relatively wide linear range on the [beta]-lactam antibiotics, the detection sensitivity of the [beta]-lactam antibiotics is obviously improved, and meanwhile, the electrode has good anti-interference capability and selectivity.

The invention belongs to the technical field of detection of the total amount of aflatoxin in peanuts and products thereof in food, and discloses a polypeptide-nanogold (PP-AuNPs) modified glassy carbon electrode and a method for detecting the total amount of aflatoxin in peanuts and products thereof by using the electrode. The modified material is prepared by the following steps: (1) adding a HAuCl4 mother solution into a polypeptide-containing HEPES buffer solution, and performing stirring at room temperature to obtain a PP-AuNPs composite material; (2) grinding and polishing the bare glassy carbon electrode on alumina powder, then sequentially carrying out ultrasonic treatment in absolute ethyl alcohol and ultrapure water, then performing washing with water, and placing thebare glassy carbon electrode in a potassium ferricyanide solution for cyclic voltammetry scanning; and (3) dispensing the PP-AuNPs composite material obtained in the step (1) on the surface of the bare glassy carbon electrode treated in the step (2), and performing drying at constant temperature to obtain the PP-AuNPs modified glassy carbon electrode (PP-AuNPs / GCE for short). The modification material is dispensed on the surface of an activated bare glassy carbon electrode and dried, an antigen, a confining liquid (BSA) and a to-be-detected sample are sequentially dispensed, incubation is performed, and then electrochemical signal detection is performed. According to the detection method, the response signal of the total amount of aflatoxin can be improved, the reliability of aflatoxin detection is improved, and qualitative or quantitative detection of the residual amount of aflatoxin in peanuts and products thereof is realized.

The invention discloses a preparation method of an electrochemical sensor for detecting butyl p-hydroxybenzoate, and relates to the technical field of electrochemical sensors. The preparation method comprises the steps of modification of flexible graphite, loading, dispersion, pretreatment of a glassy carbon electrode and preparation. Improved flexible graphite modified nano titanium dioxide is used as a sensor sensitive material, is simple and convenient to prepare and low in cost, and has the advantages of large specific surface area, good conductivity and high enrichment capacity, and a uniform film can be formed on the surface of the electrode by methods of simple drip coating and solvent evaporation; and the preparation method is simple and convenient to operate, special experiment conditions are not required, and the electrochemical sensor is convenient to carry and high in practicality, and cannot damage an ecological environment and operators.