159 results about "Screen printed electrode" patented technology

The invention relates to the technical field of solar cells, and particularly discloses a TBC solar cell structure and a preparation method thereof, and the preparation method comprises the steps of double-sided polishing, deposition and diffusion, laser treatment, etching treatment, acid pickling and texturing, deposition passivation and antireflection film, screen printing of an electrode, sintering and the like on a silicon wafer. Wherein the laser processing comprises at least one of a BSG layer process of a non-metal electrode area of a laser scanning P area and a PSG layer process of a non-metal electrode area of a laser scanning N area. According to the TBC solar cell, the secondary process is carried out on the non-metal electrode area on the back face of the cell piece through the laser, effective thinning of the poly layer of the non-metal electrode area of the TBC solar cell is achieved, the problems of optical parasitic absorption and current loss caused by the fact that the poly layer is too thick in the prior art are solved, and the conversion efficiency and the overall performance of the cell are improved.

The invention discloses an electrochemical sensor constructed based on a composite material and a preparation method and application thereof.The electrochemical sensor comprises a screen-printed electrode, the surface of the reaction end of a working electrode of the screen-printed electrode is loaded with a zirconium-based metal organic framework composite material, the composite material comprises UiO-66, and the surface of the composite material is modified with a polydopamine coating. The preparation method comprises the following steps: preparing the zirconium-based metal organic framework composite material and fixing the composite material on the working electrode of the screen-printed electrode. According to the invention, the zirconium-based metal organic framework composite material with many adsorption sites, good dispersibility, good conductivity and good hydrophilicity is used as a functional material, so that the sensor has the advantages of simple operation, low cost, rapid response, strong anti-interference capability, wide detection linear range, high detection sensitivity, long service life and the like, and can be widely used for detecting Mn < 2 + >, Mn < 2 + >, Mn < 2 + >, Mn < 2 + > and Mn < 2 + > in a water body. The method can realize rapid and accurate detection of Mn < 2 + > in a water body, and is high in use value and good in application prospect.

The invention discloses a wearable sweat glucose detection system based on multi-shell metal organic framework encapsulated enzyme and a preparation method of the wearable sweat glucose detection system. The detection system comprises a sweat collection and sensing module, an electrochemical detection module and an iontophoresis module, the sweat collecting and sensing module comprises a micro-fluidic channel and a screen-printed electrode; the micro-fluidic channel is used for collecting sweat; the screen-printed electrode comprises a working electrode for detecting glucose, a counter electrode and a reference electrode to form a three-electrode system; wherein the working electrode for detecting the glucose is provided with a functional layer, and the functional layer is modified by multi-shell metal organic framework layered encapsulation enzyme for detecting the glucose and chitosan for fixing the multi-shell metal organic framework layered encapsulation enzyme; the electrochemical detection module is used for obtaining electrochemical sensing detection data; and the iontophoresis module is used for outputting an adjustable constant current source to enable iontophoresis to stimulate skin to sweat. The portable long-time continuous detection of sweat glucose can be realized, and the detection method is rapid and convenient.

The invention discloses a method for detecting cadmium ions and lead ions in a water body by utilizing a screen-printed electrode electrochemical sensor, which comprises the following steps of: constructing the screen-printed electrode electrochemical sensor by taking a screen-printed electrode of which the surface of a reaction end is modified with a ZIF-8 / MWCNT nano composite material as a working electrode; the method comprises the following steps: detecting the peak current change of a to-be-detected cadmium / lead ion solution by using a screen-printed electrode electrochemical sensor, and calculating the concentrations of cadmium ions and lead ions in the to-be-detected cadmium / lead ion solution by using a linear regression equation of the cadmium ion concentration, the lead ion concentration and the peak current change. The method provided by the invention has the advantages of simple operation, low cost, high detection efficiency, high detection accuracy and the like, can realize on-site detection of cadmium ions and lead ions in a water body, and has the advantages of convenient operation, high accuracy, strong anti-interference capability to interference factors, and good application prospect. The method is of great significance to efficient detection of heavy metal cadmium ions and lead ions in the water environment.

