30 results about "Lactate oxidase" patented technology

The invention discloses a loose macroporous iron-based nano catalytic compound for inducing tumor para-apoptosis and a preparation method and application thereof.The nano catalytic compound (TF-Fe at LC) is prepared by taking a porous Fe3O4 nano cluster composed of single crystals as a carrier, modifying the surface of the carrier with an acid-responsive tannic acid-iron (TA-Fe < 3 + >) network and co-loading lactate oxidase (LOD) and a mitochondrial uncoupling agent CCCP in the carrier. The TF-Fe-coated LC constructed by the invention does not need additional chemotherapeutic drugs, and tumor cells are induced to generate a large amount of active oxygen through catalytic cascade and mitochondrial oxidative stress, so that parapoptosis of the tumor cells is triggered; the parapoptotic cells can play a role of a tumor vaccine, induce other tumor cells to generate immunogenic death, and activate an organism immune system to recognize and kill tumors. In addition, the nano catalytic system can be combined with drugs and immunosuppressants to realize a synergistic anti-tumor effect.

Disclosed herein is directed to a lactate oxidase variant that exhibits reduced affinity to lactate as compared to a wild-type lactate oxidase. The lactate oxidase variant has one or more amino acid substitutions occurring at positions 95, 96, and / or 175 of the wild-type amino acid sequence. Also disclosed herein is a method for detecting and quantifying lactate in various liquid samples by using the present lactate oxidase variant. The method mainly includes steps of contacting the liquid sample with said lactate oxidase variant; measuring a current generated by the reaction between the lactate oxidase variant and the lactate in the liquid sample; and determining the concentration of lactate in the liquid sample by interpolating or extrapolating the current with that of a control sample having a known concentration of lactate.

The invention relates to the technical field of nano biological medicines, and discloses a photo-thermal-enzyme catalysis nano-particle as well as a preparation method and application thereof. The photo-thermal-enzyme catalysis nano-particles are constructed by crosslinking water-soluble self-doped polyaniline nano-particles, human serum albumin, lactate oxidase and collagenase through a thioacetal linker capable of being split by active oxygen. Collagenase and lactate oxidase (LOx) are integrated into the same nanoparticle system through a thioacetal (TK) linker, the TK linker is split under the action of tumor microenvironment active oxygen (ROS) and H2O2 generated by catalysis of the LOx, the activity of the two enzymes is synchronously activated, a collagen matrix (physical barrier) is degraded, lactic acid (chemical barrier) is removed, the tumor microenvironment is efficiently remodeled, and the tumor microenvironment can be effectively inhibited. The problems that the regulation effect of a single barrier is limited, and the tumor microenvironment is difficult to improve are solved.

The application discloses an iron modified ZIF8 nanoparticle encapsulating an antitumor drug and a preparation method and application thereof, and belongs to the technical field of medicines. The preparation method of the nanoparticle comprises the following steps: firstly, preparing a zinc hydroxide loaded antitumor drug, then adding 2-methyl imidazole to obtain a ZIF8 nanoparticle encapsulating the antitumor drug, and finally adding Fe 2+ A methanol solution of a salt is reacted to obtain the iron modified ZIF8 nanoparticle encapsulating the antitumor drug. Through process improvement, the application loads an antitumor chemotherapy drug in the ZIF8 material, so that the ZIF8 material has good acid responsive drug release capacity. Through iron element modification, the nanoparticle is endowed with peroxidase activity, so that the nanoparticle can realize acid and hypoxia responsive chemotherapy and chemical kinetics therapy. The nanoparticle and microorganisms capable of producing lactate oxidase are combined to show super strong non-external field responsive precise tumor treatment capacity.

This invention provides a method for preparing and applying a nanosystem for regulating the osteogenic microenvironment. The nanosystem comprises catalase, lactate oxidase, and a strontium-containing mineralized nanolayer. Experiments demonstrate that this nanosystem can effectively treat bone aging-related diseases, and that catalase and lactate oxidase have a synergistic effect. This invention provides a novel treatment strategy for bone aging-related diseases and has broad prospects for clinical translation.

