71 results about "Lactate oxidase" patented technology

The invention discloses a method for detecting lactic acid by a visual electrochemical luminescence sensor based on a bipolar electrode array-micro-fluidic chip, and belongs to the technical field of biosensors. Based on lactate oxidase / carbon nano tube / chitosan modified electrode, bipolar electrode and micro-fluidic chip technology, the lactic acid can be visually detected by electrochemical luminescence imaging. As a bipolar electrode is a conductive material capable of performing electrochemical reaction at the tail end without external electric contact, bulk array analysis is conveniently performed, mass production is facilitated, and detection cost is reduced. The electrochemical luminescence imaging technology has the advantages of high sensitivity, simple light path and the like and is used for visually detecting the lactic acid, the method is simple and convenient, and results are visual.

The invention belongs to the technical field of pyruvic acid preparation method, and relates to a method for preparing pyruvic acid through a process of converting DL-lactic acid by using lactic acid oxidase (LOD) and catalase (CAT) in Pseudomonas fluorescens. The invention provides a method for preparing pyruvic acid through a process of converting DL-lactic acid by using lactic acid oxidase (LOD) and catalase (CAT) in microbe bacterial strain (ATCC 948)-Pseudomonas fluorescens crude enzymes liquor. According to the invention, the conversion rate of the products can be raised and the products stability can be maintained.

A process for preparing pyruvic acid by use of lactate oxidase or the complete cell containing said enzyme to transform DL / L-lactic acid includes choosing bacterial strain, slant culture, seed culture, culture in fermentor, collecting thalluses, transform experiment and separating specimen. Its advantages are simple process, low cost, and high transform efficiency.

The invention relates to a preparation method of a three-dimensional graphene lactic acid sensor. The preparation method comprises the following steps: promoting growth of a three-dimensional graphene nano wall by virtue of a plasma-enhanced chemical vapor deposition method by taking a copper foil as a substrate; drifting a three-dimensional graphene block on the surface of an Fe(NO3)3 solution so as to etch the copper foil, cleaning the copper foil by virtue of ultra-pure water and transferring the copper foil to a polyethylene terephthalate (PET) base material; printing three electrodes on the surface of the three-dimensional graphene / PET by virtue of a screen printing technology, and immobilizing lactase oxidase on the surface of the three-dimensional graphene by virtue of a chitosan-glutaraldehyde cross-linking method, so as to conduct functionalizing treatment on the electrodes; and finally, conduct sensitivity, stability, real-time performance and specificity lactic acid detection on the electrodes with the assistance of an electrochemical workstation, so that the required three-dimensional graphene lactic acid sensor is obtained. According to the preparation method disclosed by the invention, the three-dimensional graphene lactic acid sensor is prepared in a mode of being economic and environment-friendly, simple and efficient and controllable in quality, and due to the graphene nano wall which has the advantages of being rich in three-dimensional conductive network structure, huge in specific surface area and the like, the sensitivity and the real-time performance of lactic acid detection can be effectively improved; and the sensor is applicable to the fields of medical care and health.

The invention relates to a lactic fermentation quality measuring method of a wine malic acid, which belongs to the technical field of biosensors. The method adopts the following preparation steps: an L-lactic acid oxidase is solidified and combined with an H2O2 electrode into a biological L-lactalase electrode sensor, a phosphate buffering liquid with the pH of 7.2 and the mole weight of 0.1 millimole per liter <-1> and a standard liquid containing 500 milligram <-1> of the L-lactic acid in each liter are adopted, the instrument automatically displays the base enzyme membrane activity in 20 seconds after 25 microliter of the standard liquid is injected into a reaction pool, a calibrate button is pressed for 500 calibration, and the instrument is automatically cleaned and can be used for sample measurement again.

The invention discloses a graphene-modified lactic acid biosensor. The graphene-modified lactic acid biosensor comprises a substrate, a reference electrode, a counter electrode, a working electrode and an insulating layer, wherein the reference electrode, the counter electrode and the working electrode are parallely arranged on the substrate; the insulating layer partially coats the surfaces of the reference electrode, the counter electrode and the working electrode; the insulating layer and the exposed parts of the reference electrode, the counter electrode and the working electrode define a reaction chamber; the working electrode comprises a carbon paste lead, a graphene layer and an enzyme liquid layer; the graphene layer covers a reaction zone of the carbon paste lead; and the enzyme liquid layer is located in the reaction chamber and bonded with the graphene layer and contains lactic acid oxidase and an enzyme active additive.