A gene chip sensor for single nucleotide polymorphism detection and its application belong to the field of biosensor detection technology. In order to solve the technical problems of low specificity and accuracy, long processing time and high cost in the existing single nucleotide polymorphism detection methods, the present invention provides a gene chip sensor for single nucleotide polymorphism detection, wherein the gene chip sensor comprises WT wild-type and SNP mutant nucleotide sequences, LSL probe, and CRISPR / Cas 12a system. LSL probe is used as a recognition intermediate to activate the CRISPR / Cas12a system, iron-cobalt nanomaterials are used to provide a stable signal source for sample detection, and screen-printed electrodes are combined with electrochemical sensors; the application of CRISPR / Cas12a and nanomaterial technology in molecular breeding is expanded, and technical support is provided for economical and efficient SNP detection.

The invention relates to an expanded gate type field effect transistor sensing array and a preparation method and application thereof.The expanded gate type field effect transistor sensing array comprises a silk-screen printing electrode array and a metal oxide semiconductor field effect transistor, the silk-screen printing electrode array comprises a silver electrode and a carbon electrode, and the metal oxide semiconductor field effect transistor comprises a gate, a source and a drain. The carbon electrode is used as a detection probe after being modified by a gold / metal organic framework composite nano material and a detection probe based on a double-recognition strategy, and the carbon electrode is connected with the grid electrode through a wire to obtain the expanded grid type field effect transistor sensing array. Compared with the prior art, the novel extended gate type field effect transistor sensor for rapidly and sensitively detecting antibiotics is simple in structure, low in cost, high in stability and reusable. The double-recognition strategy probe based on combination of the aptamer and the molecularly imprinted polymer is prepared, the detection sensitivity and selectivity are improved, the synthesis method is simple, and experiment conditions are mild.

The invention discloses a gene chip sensor for single nucleotide polymorphism detection and application thereof, and belongs to the technical field of biosensing detection. In order to solve the technical problems of low specificity and accuracy, long processing time and high cost of a single nucleotide polymorphism detection method in the prior art, the invention provides a gene chip sensor for single nucleotide polymorphism detection, and the gene chip sensor comprises WT wild type and SNP mutant nucleotide sequences, an LSL probe and a CRISPR / Cas 12a system. An LSL probe is used as a recognition intermediate to activate a CRISPR / Cas12a system, an iron-cobalt nano material is used to provide a stable signal source for sample detection, and a screen-printed electrode is combined with electrochemical sensing; the application of CRISPR / Cas12a and nanomaterial technology in molecular breeding is expanded, and technical support is provided for economic and effective SNP detection.

The invention provides construction of an electrochemical biosensor based on a fucoidin hydrogel microneedle and application of the electrochemical biosensor in online monitoring of uric acid, and relates to the technical field of biosensors. According to the micro-needle, Gantrez S-97 and PEG are subjected to copolymerization crosslinking to form a hydrogel main body, fucoidin is introduced for blending modification, a three-dimensional network structure is constructed by utilizing a high-temperature esterification reaction for regulating and controlling pH, and the super-expansion hydrogel micro-needle with high swelling property and good biocompatibility is formed. The microneedle can rapidly collect a skin interstitial fluid sample, and then through a screen printing electrode (SPE) platform, carboxylated MWCNTs are used for modifying an electrode and immobilizing uricase to construct an enzyme sensor. Hydrogen peroxide generated by catalyzing uric acid on the surface of the electrode participates in electrochemical reaction, and an output signal is used for real-time detection of uric acid concentration. The device integrates minimally invasive sampling and high-sensitivity electrochemical detection, has the advantages of quick response, simplicity and convenience in operation, good biocompatibility and the like, and is suitable for application scenes of continuous monitoring of uric acid, chronic disease management and the like.