The invention relates to the technical field of novel biological materials, and particularly discloses an active oxygen and lactic acid dual-driven chemotactic nano motor and a preparation method thereof. Comprising lactate oxidase and selenium nanoparticles, the selenium nano-particles are formed by ascorbic acid and sodium selenite through a chemical reduction method, and the surfaces of the selenium nano-particles are modified with polysaccharide for stabilizing the selenium nano-particles; the lactate oxidase is loaded on the selenium nano-particles to form the nano-motor. Lactic acid is specifically consumed by loading lactic acid oxidase on the surface of the selenium nano-motor, due to high selectivity, the nano-motor can perform directional chemotactic movement towards a lactic acid high expression site, and the excellent oxidation resistance of selenium nano-particles can remove active oxygen and avoid oxidative stress damage, so that the lactic acid and the active oxygen are consumed at the same time.

This invention discloses an engineered *E. coli* strain that secretes lactate oxidase under hypoxia-induced conditions and its applications, relating to the field of biomedical technology. The engineered *E. coli* strain provided by this invention can responsively synthesize lactate oxidase in vitro and under culture medium conditions when exposed to a hypoxic environment. Lactate oxidase decomposes localized lactic acid to produce hydrogen peroxide, thereby killing cells and local bacteria. This process, while treating local symptoms, also kills the *E. coli* vector during culture, reducing the risk of exogenous infection caused by this engineered *E. coli* strain, making it a relatively safe therapeutic strain overall.

The invention discloses a preparation method and application of anti-tumor nano-particles based on lactate oxidase and Prussian blue. The nano-particles are hollow Prussian blue nano-particles (PBNPs), the surfaces of the hollow Prussian blue nano-particles (PBNPs) are modified with CXCR1 targeting polypeptide, and the surfaces of the hollow Prussian blue nano-particles (PBNPs) are internally loaded with lactate oxidase (LOD); the amino acid sequence of the CXCR1 targeting polypeptide is as follows: SAKELRCQCIKTYSKPFHPK, and the amino acid sequence of the CXCR1 targeting polypeptide is as follows: Comprising the following steps: S1, synthesizing through a polypeptide synthesizer, and grafting hydroxyl in the rhodamine fluorescent dye to amino of initial serine for tracing. By grafting the CXCR1 targeting polypeptide and loading the LOD catalytic enzyme, the nano catalysis-photo-thermal material (CXCR1-LOD at PBNPs) with targeting activity and biological enzyme activity can be successfully prepared. Through further in-vivo and in-vitro experimental studies, the anti-tumor effect and the molecular mechanism of the CXCR1-LOD coated PBNPs nano material can be fully confirmed. The material combines targeting property, catalytic property and photo-thermal property, and is a further improvement on early-stage research, so that a new strategy and a new method are provided for treatment of osteosarcoma.

Disclosed herein is directed to a lactate oxidase variant that exhibits reduced affinity to lactate as compared to a wild-type lactate oxidase. The lactate oxidase variant has one or more amino acid substitutions occurring at positions 95, 96, and / or 175 of the wild-type amino acid sequence. Also disclosed herein is a method for detecting and quantifying lactate in various liquid samples by using the present lactate oxidase variant. The method mainly includes steps of contacting the liquid sample with said lactate oxidase variant; measuring a current generated by the reaction between the lactate oxidase variant and the lactate in the liquid sample; and determining the concentration of lactate in the liquid sample by interpolating or extrapolating the current with that of a control sample having a known concentration of lactate.

The application relates to the technical field of biosensors, and discloses a metal nucleic acid framework nanocascade enzyme as well as a preparation method and application thereof. The preparation method of the nanocascade enzyme is as follows: nucleotide sequences shown in SEQ ID NO. 1-10 are mixed in an equimolar ratio, annealing reaction is carried out to obtain a metal template DNA nanosheet; the DNA nanosheet is reacted with a metal precursor to obtain the metal nucleic acid framework nanocascade enzyme. The metal nucleic acid framework nanocascade enzyme DNS-Fe has catalase activity, after corresponding aptamers are added, the DNS-Fe can accurately recognize target objects in various interferents, and the accuracy is high; DNS-Pt / Fe has lactic acid oxidase, glucose oxidase and sarcosine oxidase activity; DNS-Ag / Fe has uric acid oxidase activity; the combination of the DNS-Fe and the DNS-Ag / Fe can realize cascade action, replace natural catalase to catalyze hydrogen peroxide to generate free radicals, and the free radicals are reacted with chromogenic substances to generate a color reaction, and the results are easy to observe.