We provide a lactate biosensing strip comprising a working electrode and a reference electrode, the two electrodes being deposited on an electrically insulated base support, the working electrode being formed by immobilizing lactate oxidase and an electron mediator on an inorganic graphite matrix and the graphite layer being deposited on a silver layer of the working electrode and the reference electrode being formed by depositing silver chloride on a silver layer of the reference electrode.

A method for preparing valuable sialic acid by cheap sodium lactate through multi-step coupling biotransformation is disclosed. It includes culture containing lactic oxidase strain, construction and culture of E.coli HB101(pBV220-ALD), preparation of N-acetylmannosamine, sialic acid converting synthesis by complete cell containing lactic oxidase and sialic aldolase with cheap sodium lactate as precursor, and separation and purification of sialic acid by ion exchange. It achieves low cost, simple operation and extensive converting conditions.

A highly thermo-stable lactate oxidase has been provided by, in the lactate oxidase obtained from Aerococcus viridans, modifying the 6 amino acid residues.

The invention relates to a lactate sensor, and specifically a lactate sensor capable of accurately measuring a lactate concentration in a short period of time. The lactate sensor includes an insulating substrate, an electrode system including at least a working electrode and a counter electrode provided on the substrate, and a reagent layer provided on the electrode system. The reagent layer contains lactate oxidase, a mediator, and N-(2-acetamide)-2-aminoethanesulfonic acid.

Embodiments of the present disclosure relate to stabilized lactate oxidase compositions, and electrodes, sensors and systems that include the same. Also provided are methods for making the compositions and for detecting and / or measuring lactate in vivo with stable lactate enzyme compositions.

The present invention provides a lactate biosensing strip comprising a working electrode and a reference electrode, the said two electrodes being deposited on an electrically insulated base support, the working electrode being formed by immobilizing an enzyme lactate oxidase and an electro mediator on an inorganic graphite matrix and the graphite layer being deposited on a silver layer and the reference electrode being formed by depositing silver chloride on an another silver layer.

The invention discloses a D-lactate oxidase. An amino acid sequence of the D-lactate oxidase is as shown in SEQ ID NO.2, and the D-lactate oxidase is soluble protein, wherein a cofactor is FAD; the optimum temperature is 55 DEG C; the optimal pH is 8.0; the D-lactate oxidase has over 60% enzyme activity within a pH range of 7.0-9.0; the D-lactate oxidase is capable of catalyzing D-lactic acid oxidation to generate pyruvic acid and hydrogen peroxide by employing molecular oxygen as a direct electron acceptor; when the concentration of D-lactic acid is within the range of 0.1-1.3mmol / L, the concentration of hydrogen peroxide generated by enzyme catalysis has a linear correlation with the initial D-lactic acid concentration; the appearance Km and Vmax of the D-lactate oxidase to the D-lactic acid are respectively 3.62+ / -0.53mmol / L and 0.52+ / -0.05U / mg; and the appearance Km and Vmax of the D-lactate oxidase to another substrate O2 are respectively 0.16+ / -0.01mmol / L and 0.97+ / -0.03U / mg. The D-lactate oxidase disclosed by the invention can be used for preparing a biosensor for detecting D-lactic acid by determining the concentration of hydrogen peroxide; and simple and rapid quantitative determination of D-lactic acid is realized.

The effect of the invention is to disclose a preparation method of a lactic acid fluorescent nano biological probe based on the enzyme catalytic reaction of the cobalt ion coordination type boron quantum dots. The preparation method comprises the following steps: by taking boron powder as a precursor, in the presence of cobalt ions, preparing cobalt ion coordinated boron nanosheets by adopting an ultrasonic-assisted liquid phase stripping method, adding glutathione (GSH), and carrying out solvent heat treatment on a mixed solution, so as to prepare the novel GSH surface modified cobalt ion coordinated boron quantum dots Co-coated BQDs. In the presence of lactate oxidase LOx, lactic acid LA is catalytically oxidized by LOx enzyme to generate pyruvic acid and hydrogen peroxide H2O2, and fluorescence of Co-BQDs is quenched under the oxidation effect of H2O2. By fitting the linear relationship between the fluorescence emission peak intensity of the Co-BQDs and the LA concentration in the corresponding mixed system, the fluorescent nano biological probe based on the Co-BQDs and LOx enzyme catalytic reaction is constructed, and is used for high-specificity quantitative detection of lactic acid in biological fluid.