The invention discloses a preparation method of an SERS / electrochemical two-channel aptamer biosensor for detecting AFB1, and relates to the technical field of biosensors and detection. Comprising the following steps: S1, preparing a capture probe Fe3O4 (at) Au (at) Ag (at) PAMAM (at) Aptamer by adopting a chemical stepwise synthesis method; s2, preparing a signal probe AuNs (at) 4-MBA (at) Ag (at) ssDNA by adopting a chemical stepwise synthesis method; s3, PAMAM is deposited on the surface of the screen-printed electrode through an electro-deposition method, the aptamer is modified through a glutaraldehyde method, and Apt / PAMAM / SPGE is obtained; the screen printing electrode is used as a sensor substrate, and compared with a traditional three-electrode sensor, the sensor is easy to process, low in cost, small in size and easy to integrate. According to the signal probe, gold nanoparticles (AuNPs) grow into gold nanostars (AuNs) in an anisotropic mode, a Raman signal factor wrapped by an AuNs-Ag core-shell structure is prepared, and the excitation intensity of a Raman signal is remarkably improved by means of the multi-metal coupling effect between a capture probe and the signal probe.

The invention relates to a dual-mode paper-based sweat chloride ion sensor, a preparation method and application of the dual-mode paper-based sweat chloride ion sensor in rapid diagnosis of cystic fibrosis, and belongs to the crossing field of a biomedical detection technology and electrochemical / optical sensing materials and devices. The dual-mode paper-based sweat chloride ion sensor is composed of a colorimetric detection module and an electrochemical detection module. According to the invention, by optimizing the collaborative design of the colorimetric module and the electrochemical module and combining the integrated process of the silver nitrate / potassium chromate sensitive layer and the screen-printed electrode, the detection sensitivity limit is remarkably broken through, and the integrated process from preliminary screening to clinical definite diagnosis is realized. More importantly, a low-cost cellulose substrate and a silk-screen printing process are adopted, the single-time detection cost is lower than 0.1 dollar, the 180-second quick response characteristic is combined, the method completely meets the economical, practical, high-sensitivity, good-specificity, simple and quick to operate and repeatable diagnosis standards proposed by WHO, and the method is suitable for instant detection scenes of basic medical institutions.

A wearable diagnostic electrocardiogram (ECG) garment is disclosed herein. The wearable diagnostic ECG garment comprises a garment body, screen-printed electrodes positioned on the body, and screen-printed wires positioned in the garment body, each of the screen-printed wires connected from a central connector module to a screen-printed electrode.

The invention relates to an electrochemical analysis method and platform compatible with screen-printed electrodes (SPE) (27) and any potentiostat (2) designed for cell-based tests, enabling cells to maintain healthy proliferation while being shielded from external influences.

The invention discloses a method for ultrasensitive electrochemical detection of port carp spring viremia virus based on gold nanoparticle signal amplification, comprising the following steps: S1. preparing MBs-probe 1; S2. preparing AuNPs-probe 2; S3. preparing AuNPs-probe 4; S4. gold-plating the surface of the screen-printed electrode and covalently modifying the nucleic acid probe on the surface, then adsorbing hexaamine ruthenium, performing electrochemical determination, and obtaining the concentration of SVCV. The present invention establishes an ultrasensitive portable electrochemical detection method for SVCV based on the principle of gold nanoparticle signal amplification adsorbed by hexaamine ruthenium by combining high-affinity probes, which can amplify the signal geometrically, greatly improve the sensitivity, and the detection limit of SVCV is 0.0646nM, the recovery rate is 95%-102%, the specificity is high, the stability and reproducibility are good, the operation is simpler, the time required for detection is shortened, and the detection efficiency is improved.

The utility model discloses a metformin hydrochloride electrochemical analysis device which comprises a shell, and one side of the shell is provided with an electric sensor interface; the power supply unit is arranged in the shell and is used for generating polarization voltage; the silk-screen printing electrode electric sensor is electrically connected with the power supply unit and comprises a flexible electrode base body, a working electrode, a counter electrode, a reference electrode, an insulating layer, a wiring terminal and an electrode connecting wire, and the working electrode, the counter electrode, the reference electrode, the insulating layer, the wiring terminal and the electrode connecting wire are arranged on the flexible electrode base body; the surface of the working electrode is modified with an imprinted polymer with selective recognition on metformin hydrochloride; the signal processing unit is arranged in the shell and comprises a shunt resistor, an operational amplifier, a signal converter, a data storage chip and a microprocessor which are electrically connected in sequence; the display screen is electrically connected with the microprocessor and is used for displaying the converted concentration value; the method has the advantages that the metformin hydrochloride can be rapidly and accurately detected, and the use is relatively convenient.

