568 results about "Voltammetry" patented technology

An organic EL device includes a pair of electrodes, a light emitter layer obtained by mixing a hole transporting material made of a tertiary amine compound, an electron transporting material and a light emitting additive. The tertiary amine compound constituting the hole transporting material has only one oxidation potential as measured by the cyclic voltammetry. A difference in ionization potential between the hole transporting material and electron transporting material of the light emitter layer is 0.35 eV or greater.

The invention provides a method for identifying asynchronous motor parameters offline under a stationary state. The method comprises the steps of firstly, identifying a stator resistance value of a motor by using a direct current voltammetry; and then taking a single-phase rated-frequency alternating voltage and a single-phase low-frequency alternating voltage as an excitation source respectively to perform a single-phase alternating current test, obtaining steady-state response currents of the motor through detection, and obtaining a motor stator leakage inductance, a rotor inductance, a rotor resistance and a stator-rotor mutual inductance value through calculation. According to the method, calculation is performed in strict accordance with a motor classic equivalent circuit model, the accuracy is high, additionally, the condition that a reference voltage output by a motor controller is not accordant with the actual voltage and effects of the skin effect are further considered, corresponding compensation measures are taken, and the parameter identifying accuracy is further improved.

System, method, and test strip for solid phase, electrochemical, quantitative analysis of analytes contained in biological fluid samples. Preliminary to analysis, a test sample solution can be applied to a sample collection pad associated with the solid phase test environment of the test strip. The test sample solution and a test kit reagent are thereby initially contacted, under assay conditions, within this solid phase test environment, and caused to migrate along a fluid pathway therein. Irrespective of the assay format (competitive assay, sandwich assay, etc.), a test kit reagent (e.g. labeled substance) and the analyte of interest (e.g. proteins, hormones or enzymes, small molecules, polysaccharides, antibodies, nucleic acids, drugs, toxins, viruses or virus particles, portions of a cell wall and other compounds which have specific or characteristic markers that permit their identification), either interact with one another to form a complex, or, alternatively, compete with one another for interaction with another test kit reagent, resulting in the concentration of an indicator substance within a delimited area of the solid phase. Thereafter, the delimited area of the test strip is subjected to electrochemical analysis and the results determined by monitoring an electrochemical transition in the form of an indicator, or derivative of the indicator (e.g. indicator species), by potentiostatic or potentiometric quantitative analysis (e.g. anodic stripping voltammetry). This electrochemical transition of the indicator has a characteristic electrical fingerprint that can be measured and which, when compared to a standard, can be correlated with the concentration of the analyte in the sample. This method is suitable for the determination/monitoring of therapeutic range of drugs (anti-convulsants drugs), determination of critical and potentially dangerous levels of endogenous materials which are indicative of disease states (prostate cancer), and numerous other applications presently requiring elaborate and time-consuming clinical laboratory analysis.

The invention relates to a sensor, in particular to an ion selective electrode based on a conducting polymer film and a preparation method thereof. The ion selective electrode based on the conducting polymer film aims at solving the problem that a traditional ion selective electrode with internal reference solution is difficult to miniaturize and is short in service life. The ion selective electrode comprises an insulation electrode shell, a metal platinum wire, conducting polymer, an ion selective electrode film and a filled gold contact. The metal platinum wire is fixed into the insulation electrode shell, the electrode is arranged on the metal platinum wire, one end of the metal platinum wire is connected with the filled gold contact, the other end of the metal platinum wire forms the conducting polymer on the surface of the metal platinum wire through cyclic voltammetry, and the ion selective electrode film covers the conducting polymer. The ion selective electrode based on the conducting polymer film has the advantages of being miniaturized, and long in service life.

The invention discloses a method for quickly detecting lead and cadmium by adopting scanning anodic stripping voltammetry. The method comprises the following steps: a sample to be tested is prepared; lead or cadmium standard liquid is prepared; a three-electrode system consisting of glassy carbon electrodes plated with mercury films, platinum wire counter electrodes and Ag/AgCl reference electrodes is assembled; parameters are set and the scanning anodic stripping voltammetry is adopted to respectively implement parallel determination for current values between working electrodes and reference electrodes of each standard liquid solution until the relative standard deviation of readings is not more than 5%; lead and cadmium heavy metals of the sample are measured through detecting the current values between the working electrodes and the reference electrodes; a working station automatically calculates to obtain detecting results through automatically searching peaks to determine each curve peak area. The detecting method has the advantages of high sensitivity, good accuracy, reduction of mercury pollution, high electrode stability and good reproducibility, and can be applied to the detection of the heavy metals of lead and cadmium with conventional trace and ultratrace.