The invention relates to a preparation method of a lactic acid biosensor, and belongs to the technical field of lactic acid or lactate detection. The method comprises the following specific steps: preparing a copper nanowire modified electrode, electrodepositing the copper nanowire modified electrode to grow copper-iron prussian blue in situ, and immobilizing lactate oxidase. On the basis of an electrochemical deposition method, Cu / FePBA grows in situ on a certain amount of copper nanowires through electro-deposition, and growth of the nano material is regulated and controlled by adjusting theelectro-deposition method and electro-deposition conditions, so that the catalytic activity and conductivity of the material are regulated and controlled. According to the invention, the biosensing electrode with high catalytic activity and high conductivity is prepared by utilizing an electro-deposition technology, and the high-performance lactic acid biosensor is prepared by combining lactic acid oxidase. The method disclosed by the invention is simple in preparation and high in repeatability, and the prepared lactic acid biosensor has relatively high sensitivity and relatively wide linearrange on lactic acid and lactate.

The invention belongs to the technical field of enzymatic catalysis, and particularly relates to a method for coupling production of sodium pyruvate by co-expressing L-lactate oxidase and hydrogen peroxide. Aiming at the problem that an enzymatic conversion method in an existing synthetic method of pyruvic acid is higher in cost and further is unsuitable for industrialization, the method is characterized by comprising the following steps: firstly, constructing a coexpression vector of the L-lactate oxidase and the hydrogen peroxide and transferring the coexpression vector into Escherichia coli; secondly, carrying out high-density fermentation on the Escherichia coli obtained in the first step to obtain L-lactate oxidase and hydrogen peroxide coexpressed Escherichia coli engineering bacteria; thirdly, putting a wet cell mass of the Escherichia coli engineering bacteria obtained in the second step into an L-sodium lactate solution, introducing sterile air, and stirring and transforming to obtain transformed liquid; and fourthly, carrying out microfiltration and ultrafiltration on the transformed liquid obtained in the third step to remove thalli and protein, and carrying out impurityremoval and alcohol precipitation to obtain the sodium pyruvate. The method disclosed by the invention is suitable for industrial production of the sodium pyruvate.

A lactate sensor capable of accurately measuring a lactate concentration in a short period of time. The lactate sensor includes an insulating substrate, an electrode system including at least a working electrode and a counter electrode provided on the substrate, and a reagent layer provided on the electrode system. The reagent layer contains lactate oxidase, it mediator, and N-(2-acetamide)-2-aminoethanesulfonic acid.

The invention discloses a method for preparing acetyl phosphate on the basis of biological enzymes. The method comprises the following steps: carrying out enzyme catalysis reaction on lactic acid and / or lactate and phosphoric acid and / or phosphate and / or biphosphate by using an immobilized oxidase lactate-immobilized pyruvate oxidase composite enzyme as a catalyst; and after the reaction finishes, filtering and precipitating to obtain the high-purity acetyl phosphate. The method is simple to operate, has the advantages of mild reaction conditions, high raw material conversion rate, low cost and environmental protection, and satisfies the industrial production.

Embodiments of the present disclosure relate to stabilized lactate oxidase compositions, and electrodes, sensors and systems that include the same. Also provided are methods for making the compositions and for detecting and / or measuring lactate in vivo with stable lactate enzyme compositions.

We provide a lactate biosensing strip comprising a working electrode and a reference electrode, the two electrodes being deposited on an electrically insulated base support, the working electrode being formed by immobilizing lactate oxidase and an electron mediator on an inorganic graphite matrix and the graphite layer being deposited on a silver layer of the working electrode and the reference electrode being formed by depositing silver chloride on a silver layer of the reference electrode.