The invention belongs to the field of biological ceramic materials, and relates to a biological ceramic composite scaffold with a function of catalytically regulating lactic acid metabolism as well as a preparation method and application thereof. The biological ceramic composite scaffold with the function of catalytically regulating lactic acid metabolism comprises a ceramic scaffold matrix with gaps and enzyme-loaded hydrogel filled in the gaps of the ceramic scaffold matrix, and the enzyme-loaded hydrogel is hydrogel formed by loading lactate oxidase and catalase in macromolecular hydrogel. The composite scaffold can catalyze lactic acid to generate pyruvic acid, so that a lactic acid excess bone microenvironment at the initial stage of injury is adjusted, and further physiological behaviors of various cells such as macrophages and mesenchymal stem cells are adjusted, so that a bone microenvironment beneficial to bone defect repair is created, and osteogenesis is promoted.

This invention discloses a radiosensitizer with multi-enzyme activity, its preparation method, and its application in the preparation of antitumor agents. The radiosensitizer comprises rhodium-copper alloy nanoparticles, trithiol-terminated polymethacrylic acid modified on the surface of the rhodium-copper alloy nanoparticles, and lactate oxidase bound to the trithiol-terminated polymethacrylic acid. The preparation method involves mixing rhodium-copper alloy nanoparticles with trithiol-terminated polymethacrylic acid bound to their surface, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, and N-hydroxysuccinimide ester, stirring, adding lactate oxidase, and continuing stirring to obtain the radiosensitizer. This invention achieves precise assembly of the nanocarrier and enzyme-active components through modular design. This invention provides an efficient and safe solution for integrated tumor diagnosis and treatment, and has significant potential for industrial production.

The invention discloses a cascaded nano-enzyme with metabolic reprogramming as well as a preparation method and application of the cascaded nano-enzyme. The method comprises the following steps: firstly, synthesizing manganese and cobalt-based Prussian blue nanoparticles by adopting a precipitation method, and then carrying out calcination treatment in an ammonia gas atmosphere to finally obtain the target nano-enzyme. The nano-enzyme has the catalytic activity of lactate oxidase (LOX) and catalase (CAT) at the same time, and continuous cascade reactions of oxygen, lactic acid, pyruvic acid and hydrogen peroxide and hydrogen peroxide, oxygen and water can be achieved. Compared with a natural LOX enzyme with the same mass concentration, the nano enzyme shows more excellent catalytic activity and temperature stability in an acid environment (pH = 5). The nano enzyme has the following advantages: 1) metabolism regulation is realized through cascade catalytic reaction, and lactic acid is effectively consumed; 2) an anti-oxidation treatment effect is achieved by removing hydrogen peroxide; and 3) the pathological microenvironment of inflammatory tissues can be obviously improved. The invention provides a novel nano-enzyme solution for metabolism regulation and anti-oxidation treatment.

This invention discloses albumin nanoparticles co-loaded with flavin and lactate oxidase, their preparation method, and applications. Using human serum albumin as a carrier, flavin and lactate oxidase are simultaneously encapsulated at a mass ratio of 10:1, with a particle size of 150-180 nm and a polydispersity index of less than 0.2. This invention exerts its anti-hepatocellular carcinoma effect through mechanisms such as reducing lactate levels in the tumor microenvironment, inducing an increase in reactive oxygen species, inhibiting cGAS protein lactation modification, and activating the cGAS-STING signaling pathway. The nanoparticles exhibit high encapsulation efficiency and good stability. The flavin loaded on these nanoparticles can significantly reduce the reduction of pyruvate to lactate by inhibiting lactate dehydrogenase; simultaneously, the lactate oxidase loaded on these nanoparticles catalyzes the dehydrogenation of lactate to pyruvate. In other words, these nanoparticles synergistically regulate lactate metabolism through a two-way regulatory strategy of "reducing source and increasing sink"—"inhibiting lactate production" and "promoting lactate clearance"—significantly enhancing in vitro and in vivo anti-tumor effects, and demonstrating high biosafety.

A composite material contains: bovine serum albumin modified with neutral red; single-walled carbon nanotube inclusions; and lactate oxidase enzyme inclusions. A device for quantitatively assessing lactate content in body fluids comprises a working electrode, the surface of which is coated with the composite material according to the claimed invention. The technical result is that of increasing the upper limit of the range of detectable concentrations of lactate in body fluids to 57 mM, as well as reducing the time taken to perform a single measurement using the claimed device.