The invention relates to preparation for a cadmium antimonide quantum dot immune marker and a detection method for electrochemical sandwich immune, having the signal amplification function. Through the reaction of silicon dioxide particle and reacting ATPS, an active amido group is modified on the surface of the silicon dioxide particle under room temperature. The silicon dioxide particle is then reacted with carboxyl on the surface of a quantum dot to form a silicon dioxide microsphere with the surface modified with the quantum dot. The silicon dioxide microsphere after being modified is further modified with a second antibody on the surface of the quantum dot under the actions of EDC and NHS, and a cadmium antimonide quantum dot immune marker is obtained. The detection method for the electrochemical sandwich immune utilizes anti-AFP to modify Fe3O4 magnetic nano-microsphere, thereby Si/QD/Ab2 is modified on magnetic particles, and then electrochemical determination is carried out. Because the surface of the marker is rich in the quantum dots, the amount of the quantum dot loaded in a single sandwich immune process is greatly increased, dissolving-out voltammetry detection signals of an anode are amplified, and the sensitivity of low-concentration biomolecule detection is greatly enhanced.

The invention relates to a preparation method of a composite anode of a microbial fuel cell with a carbon-base material modified by a conductive complex. The preparation method comprises purifying a multi-wall carbon nanotube; placing the purified multi-wall carbon nanotube into a 0.1 to 0.5mol/L supporting electrolyte solution, and dispersing the carbon nanotube in the solution, with 5% to 20% of carbon nanotube; adding 3,4-ethylenedioxythiophene monometers into the solution to obtain a well-dispersed 3,4-ethylenedioxythiophene/multi-wall carbon nanotube suspending solution; electrically depositing a complex on the anode surface by cyclic voltammetry; and carrying out vacuum drying, washing with deionized water, and room-temperature airing in sequence to obtain the modified anode. The method provided by the invention can reduce use amount of toxic reactants and shorten the preparation process so as to save the preparation cost. The modified anode has the advantages of peculiar surface effect, good conductivity and electrochemical activity, is remarkably improved in the maximum power density and open-circuit voltage in comparison with the unmodified anode when used in a battery, and can greatly reduce the battery internal resistance.

The invention discloses a three-electrode integrated electrochemical sensor based on a microelectrode array. The sensor comprises the bismuth film modified microelectrode array (gold working electrode), a silver/silver chloride electrode (reference electrode) and a platinum electrode (counter electrode). The three electrodes are prepared through a standard MEMS technology, and multiple discs at equal intervals are evenly distributed on the gold electrode to serve as the microelectrode array. In the electrochemical detection process, heavy metal gathering and dissolving-out reacting occur on the microelectrode array, and the surface of the microelectrode array is modified with a bismuth film in order to increase the detection type of heavy metal and expand the detection range of the heavy metal. The surface of the silver electrode is electroplated with silver chloride to form the Ag/AgCl reference electrode. The platinum electrode serves as the counter electrode and forms an access with the working electrode. Difference pulse stripping voltammetry is utilized for determining the concentration of the heavy metal, and a result shows that the sensor is high in detection sensitivity, low in detection limit and high in signal-to-noise ratio; the sensor is easy and convenient to operate, needs a small quantity of samples, can be used for rapidly detection heavy metal on site and is capable of efficiently monitoring environmental pollution in real time.

The invention relates to a preparation method of a graphite oxide phase carbon nitride modified electrode. The preparation method comprises the following steps: (1) preparing graphite oxide phase carbon nitride; and (2) preparing a graphite oxide phase carbon nitride sensor. The electrode is applied to detecting heavy metal ions. Graphite oxide phase carbon is of a three-dimensional hole structure which is large in specific surface area and contains hydrophilic groups such as hydroxyl, carboxyl, and epoxy groups. The graphite oxide phase carbon is applied to an electrochemical sensor. The heavy metal ions Cu<2+> are detected by virtue of a different pulse stripping voltammetry, and influence of factors such as enriching time, enriching potential, the pH value of a solution, and modification amount on stripping peak current can be optimized. Under an experimental condition that the enriching time is 300s, the enriching potential is -0.6V, the pH value of the solution is 4.68 and the modification amount is 12 microliters, a standard curve represents a good linear relationship, wherein the linear range is (1.60*10<-15>-6.31*10<-15>mol/L, the linear equation is ip(microA)=1.2533C(micro mol/L)+6.2232, the correlation coefficient (R) is 0.9989, and the limit of detection (S/N=3) reaches 1*10<-16>mol/l. The electrode has ultrahigh sensitivity to heavy metal ion detection.