The invention belongs to the technical field of electrochemical analysis and detection, and particularly relates to an electrochemical immunosensor for detecting adiponectin as well as a preparation method and application of the electrochemical immunosensor. The preparation method comprises the following steps: (1) connecting a screen-printed electrode SPCE to an electrochemical workstation by using a 0.01 M PBS (Phosphate Buffer Solution) with the pH value of 7.4, performing-0.2 V-1. 2V cyclic voltammetry scanning, and activating for 10 circles under 50mV / S; and (2) by taking 0.01-1M H2SO4 as a base solution, connecting the screen-printed electrode SPCE to an electrochemical workstation, carrying out electro-polymerization on poly-o-phenylenediamine in a 50-100mM o-phenylenediamine and NH2-UiO-66 solution to form a poly-o-phenylenediamine and NH2-UiO-66 composite modified electrode, washing with deionized water, and drying at room temperature. (3) soaking the modified electrode in a glutaraldehyde solution for 10-70 minutes, cleaning with deionized water, drying at room temperature, adding 10-100 [mu] L of ADPN antibody solution and 100-600 [mu] g / mL of ADPN antibody solution, and incubating; and (4) washing with ionized water, drying at room temperature, preventing non-specific binding sites at 37 DEG C for 0.5-1.5 hours by using 3-10 microliters of 0.8-1.2 wt% casein solution, and washing the screen-printed electrode again to obtain the electrochemical immunosensor.

The invention relates to a surface modified Fe / Cu-Co3O4 catalyst for nitrite detection and a preparation method thereof, a sensor and application, and the preparation method comprises the following steps: dissolving a cobalt source, an iron source, a copper source, urea and NH4F in deionized water, carrying out a hydrothermal reaction, washing, drying and calcining to obtain a Fe and Cu co-doped Co3O4 nanotube; and pre-hydrolyzing by using a KH792 silane coupling agent ethanol-water solution, and reacting with nanotubes to prepare the surface modified catalyst. The sensor takes carbon cloth or a screen-printed electrode subjected to ultrasonic cleaning and plasma treatment as a substrate, catalyst ink is coated to form a catalytic layer, and the catalytic layer, a platinum counter electrode and a silver / silver chloride reference electrode form a three-electrode system. Through molecular modification and material design, the interfacial force between the catalyst and nitrite is improved, the electrode stability is enhanced, and the catalyst is applied to a disposable printed electrode and portable detection equipment, so that high-sensitivity, stable and portable detection of nitrite is realized.

The application provides an electrochemical sensing ELISA reagent card, comprising a microfluidic channel body and an electrochemical sensor body which are bonded together, wherein: a plurality of "annular" liquid flow channels are arranged on the microfluidic channel body, each "annular" liquid flow channel is formed by a working electrode covering flow channel and a counter electrode and a reference electrode covering flow channel in series, and the "annular" liquid flow channels are communicated through a common flow channel; the electrochemical sensor body comprises a flat plate substrate and a plurality of screen-printed electrodes which are printed in parallel on the flat plate substrate, and each screen-printed electrode comprises a working electrode, a counter electrode and a reference electrode. The electrochemical sensing ELISA reagent card combines an electrochemical biosensor and a microfluidic chip, and solves the technical problems of large sample / reagent consumption, single detection index and liquid volume influence on absorbance measurement of a traditional ELISA reagent kit.

The invention relates to the technical field of electrochemical sensing, in particular to a multi-channel electrochemical aptamer sensor and a preparation method and application thereof.The multi-channel electrochemical aptamer sensor adopts a commercial silk-screen printing electrode and is combined with a polymer substrate material for amplifying electrochemical signals, and the electrochemical aptamer sensor is prepared. According to the present invention, the corresponding aptamer is fixed by using the gold nanoparticle through the chemical bond so as to specifically detect the three hemorrhage conversion biomarkers after acute cerebral infarction, such as human matrix metalloproteinase (MMP-9), fibrinogen (FN) and plasminogen activation inhibitor (PAI-1); wherein the FN and the PAI-1 are detected through an electrochemical aptamer sensor method for the first time, and simultaneous detection of the three biomarkers is realized through integration with commercial multi-channel micro electrochemical equipment.