The application discloses a method for separating and extracting sodium pyruvate from enzyme conversion liquid for producing sodium pyruvate, which uses enzyme conversion liquid containing sodium pyruvate produced by catalyzing lactic acid with lactic acid oxidase as raw material, removes bacteria bodies, concentrates, sprays, dries and extracts the enzyme conversion liquid with an organic solvent, and comprises the following steps: 1) removing bacteria bodies by filtering the enzyme conversion liquid containing sodium pyruvate through a ceramic membrane; 2) adding activated carbon to perform decolorization treatment; 3) performing concentration by vacuum distillation, so that the content of sodium pyruvate in the enzyme conversion liquid is concentrated to 500-700 g / L; 4) performing spray drying; 5) adding an organic solvent, performing heating, stirring and reflux extraction, cooling to room temperature, centrifugation and drying, and thus pure sodium pyruvate is obtained. The method is simple in operation, low in organic solvent consumption and capable of completely recovering the organic solvent, the produced sodium pyruvate is white in color, the content of the sodium pyruvate is more than 99.6%, the one-time yield is about 96%, the method is low in energy consumption, high in yield and high in product purity, and can be large-scale industrialized production.

The invention relates to the technical field of sensor analysis and detection, in particular to a preparation method and application of a self-powered sensor for lactic acid detection, polystyrene spheres (PS spheres) are introduced into a copper-iron co-doped zeolite imidazole framework 8 (CoFe-ZIF-8) to prepare a precursor, and the precursor is carbonized to obtain a catalyst PS-Co1-Fe1-NC. The catalyst shows oxygen reduction (ORR) performance higher than that of commercial Pt / C under alkaline and neutral conditions, and when the catalyst is used for an alkaline zinc-air battery (ZAB) and neutral ZAB, the performance of the catalyst is better than that of a commercial Pt / C + RuO2 battery. A self-energized sensing platform is constructed by a biological cathode modified by PS (at) Co1-Fe1-NC and lactate oxidase (LOx) and a zinc sheet and is used for lactic acid detection. When lactic acid exists, LOx catalyzes lactic acid to decompose and consume oxygen and reacts with ORR to form an oxygen consumption competitive relationship, so that the open-circuit voltage is reduced, and the purpose of detecting lactic acid is achieved. The application of the self-energized sensor in lactic acid detection is widened, and the self-energized sensor has a wide linear range, high sensitivity and low detection limit for lactic acid detection.

The invention discloses a continuous lactic acid monitoring sensor and a preparation method thereof, and belongs to the technical field of electrochemical detection. The sensor comprises a substrate layer, an electrode layer and a reaction layer, the electrode layer is arranged on the substrate layer, and the electrode layer comprises a working electrode, a reference electrode and a counter electrode; the reaction layer is arranged on the working electrode, the reaction layer comprises lactate oxidase and catalase, the mass ratio of the lactate oxidase to the catalase is 1: (1-3), and the catalase is purified. The continuous lactic acid monitoring sensor provided by the invention is high in detection accuracy and high in stability, almost has no sensitivity attenuation after being worn in vivo for 10 days, and can meet the use requirements of wearing in vivo for real-time effective detection.

Disclosed herein is directed to a lactate oxidase variant that exhibits reduced affinity to lactate as compared to a wild-type lactate oxidase. The lactate oxidase variant has one or more amino acid substitutions occurring at positions 95, 96, and / or 175 of the wild-type amino acid sequence. Also disclosed herein is a method for detecting and quantifying lactate in various liquid samples by using the present lactate oxidase variant. The method mainly includes steps of contacting the liquid sample with said lactate oxidase variant; measuring a current generated by the reaction between the lactate oxidase variant and the lactate in the liquid sample; and determining the concentration of lactate in the liquid sample by interpolating or extrapolating the current with that of a control sample having a known concentration of lactate.

The invention provides electrochemical test paper for lactic acid detection and application thereof, and relates to the technical field of biomedicine. The electrochemical test paper for lactic acid detection comprises a test paper substrate, an electrode layer, a reagent layer, an insulating layer and a hydrophilic film layer, the reagent layer is obtained by coating a solution of the reagent layer, and the solution of the reagent layer comprises hydroxyethyl cellulose, polyvinylpyrrolidone, an electron transfer substance, a surfactant, an enzyme protective agent, lactate oxidase and a buffer solution according to a specific ratio in percentage by mass. According to the electrochemical test paper, in the presence of lactate oxidase and a medium, a current signal is transmitted through oxidation-reduction reaction, so that the concentration of lactic acid in blood is quantitatively detected, the electrochemical test paper is simple to operate, convenient to carry, high in semaphore and rapid and sensitive in detection, and the electrochemical test paper has important significance in the field of biomedicine.