In an arrangement for monitoring of flow within a hydrocarbon well or reservoir by means of one or more tracers which are placed at subterranean locations such that they may be present in flow produced from the well, the analysis of the flow produced from the well is carried out using an electrochemical method, preferably voltammetry, to detect tracer chosen to undergo a detectable electrochemical reaction. The tracer may be provided as nanoparticles in the well fluid.

The invention discloses a method for detecting of the heavy metal lead content of the teas, the major steps include that: the tea samples to be measured are carried out the microwave digestion in the presence of H2O2 and nitric acid with a certain proportion, 0.1mol/L of NH4Cl solution dilution digestion liquid is used, the mercury plating liquid is added till the concentration of mercury ions in the solution achieves 4 multiplied by 10 to <4>mol/L, and the solution is detected by combining a screen-printing electrode with a data collection and processing system. The invention applies the electrochemical analysis method, adopts the three-electrode-to-one screen-printing electrode, uses the method of mercury plating in situ and takes the square wave stripping voltammetry as the tection method, so the invention has the advantages of simple, rapid, sensitive, accurate and economic.

The invention relates to a multiparameter water quality heavy metal automatic online monitor based on the anodic stripping voltammetry. The monitor is characterized in that: the monitor comprises an electrochemical detection device, a control system, and a liquid charging device, a reaction device and a liquid discharging device which are respectively connected with the control system; the liquid charging device and the liquid discharging device, which jointly comprise peristaltic pumps, a precise syringe pump and six connection solenoid valves, are connected with the reaction device through pipelines to send a solution to the reaction device or discharge the solution from the reaction device; and the reaction device which is formed by inserted electrodes and an electrolytic cell with a stir bar provided therein is connected with the electrochemical detection device and can timely obtain effective data. By adopting the anodic stripping voltammetry in the invention, the simultaneous determination of multiple parameters can be realized, the reagent consumption is less, the apparatus is simple, the determination lower limit can be reduced by 2-3 orders of magnitude, and the chroma and the turbidity have no influences on the monitor, so the monitor can be used for the analysis of surface water and purified water.

The invention discloses an electrochemical sensor for detecting heavy metals. The sensor comprises a glassy carbon electrode serving as a working electrode in a three-electrode system, wherein ordered mesoporous carbon is modified on the surface of the detection end of the glassy carbon electrode; polyaniline and 2-mercaptoethanesulfonate are deposited on the ordered mesoporous carbon. A preparation method comprises the following steps of dispersing the mesoporous carbon into an organic solvent to obtain a mixture, then dispensing the mixture onto the surface of the glassy carbon electrode, and depositing polyaniline and 2-mercaptoethanesulfonate on the surface by an electrochemical cyclic voltammetry to prepare the electrochemical sensor. An application step comprises the following steps: putting the reaction end of the glassy carbon electrode of the electrochemical sensor into a solution to be measured, then connecting to an electrolytic basin of the three-electrode system, and implementing the detection on the concentration of heavy metal ions by a differential pulse anodic stripping voltammetry. The electrochemical sensor for detecting the heavy metals is low in cost, easy to manufacture, high in sensitivity, low in detection lower limit, high in interference resistance, easy to apply and operate and safe and pollution-free to the environment.

The invention relates to a chiral sensor based on chitosan/cyclodextrin dinuclear copper and a manufacturing method of the chiral sensor. Chitosan (CS) constant potentials are deposited on the surface of a glassy carbon electrode (GCE), a modified electrode is subjected to alkali treatment, and cyclodextrin dinuclear copper (Cu2-beta-CD) is self-assembled to obtain a novel sensor of CS/Cu2-beta-CD, and tryptophan enantiomers are selectively identified by a DPV (differential pule voltammetry) method. The manufacturing method includes steps of preparing Cu2-beta-CD, preparing modified GCE of alkali-treatment CS and CS/Cu2-beta-CD electrode, and electrochemically identifying L/D-Trp. The chiral sensor has the advantages that the CS/Cu2-beta-CD modified electrode is simple to operate, time saving and free of pollution. The result indicates that the glassy carbon electrode modified by the CS/Cu2-beta-CD has efficient identification effect for tryptophan enantiomer, and oxidation peak current ratio of L/D-tryptophan (L/D-Trp) is averagely up to 7.26.