The invention is applicable to the technical field of biological detection, and provides a method for detecting staphylococcus aureus based on combination of a screen-printed electrode and CRISPR / Cas13a, a probe containing a DNA / RNA hybrid chain is combined with a magnetic bead to form a simple composite structure, when the Cas13a recognizes 16sRNA of S. aureus, trans-cleavage activity can be immediately activated, the probe chain is rapidly cut off, the cut-off amount depends on the activated amount, and when the Cas13a recognizes 16sRNA of S. aureus, the Cas13a can be used for detecting staphylococcus aureus. And after transient magnetic separation, a result is observed on the screen-printed electrode. The method has ultrahigh specificity: the CRISPR / crRNA sequence ensures that staphylococcus aureus and other microorganisms can be accurately distinguished; the trans-cutting of Cas13a provides chemical amplification, and the magnetic separation purification greatly reduces background signals caused by non-specific adsorption, so that the signal-to-noise ratio and the sensitivity are remarkably improved.

The invention belongs to the technical field of electrochemical detection, and particularly relates to an enrofloxacin aptamer sensor based on a screen-printed electrode and a rapid detection method. The preparation method comprises the following steps: firstly preparing a Fe / Co two-dimensional MOF nanosheet with a lamellar structure by using a room temperature stirring method, then incubating with an enrofloxacin aptamer to prepare a nanosheet / aptamer probe, further incubating with enrofloxacin, mixing with an acetic acid-sodium acetate buffer solution, o-phenylenediamine and H2O2 to form a catalytic reaction system, and by combining with a screen-printed electrode-differential pulse voltammetry, detecting the content of the enrofloxacin. The enrofloxacin concentration of a sample to be detected is rapidly tested by drawing a quantitative analysis standard working curve, and rapid, simple and high-sensitivity detection of enrofloxacin is realized. The method is simple and rapid to operate, does not need expensive reagents, large-scale instruments and professional operators, is high in sensitivity, and can realize on-site, rapid and high-sensitivity quantitative detection of enrofloxacin in aquatic products such as grass-roots fish and shrimps in combination with a portable electrochemical detector.

The application discloses a self-driven disc type blood separation and detection device and method, which comprises a sample adding layer, a separation layer and a detection layer, and the layers are sequentially connected through screw fixation. The sample adding layer is provided with a sample adding port and a first screw hole; the separation layer comprises four repeated blood separation units and a second screw hole, and each separation unit comprises a sample inlet, a micro-fluidic channel, a filter groove, a sample outlet and a waste liquid collecting chamber; and the detection layer is provided with a screen-printed electrode interface and a third screw hole. Blood samples are dripped into the device from the sample adding port, and under the driving of the internal negative pressure of the device, the blood samples enter the micro-fluidic channel, and blood filtration is realized by using the gravity difference between blood cells and blood plasma. The filtered blood plasma flows into the detection layer and contacts with the screen-printed electrode detection unit, so that electrochemical detection is realized. The device does not need external power supply, thereby reducing sample operation, reducing the volume of the separation device, improving the blood separation efficiency, and facilitating instant detection and multi-channel detection of blood samples.

The invention provides an electrochemical voltammetry spectrum acquisition method for flower and fruit traditional Chinese medicinal materials, and belongs to the technical field of chemical detection. The method comprises the following steps: firstly, extracting flower and fruit traditional Chinese medicinal materials, then mixing an extracting solution with an acidic buffer solution, adjusting the pH value of a detection solution, and then collecting an electrochemical cyclic voltammetry map by adopting a carbon nanotube modified screen-printed electrode. After the carbon nanotube modified screen-printed electrode is combined with an acidic buffer solution, phenol and acid electroactive substances in the flower and fruit traditional Chinese medicinal materials can stably exist in the acidic environment, and after the phenol and acid electroactive substances are rapidly transferred by the carbon nanotube and grabbed by surface oxygen-containing groups, the phenol and acid electroactive substances in the flower and fruit traditional Chinese medicinal materials can be rapidly absorbed by the carbon nanotube. The electrochemical redox behavior from no to existence or from weak to strong is shown in a cyclic voltammetry curve, and the establishment of the electrochemical voltammetry fingerprint spectrum of the flower and fruit traditional Chinese medicinal materials is facilitated. The acquisition method provided by the invention is a universal acquisition method suitable for electrochemical voltammetry maps of flower and fruit traditional Chinese medicinal materials.