The application discloses a continuous lactic acid monitoring sensor and a preparation method thereof, and belongs to the technical field of electrochemical detection. The sensor comprises a substrate layer, an electrode layer and a reaction layer, the electrode layer is arranged on the substrate layer, the electrode layer comprises a working electrode, a reference electrode and a counter electrode; the reaction layer is arranged on the working electrode, and the reaction layer comprises lactic acid oxidase and catalase, wherein the mass ratio of the lactic acid oxidase to the catalase is 1: (1-3), and the catalase is subjected to a purification treatment. The continuous lactic acid monitoring sensor provided by the application has high detection accuracy and high stability, has almost no sensitivity attenuation after being worn in the body for 10 days, and can meet the use requirement of real-time and effective detection when being worn in the body.

The invention develops a dual-mode optical sensor based on CuO2 nanodots. The dual-mode optical sensor is mainly applied to detection and research of a Warburg effect of gastric cancer. The CuO2 nanodots can catalyze the reaction of o-phenylenediamine (OPD) and hydrogen peroxide (H2O2), so that the color of the solution is changed from colorless to yellow along with the increase of absorbance and fluorescence intensity. Based on the reaction, a dual-mode sensor is designed, and the activity of lactic acid and lactate oxidase is synchronously detected through colorimetry and fluorescence. In the process of catalyzing lactic acid to generate H2O2 by lactic acid oxidase, the generated H2O2 promotes the color of a solution to change remarkably, so that the sensitive detection of the activity of lactic acid and oxidase thereof is indirectly realized. As the Warburg effect of the gastric cancer causes rise of the lactic acid level, the sensor can effectively associate the lactic acid level with the metabolic characteristics of the gastric cancer. In addition, in combination with an RGB colorimetric analysis technology, a smart phone is used for capturing color changes and carrying out image quantitative analysis, a portable, low-cost and high-sensitivity detection system is formed, and the application blank of the CuO2 nanodots in the field is filled up.

The invention discloses a recombinant engineering bacterium for producing recombinant lactate oxidase as well as a construction method and application of the recombinant engineering bacterium, and the construction method comprises the following steps: (1) introducing an HsoLOX gene for coding lactate oxidase into an expression plasmid to construct a recombinant expression vector containing the HsoLOX gene; the nucleotide sequence of the HsoLOX gene is as shown in SEQ ID NO.1 or a sequence of which the homology with the sequence as shown in SEQ ID NO.1 is greater than 90%; and (2) transforming the recombinant expression vector into host bacteria, screening positive clones by taking KanR as a screening marker, and culturing to obtain recombinant engineering bacteria. When the engineering strain is subjected to high-density fermentation for 46 hours, the relative enzyme activity of thalli is 1773 U / g, and the thalli density of a fermentation tank is 262.5 g / L. The invention further provides application of the recombinant lactate oxidase or the whole-cell catalyst and catalase in catalyzing L-sodium lactate together to generate sodium pyruvate, and the conversion rate can reach 99.5%. The operation method is simple and safe, low in production cost, mild in preparation condition, green and pollution-free, and has high economic value and social benefit.

The invention belongs to the technical field of clinical biosensing detection equipment, and relates to a preparation method of a chip for dynamically monitoring physiological indexes in an operation first-aid process. Adding ferric chloride and pyrrole monomers into the methylene orange solution, adding potassium ferrocyanide for continuous reaction after reaction, filtering, washing and drying to obtain the Prussian blue / polypyrrole tube composite material. Dropwise adding the Prussian blue / polypyrrole tube composite material dispersion liquid on a first working electrode and a second working electrode respectively, drying, then continuously dropwise adding a mixed solution A containing glucose oxidase and glutaraldehyde on the surface of the first electrode, and continuously dropwise adding a mixed solution B containing lactate oxidase and chitosan on the surface of the second electrode; and drying at low temperature to obtain the detection chip. The material is excellent in conductivity, high in sensitivity of a detection chip and high in stability. Glucose and lactic acid in serum can be dynamically monitored at the same time and do not interfere with each other.