The invention relates to a grapheme-modified platinum electrode. The grapheme-modified platinum electrode is formed by oxidizing a platinum electrode on a silicon chip to generate a carbon dioxide layer for serving as a substrate, evaporating a metal platinum electrode on the carbon dioxide substrate and growing grapheme on the platinum electrode. A stripping voltammetry method is adopted, the grapheme-modified platinum electrode manufactured with an MEMS (Micro-electromechanical System) is taken as a working electrode, an Ag/AgCl electrode is taken as a reference ratio electrode, a platinum wire electrode is taken as a counter electrode, parameter selection of post-treatment, enriching time, potential setting, stripping voltammetry are performed, the heavy metal extreme value is 0.05 mg/L according to detection, and a provided G/Pt electrode has remarkably higher detection sensitivity than a naked Pt electrode.

The invention belongs to the technical field of lithium metal batteries, and particularly relates to a method for preparing an anode porous copper current collector used for a lithium metal battery. The method at least comprises a first step of cleaning the surface of a Cu-X alloy sheet with a solvent to remove impurities on the surface of the Cu-X alloy sheet; a second step of preparing an acid solution; and a third step of preparing the porous copper current collector by scanning different numbers of turns from -1 V to different cut-off voltages by adopting linear scanning cyclic voltammetry in an electrochemical workstation, with a three-electrode system being utilized, platinum or nickel being adopted as a counter electrode, a saturated calomel electrode being adopted as a reference electrode, the Cu-X alloy sheet being adopted as a working electrode, and the acid solution prepared in the second step being adopted as an electrolyte. Compared with the prior art, the porous copper current collector having different pore diameters are etched through an electrochemical process by utilizing the Cu-X alloy sheet as a substrate and adopting acids having different concentrations as media. The current collector is used as a lithium metal battery anode current collector, and has functions of providing deposition space for lithium metal and limiting growth of lithium dendrites.

The invention discloses a label-free electrochemical immunosensor for melamine content determination, and a preparation method and application thereof. The immunosensor comprises a substrate electrode, wherein the surface of the substrate electrode is modified by a graphene-melamine-chitosan composite, and nonspecific active sites are sealed by bovine serum proteins. The method for preparing the electrochemical immunosensor is implemented by fixing melamine antigens on the surface of a glass carbon electrode with graphene/chitosan composite materials. Based on an immunoreactive competition mode, the electrochemical immunosensor monitors immune reaction through cyclic voltammetry and differential pulse voltammetry by taking K3Fe(CN)6 as a probe,, and can be used for melamine content detection. The immunosensor disclosed by the invention is high in sensitivity and specificity, simple in detection method and wide in application range; the limit of detection can reach 0.2 ng/ml, and the linear range is 5-1500 ng/ml; and the immunosensor has the characteristics of high speed, high efficiency, high sensitivity, good specificity, simple operation, low cost and the like.

Refinery feedstocks can be characterized based on any of: dissociation of acids in the crude, breakup of naphthenic acid molecular associations, and/or dissociation of sulfur compounds in the feedstocks. The characterization is performed as a function of temperature via any of electrical resistivity measurement, vibrational spectroscopic analysis, voltammetry, electrochemical impedance spectroscopy (EIS) and combinations thereof The method can be practiced in any of refinery, terminal, and laboratories. It can be used in conjunction with models and hardware to optimize the usage of refinery feedstocks in the blending and valuation of the feedstocks. In one embodiment, the characterization of refinery feedstocks is via the use of EIS.

A method for the quantitative determination of an ion in a fluid which comprises subjecting the fluid to voltammetry using a sensing electrode which comprises an electrically conducting support having a surface which is coated with a support matrix, the support matrix containing an electroactive species capable of being oxidised or reduced to form a charged species, and an ionophore.

The invention provides a preparation method of a porous metal nickel and a nickel-based porous film super-capacitor electrode material on the surface of the porous metal nickel. The method comprises the steps of taking a metal nickel base as an anode, and performing step anodization on the anode metal nickel base by a step anodization method to form the porous nickel; and then dissolving the porous nickel into alkali liquor, processing by a circulating voltammetry or a constant current charging and discharging method, so as to form the porous metal nickel and the nickel-based porous film super-capacitor electrode material on the surface of the porous metal nickel. According to the method provided by the invention, the electric vibration is generated on the anode by a step anodization method, and performing pore-forming on the metal nickel. The method can be realized simply by two-pole equipment, and a prepared nickel-based oxide thin film is very high in rate capability, therefore the specific capacitance can reach 0.564F/cm2 after circulating for 100,000 times under the condition of large current of 40Ma/cm2; furthermore, the specific capacitance can reach 0.6F/cm2 under the condition of large current of 100mA/cm2, and the circulating life is not lower than 10,000 times.