The invention discloses a portable electrochemical biosensor for detecting vibrio parahaemolyticus, the principle of the invention can be also suitable for detection of other pathogenic microorganisms, and the portable electrochemical biosensor comprises a PVC substrate, a sample pad, a capture pad, a screen printing electrode and a water absorption pad. According to the invention, the advantage of high sensitivity of electrochemistry and the advantage of no separation of the test strip are combined together, the vibrio parahaemolyticus is captured by using the aptamer and is fixed on the detection line, the signal probe is dropwise added, the electrochemical workstation is used for detection, and quantitative detection of the vibrio parahaemolyticus is realized by adopting a signal subtraction output mode. The method has the advantages of low cost, high detection speed, high sensitivity, simplicity in operation and the like. The requirements of customers for on-site rapid detection can be met, and food poisoning of patients can be effectively prevented.

The invention discloses a preparation method and application of a double-signal amplification unmarked electrochemical sensor for simultaneously detecting Pb < 2 + > and Hg < 2 + >. The sensor comprises a screen-printed electrode, a Ti3C2-Au layer and a MnO-SC layer, wherein the Ti3C2-Au layer and the MnO-SC layer are sequentially modified on the surface of the screen-printed electrode from inside to outside, and the MnO-SC layer is formed by annealing sulfur-containing Mn-MOF. The application of the sensor comprises detection of Pb < 2 + > and Hg < 2 + > in river water and tap water. Wherein the redox peaks of Pb < 2 + > and Hg < 2 + > are used as index signals, and no extra signal label is required to be introduced. When Pb < 2 + > and Hg < 2 + > are detected, the MnO-coated SC / Ti3C2-Au / SPEC modified electrode is used as a working electrode, the Ag / AgCl electrode is used as a reference electrode, the carbon electrode is used as an auxiliary electrode, and differential pulse voltammetry is adopted for detection. The linear range of the sensor is 0.25-50 [mu] M, and the detection limits of the sensor are 26.7 nM and 20.1 nM respectively. The sensor prepared by the invention shows excellent selectivity, reliability and repeatability on Pb < 2 + > and Hg < 2 + > in river water and tap water.

The invention provides a method for rapidly detecting pesticide residues in fruits and vegetables, and belongs to the field of pesticide analysis and detection. The method comprises the following steps: mixing a copper nanoparticle / reduced graphene oxide / chitosan composite material, acetylcholin esterase, choline oxidase and a cross-linking agent glutaraldehyde solution for reaction to obtain a double-enzyme functionalized nano composite material; dispensing a chitosan solution on the surface of a working electrode of a screen-printed electrode, drying to form a film, and covalently modifying the surface of the electrode with the bienzyme functionalized nano composite material through a cross-linking agent glutaraldehyde to obtain a sensing electrode; according to the method, acetylcholine is taken as a substrate, a sensing electrode is used, a chronoamperometry is adopted, inhibition ratios of pesticide standard substance solutions with different known concentrations to electrode response current are detected, and a standard curve between the pesticide concentration and the current inhibition ratio is established; and calculating the pesticide residue concentration in the fruit and vegetable sample to be detected according to the current inhibition ratio of the liquid to be detected and the standard curve. Therefore, the sensitivity and accuracy of pesticide residue detection in fruits and vegetables are improved.