The invention belongs to the technical field of biosensor preparation, and relates to a preparation method of a lactic acid and alpha fetoprotein detection biosensor. The preparation method comprises the following steps: adding single-layer graphene oxide into N, N-dimethylformamide, uniformly mixing, adding polyacrylonitrile, uniformly mixing, and adding dopamine hydrochloride to obtain a spinning solution; and after spinning with the spinning solution, drying in a vacuum drying oven, and then fixing on a gold electrode to obtain an electrode P. And uniformly mixing lactate oxidase and chitosan, dropwise adding the mixture to the surface of the electrode P, dropwise adding an antibody solution after drying, and performing secondary drying to obtain the sensing electrode. The nanofiber membrane with proper pore diameter and fiber diameter is regulated and controlled, is used for preparing a sensor for simultaneously detecting lactic acid and alpha fetoprotein, and has higher performance in detection of a real sample. The detection range of lactic acid and alpha fetoprotein is wide, the preparation process is simple, the cost is low, and the method can be used for large-scale production.

The invention relates to the technical field of biosensors, and discloses a metal nucleic acid framework nano cascade enzyme as well as a preparation method and application thereof. The preparation method of the nano cascade enzyme comprises the following steps: mixing nucleotide sequences as shown in SEQ ID NO.1-10 according to an equal molar ratio, and carrying out annealing reaction to obtain a DNA nanosheet of a metal template; and reacting the DNA nanosheet with a metal precursor to obtain the metal nucleic acid framework nano cascade enzyme. The metal nucleic acid framework nano cascade enzyme DNS-Fe has catalase activity, and after a corresponding aptamer is added, a target object can be accurately recognized in a plurality of interferents, and the accuracy is high; dNS-Pt / Fe has the activity of lactate oxidase, glucose oxidase and sarcosine oxidase, and DNS-Ag / Fe has the activity of urate oxidase, so that the cascade action can be realized by combining the DNS-Pt / Fe with the DNS-Fe, and the DNS-Ag / Fe replaces natural catalase to catalyze hydrogen peroxide to generate free radicals to be subjected to chromogenic reaction with a chromogenic substance, and the result is easy to observe.

The invention discloses a response type self-driven motor core-shell microneedle for treating intervertebral disc degeneration and a preparation method and application thereof, and relates to the technical field of biological medicine. The core-shell microneedle comprises a shell layer and a core layer, the shell layer is a biodegradable shell layer, and the shell layer comprises ureido pyrimidone grafted gelatin UPy-Gel, a bubble pump NaHCO3, and a metal phenolic aldehyde network HCA-Se / LOX formed by 3, 4-dihydroxyphenylpropionic acid loaded with lactate oxidase and selenium dioxide; the core layer is prepared from cyclodextrin / dihydrocaffeic acid grafted chitosan (CS-HCA-CD) and celecoxib, and the cyclodextrin / dihydrocaffeic acid grafted chitosan (CS-HCA-CD) and the celecoxib; wherein the metal phenolic network HCA-Se / LOX formed by 3, 4-dihydroxyphenylpropionic acid loaded with lactate oxidase and selenium dioxide is prepared by the following steps: dissolving lactate oxidase and dihydrocaffeic acid in a selenium dioxide solution, adding polyvinylpyrrolidone and an ascorbic acid solution, and reacting to obtain the metal phenolic network HCA-Se / LOX formed by 3, 4-dihydroxyphenylpropionic acid loaded with lactate oxidase. The metal phenolic aldehyde network HCA-Se / LOX is formed by 2, 4-dihydroxyphenylpropionic acid and selenium dioxide.

Disclosed herein is a printable liquid lactate sensor composition including silk fibroin in an amount by weight of between 0.1% and 30%, a lactate oxidase that is activated by lactate to produce hydrogen peroxide, a peroxidase that is activated by the hydrogen peroxide, and a chromogenic substrate that changes color upon activation of the peroxidase. Wearable sensors including the printable liquid lactate sensor composition are disclosed herein.

The invention discloses lactic acid metabolism regulation engineering bacteria as well as a construction method and application thereof. The lactic acid metabolism regulation engineering bacteria comprise chassis bacteria and recombinant plasmids, the chassis bacterial cell is EcN delta nlpI, and the EcN delta nlpI is an EcN strain with nlpI gene deleted and is used for enhancing release of outer membrane vesicles; the recombinant plasmid is used for enabling engineering bacteria to express tumor targeting molecules and lactate oxidase, and comprises a Myc-EGFP (Enhanced Green Fluorescent Protein) recombinant protein, a Myc-INP-HlpA-ClyA-EGFP-3 * Flag recombinant protein, a coding gene of the Myc-INP-HlpA-ClyA-LOx-3 * Flag recombinant protein, and a promoter. The lactic acid metabolism regulation engineering bacterium can target a tumor site, continuously express lactate oxidase at the tumor site, degrade lactic acid enriched in tumors and improve the radiotherapy effect.