The invention provides a nano photoelectrochemical sensor for detecting dopamine with high sensitivity. The dopamine can be deposited to the surface of an electrode by using a chemical oxidation or electrochemical oxidation method, so as to form a polymer film, so that the photocurrent intensity of a quantum dot is reduced. Compared with a most common method for measuring the dopamine by using electrochemical cyclic voltammetry, the selectivity in detection of dopamine is improved, the measurement is not interfered by common coexisting substance ascorbic acid and uric acid in relatively high concentration, and the nano photoelectrochemical sensor is the first application of a photoelectrochemical method in detection of dopamine. With the adoption of the nano photoelectrochemical sensor, the dopamine detection with high-sensitivity is realized, the linear range is 2*10<-10>mol/L to 2*10<-5>mol/L, and the detection limit is 1*10<-10>mol/L. With the adoption of the method, the detection result of the dopamine in human urine is satisfactory, so that the method has the possibility of being applied to detection of the dopamine in human urine.

The invention discloses a special electrode for in-vivo voltammetry analysis and a preparation method thereof. The preparation method of the special electrode comprises the following steps: 1) preparing carbon fiber coated with a carbon nanomaterial on surface; 2) preparing a carbon fiber microelectrode; 3) soaking the carbon fiber electrode prepared by the step 2) in solution for ultrasonic washing; and 4) subjecting the carbon fiber electrode prepared by the step 3) to electrochemical pretreatment to obtain the special electrode. Meanwhile, an electrochemical detection device for in vitro correction or in vivo real-time physiological activator monitoring is prepared by using the special electrode. The electrochemical detection device comprises the special electrode for physiological activator monitoring of the invention, a reference electrode and an auxiliary electrode. The electrochemical detection device prepared by using the special electrode of the invention can meet the requirements for the in-vivo voltammetry analysis of physiological activators and has a promising application prospect in researches in fields of neurophysiology, clinical medicine and the like.

The invention relates to the field of electrochemical sensors, and particularly relates to an alloy electrode electrochemical sensor for quickly detecting trace heavy metals. The electrochemical sensor specifically comprises an alloy working electrode, a reference electrode and an auxiliary electrode, wherein the working electrode, the reference electrode and the auxiliary electrode are respectively connected to a control potential rectifier by leads; and the working electrode is made of tin-bismuth alloy. The detection method is implemented by inserting the three electrodes into a sample to be detected, then detecting the concentration of heavy metal ions in the sample to be detected through stripping voltammetry. The electrochemical sensor provided by the invention is simple in process, low in cost, high in selectivity and sensitivity and good in stability, and can be widely applied to the quick field detection and daily monitoring of heavy metal ions in fresh water, sea water, food and body fluids.

The invention provides a method for identifying stator resistance parameters, comprising the following steps: adopting the two point method on the basis of the ordinary direct current (DC) voltammetry to set two winding current target values; and injecting DC at twice and respectively recording the voltage value and current value of the DC and obtaining the stator resistance value by differentiation and integration. The voltage drop of an insulated gate bipolar translator (IGBT) and the voltage drop of a freewheel diode are cancelled out in computation, so that the identification precision is improved, dependency on devices is eliminated and the adaptability is very good.

The invention provides a method for measuring parameters of a direct-current brushless motor, which can simply measure phase resistance of the direct-current brushless motor by using a voltammetry, and can respectively calculate rotational inertia and friction torque coefficient of a system, namely rotational inertia and friction torque coefficient of the direct-current brushless motor to be detected by utilizing the simplicity and operability in the direct-current motor parameter measurement, when a direct-current motor drags the direct-current brushless motor to be detected and when the direct-current motor is individually operated. A direct-current motor 2 with suitable power, which is used as a dragged motor, is connected with a motor to be detected 4 through a torque transducer 3, so as to supply power to the direct-current brushless motor to be detected 4; the direct-current brushless motor to be detected 4 drags the direct-current motor 2; and the dragged direct-current motor is connected in series with a slide rheostat with a reasonable resistance value in a three-phase manner. The direct-current brushless motor 4 rotates at a constant rotation speed; the resistance value of the slide rheostat can be adjusted; the rotation speed is recorded, and a read number of the torque is touched; and a reasonable rotation speed-torque curve of the motor to be detected 4 can be obtained after the operation is carried out for multiple times within a reasonable rotation speed and torque range.