The invention belongs to the technical field of biosensors, and particularly relates to a lactic acid biosensor which comprises a substrate, a carbon working electrode, a carbon counter electrode, a reference electrode and a lactic acid sensing film, wherein the carbon working electrode is an aminated graphite printing electrode, the lactic acid sensing film is formed on the surface of the carbon working electrode after lactic acid oxidase for establishing an electron transfer network is chemically crosslinked by a difunctional chemical crosslinking agent, and the lactic acid oxidase for establishing the electron transfer network is prepared by modifying electrochemically activated lactic acid oxidase by a carboxylated nano material. The electrochemical activation technology of the lactate oxidase is adopted, so that the lactate oxidase can perform direct electron exchange with the electrode, the sensitivity, accuracy, reproducibility, stability, specificity and anti-interference capability of dynamic detection of lactic acid can be improved, the service life of the implantable continuous lactic acid monitoring system is prolonged, and meanwhile, the cost of the lactic acid biosensor is greatly reduced.

The full blood lactic acid biosensor modified with oriented carbon nanotube features that one layer of Co particles as the catalyst for oriented growth of carbon nanotube is deposited on the substrate and that the reaction layer has base layer comprising oriented carbon nanotube as the second electric intermediate and the upper layer comprising L-lactic oxidase and the mixture of reagent, stabilizer and buffering liquid as the first electric intermediate. Compared with available the technology, the present invention has the advantages of obviously raised responding sensitivity on lactic acid concentration of the sensor, work voltage of the sensor lowered from 500 mv to 300 mv, no need of pre-treatment of the blood sample and blood sample amount as less as 2 microliter.

The invention discloses a metal organic framework nano-carrier as well as a preparation method and application thereof. The preparation method comprises the following steps that 5,10,15,20-tetra(4-carboxyphenyl)porphyrin, zirconium chloride, ferrous chloride, eight-arm amino polyethylene glycol, benzoic acid and N,N-dimethylformamide are mixed and stirred under the water bath ultrasonic condition, and a mixed solution is obtained; microwave heating treatment is carried out on the mixed solution to obtain a reaction product; and the reaction product is centrifuged, washed and dried to obtain the metal organic framework nano-carrier. The method provided by the invention has the advantages of simple steps and high production efficiency, and the prepared metal organic framework nano-carrier is good in dispersity and stronger in capability of catalyzing hydrogen peroxide to generate hydroxyl free radicals, can be used for loading lactate oxidase and a pyruvate kinase activator, can further improve the tumor treatment efficiency, and realize the efficient inhibition on tumors.

The invention discloses an electrochromic sensor array and a manufacturing method thereof, and successfully applies the sensor array to lactic acid detection. The sensor array comprises a plurality of sensors, wherein each sensor comprises a battery portion and a sensing portion; the sensing portion comprises a sensing electrode and a sample reaction pool; a working electrode of the sensing electrode is modified with a Prussian blue point; a cathode reaction zone and an anode reaction zone of the sample reaction pool comprises substrates made of paper and detection reagents; the detection reagent in the cathode reaction zone is a buffer solution containing lactate oxidase; the reaction reagent in the anode reaction zone is a buffer solution containing potassium ferricyanide. During lactic acid detection, the number of color changing points in an indication point array is different according to different concentrations of lactic acid to be detected. The concentration of the lactic acid can be judged by observing the number of color changing indication points with naked eyes. The sensor array is easy to manufacture, is convenient to use, does not need any detection circuit, and has a very good application value; a reaction result can be directly observed with the naked eyes.

The invention discloses a composition for inhibiting streptococcus mutans and an application of the composition in preparation of medicines for inhibiting the streptococcus mutans. The composition comprises lactobacillus plantarum, lactate oxidase and ferroferric oxide nano-enzyme. Lactic acid continuously secreted by the lactobacillus plantarum is continuously converted into hydrogen peroxide under the linkage catalytic action of the lactate oxidase and the ferroferric oxide nano-enzyme, and hydroxyl radicals better than the hydrogen peroxide in bactericidal activity are further generated, sothat the effects of sterilization and inhibition of biofilm formation are achieved. The composition exhibits a mild and sustained bactericidal effect. The lactobacillus plantarum-lactate oxidase-ferroferric oxide nano-enzyme composition provided by the invention can generate a relatively good inhibition effect on main pathogenic bacteria, namely the streptococcus mutans, of dental caries in the oral cavity and a biofilm formed by the streptococcus mutans, and can become a new means for preventing and treating the dental caries.