The invention discloses a preparation method of an electrochemical immunosensor for detecting adiponectin and a method for quantitatively detecting the adiponectin by adopting the electrochemical immunosensor, provides a new strategy for fixing an adiponectin antibody by a one-step method, and constructs the electrochemical immunosensor based on a gold sputtering silver wire screen printing electrode (Au / AgSPE). The rapid, high-sensitivity and stable detection of the adiponectin is realized, so that the conversion of the adiponectin detection technology to instant detection application is promoted. Only a portable electrochemical workstation is needed in the detection process, and large biochemical analysis equipment is not needed. And the screen printing electrode and the sputtering technology support large-scale production, and cost reduction and popularization are facilitated.

The invention relates to a screen-printed electrode and a method for detecting the insulating property of the screen-printed electrode, and the screen-printed electrode comprises a substrate, a first electrode, a second electrode and an insulating layer. The first electrode, the insulating layer and the second electrode are sequentially printed on one side of the substrate; the first electrode comprises a first substance, and the second electrode comprises a second substance; when the first substance is in contact with the second substance, second target light is generated on the surface of the second electrode under the irradiation of the first target light; the second target light is used for detecting the performance of the insulating layer. Whether the insulating layer works normally or not is judged by judging whether the first electrode and the second electrode are short-circuited or not, so that the large-range insulation performance detection of the insulating layer of the screen-printed electrode is realized.

The invention discloses a method for detecting the concentration of acetic acid in an anaerobic fermentation system by using a bioelectrochemical sensor, acetic acid is detected by using the bioelectrochemical sensor, the bioelectrochemical sensor comprises a screen-printed electrode, and the working surface of the screen-printed electrode is modified with reduced graphene oxide and polymethylene blue. The working surface of the screen printing electrode is connected with acetokinase, pyruvate kinase and lactic dehydrogenase through a cross-linking agent. According to the method, the adopted sensor has better conductivity, higher response speed and higher current intensity, when the sensor is used for detecting the concentration of acetic acid in a fermentation system, the sensor has the advantages of being easy to operate, low in sample consumption, low in price, high in accurate measurement precision, high in detection speed and the like, and rapid detection of the concentration of acetic acid can be achieved; the acetic acid concentration in the anaerobic fermentation process in different periods can be timely and accurately obtained, effective data can be provided for anaerobic fermentation analysis, and the method has important significance for monitoring the process stability of anaerobic fermentation.

The invention provides a copper ion interference eliminating method for electrochemically detecting the content of lead ions and cadmium ions. The technical problems of membrane pollution and blockage, high membrane maintenance and replacement cost, interference caused by introduction of additional metal ions, need of accurate control of the use amount of a masking agent and the like in the existing method adopting a heavy metal membrane and the masking agent are solved. The method comprises the following steps: based on a three-electrode system, carrying out i-t enrichment on a solution to be detected in an electrochemical cell of an electrochemical workstation by using a screen-printed electrode, setting the enrichment potential to be-0.5 V to-0.4 V, and setting sufficient enrichment time to complete enrichment of copper ions; after the enrichment is finished, replacing the screen-printed electrode with an acidified carbon nanotube / Nafion composite screen-printed electrode containing a three-electrode system, and detecting the content of lead ions and cadmium ions in the solution to be detected by using an electrochemical workstation and selecting a square wave anodic stripping voltammetry; the method can be widely applied to the technical field of heavy metal ion detection.

The invention belongs to the technical field of electrochemical analysis and detection, and particularly relates to a screen-printed electrode for detecting Cu < 2 + > in a water sample and a detection method. The screen-printed electrode is composed of a graphite electrode and SA / SiO2 for modifying the surface of the graphite electrode; the preparation method of the screen-printed electrode comprises the following steps: S1, preparing a gel matrix; s2, preparing composite gel; and S3, electrode coating. According to the method for detecting the Cu < 2 + > in the water sample by adopting the screen-printed electrode, the linear concentration range of the detected Cu < 2 + > is 24.41-6250nM, the detection lower limit is estimated to be about 0.16 nM and is lower than the drinking water middle limit value (-15mu M) required by the World Health Organization (WHO) (-30mu M) and the Ministry of Environmental Protection in China, and the method is suitable for environments such as on-site water quality analysis or heavy metal pollution monitoring, family self-inspection and the like which are seriously deficient in resources.