The invention belongs to the technical field of bioengineering, and particularly provides a preparation method of a lactate oxidase bioelectrode. The first aspect of the invention provides the preparation method of the lactate oxidase bioelectrode. The preparation method comprises the following steps: carrying out electrochemical oxidation treatment on a Pb electrode; and immobilizing an enzyme byusing an immobilized carrier. The invention provides the preparation method of the lactate oxidase bioelectrode. The method for preparing the bioelectrode through the electrochemical oxidation treatment on the Pb electrode and immobilization on a specific enzyme solution solves problems of low lactate oxidase immobilization rate and poor biocompatibility of an immobilization material. The methodrealizes high efficiency and repeatability of the lactate oxidase bioelectrode, and is an enzyme immobilization technology with high immobilization efficiency and good biocompatibility.

The invention relates to the field of graphene materials, and particularly relates to a preparation method and application of a thia-graphene / gamma-Fe2O3 nano composite material. A prepared thia-graphene / gamma-Fe2O3 nano composite material can be applied to the field of detection by a colorimetric method, and especially can be applied to the lactic acid detection by a colorimetric method via a microfluidic technique. The method for preparing thia-graphene / gamma-Fe2O3 can be used for obtaining gamma-Fe2O3 existing stably at the temperature of 650 DEG C. The obtained material thia-graphene / gamma-Fe2O3 can be widely applied to the fields of photoelectric chemical sensing, catalysis and battery materials. The obtained material thia-graphene / gamma-Fe2O3 can be applied to the flexible lactic acid detection by the colorimetric method via the microfluidic technique; the use amount of lactic acid and lactic acid oxidase is reduced by the microfluidic technique; meanwhile, the thia-graphene / gamma-Fe2O3 nano composite material is also reduced, and also can play a very good catalytic effect.

The invention relates to an electrochemical biosensor and a preparation method thereof. The electrochemical biosensor comprises a working electrode, and an enzyme layer, a carrier layer and a cross-linking layer are sequentially formed on the working electrode; the enzyme layer comprises glucose oxidase or lactate oxidase; the carrier layer is prepared from raw materials including at least one of chitosan, silicon dioxide, agarose and alginic acid or salts thereof; an the cross-linking layer is prepared from a raw material comprising a cross-linking agent. The electrochemical biosensor disclosed by the invention does not fall off or degrade after being monitored in vivo for a long time, and can keep the current stable for a long time.

The invention relates to a nanometre biosensor and its preparing method. The working electrode of the sensor consists of modifier nuclear capsid NR-SiO2 nanometer particle on the carbon electrode, dextrose oxydizing enzyme and lactate oxidase, L-glutematic oxidase, xanthic oxidase, etc. Thin layer detection cell is a hollow polytetrafluoroethylene film. The counter electrode consists of stainless steel electrode and a liquid inlet hole and outlet hole. The working electrodes, the thin layer detection cell and the counter electrode are set to a integration by screw. The preparation of the sensor is: first, modifying nuclear capsid nanometer particle onto the carbon electrode, after crosslink biological active enzyme and BSA with glutaraldehyde, modifying them on the nanometre NR-SIO2 layer, airing it dry and finish.it. The invention has the advantages of low cost, simple technique, and it can be used to detect various solutions containing dextrose with high sensitivity, stability, wide linear range and low detection line, with little demand of the sample quantity.

The present invention relates to a method for measuring lactic acid with high sensitivity, also relates to a lactic acid detection kit, and belongs to the technical fields of medical inspection and lactic acid bacterium fermented food measurement. The lactic acid detection kit is an important detection index for high altitude reaction, athlete training, severe diabetes and body acidosis caused byother reasons, and also an index for detecting lactic acid fermented food. The method uses an original lactate oxidase method, then pyruvate oxidase is introduced, one molecule of lactic acid reacts with the lactate oxidase and pyruvate oxidase to generate two molecules of hydrogen peroxide, then a Trinder reaction is conducted to generate red color, absorbance at a wavelength of 500-600 nm is detected, and content of the lactic acid is calculated. The method has advantages of high sensitivity, good repeatability, wide linearity and good stability, and is very practical for routine laboratoryapplication.