32 results about "Paraoxon" patented technology

The invention discloses a method for preparing a mimic enzyme molecularly imprinted polymer microsphere for hydrolyzing organophosphorus. A paraoxon transient state analogue (4-nitro benzyl) phosphoric acid diethyl ester serves as a template molecule, 1-vinyl imidazole and methacrylic acid are functional monomers, a molecular imprinting technology is used, a precipitation polymerization method is adopted, and therefore the mimic enzyme molecularly imprinted polymer microsphere for hydrolyzing the organophosphorus is prepared, wherein the mimic enzyme molecularly imprinted polymer microsphere for hydrolyzing the organophosphorus is good in dispersibility and uniform in particle size. The paraoxon hydrolytic enzyme activity of the prepared molecularly imprinted polymer microsphere and the paraoxon spontaneous hydrolyzing are compared, the hydrolyzing efficiency can be improved by 188 times to the maximum and is also improved by 2.3 times compared with the catalyzing efficiency of a non-imprinted polymer synthesized under the condition of not adding template molecules, a measured Km value and a measured Vmax value are 0.064 mmol / L min and 2.41 mmol / L respectively, and Kcat is 0.237 / S. The prepared mimic enzyme molecularly imprinted polymer microsphere for hydrolyzing the organophosphorus can be used for efficiently hydrolyzing organophosphorus pesticide and can also be used for degrading and destroying organophosphorus nervous toxic agent chemical weapons.

The invention discloses preparation and application of a graphene composite fiber nonwoven fabric for catalytically degrading neuropathic chemical warfare agents, and belongs to the field of chemicalprevention. MOFs (Metal Organic Frameworks) nanoparticles are synthesized on the surface of fibers by a solvothermal method by using graphene fibers as carriers, wherein the diameter of the graphene fibers is 20 to 100 [mu]m; an MOFs catalyst is UiO-66-NH2; the particle dimension is 50 to 400 nm; and the composite fiber nonwoven fabric is graphene@UiO-66-NH2, and the thickness is 50 to 300 [mu]m.The graphene composite fiber nonwoven fabric is prepared through wet spinning and subsequent vacuum suction filtration, and has an efficient photothermal conversion effect. Under the condition of simulated sunlight, the catalytic degradation half-life period of the graphene@UiO-66-NH2 on an optimum analog of methyl paraoxon of a nerve poison of GD is 1.6 min; complete degradation can be almost realized within 20 min; and excellent capability of fast and catalytically degrading the neuropathic chemical warfare agents is shown.

The invention discloses a metal-organic coordination polymer with the organophosphorus hydrolase activity and a preparation method and application thereof. The structural unit of the polymer is [Zn(L1)0.5(L2)0.5].3DMF, wherein L1 represents 1,3-bis[di(2-diazole)-hydroxymethyl]phenyl, L2 represents 3,3',5,5'-biphenyl tetracarboxylic acid ions containing four carboxyls with no proton, DMF represents N,N-dimethyl formamide, and two DMF solvent molecules are out of order. The polymer belongs to a monoclinic system and a C2 / c space group. The polymer is synthesized under the low temperature through a solvothermal method, substrate organophosphorus can be effectively hydrolyzed, when pH is equal to 9.0, the ethyl paraoxon hydrolysis activity of the 0.1 mg / mL polymer is about 28 times the hydrolysis activity with no polymer, the Vmax of ethyl paraoxon hydrolysis reaction catalysis is 0.75 micro-mol / L.min, and the Km is 2.5 mmol / L. The polymer has the potential application value for constructing biometric sensors for degrading organophosphorus poison and detecting organophosphorus.

An organophosphorus compound degradation and detection integrated method based on an organic framework (MOF-808) composite material formed by Fe-doped carbon dots (Fe-CDs) and metal zirconium mainly comprises the following steps: forming an Fe-CDs / MOF-808 composite material with Fe-CDs embedded in pores of the MOF-808 and Fe-CDs@MOF-808 composite material with Fe-CDs attached to the surface of the MOF-808 in two modes. The two can degrade the organophosphorus compound to generate p-nitrophenol, fluorescence of Fe-CDs is quenched through the inner filtering effect, and degradation detection of the organophosphorus compound is achieved. The Fe-CDs / MOF-808 is characterized in that the MOF-808 catalyzes the hydrolysis of paraoxon under the condition of room temperature to generate p-nitrophenol; and the Fe-CDs@MOF-808 generates p-nitrophenol by photocatalytic degradation of parathion through generated <1> O2, .O2<-> and other active oxygen species under the illumination condition by utilizing the photosensitive oxidation performance of Fe-CDs. The method is high in organophosphorus pesticide degradation and detection speed, wide in detection linear range and low in detection limit, and can be applied to degradation and detection of organophosphorus compounds in actual water samples and fruit and vegetable samples.

The invention discloses a method for detecting enzymatic activity of PON-1 in a blood sample and application thereof. The method comprises the following steps: (a) taking paraoxon as a substrate, and detecting the activity of paraoxonase-1, PON-1 in a blood serum or blood plasma sample; (b) detecting the apolipoprotein AI (apo AI) level in the sample by immunity transmission turbidity; (c) calculating the ratio of the activity of the PON-1 to the apo AI level; and (d) comparing the calculated ratio with at least one known index indicating existence or inexistence of coronary heart disease. The method specifically and sensitively evaluates the existence of fatalness of the coronary heart disease by reflecting the relative activity of the PON-1 in HDL particles. The detection of the enzymatic activity is applied in preparing medicaments for treating or preventing cardiovascular and cerebrovascular diseases such as the coronary heart disease, miocardial infarction and the like. The PON-1 is a characteristic antioxidant enzyme having main antioxidant function in the HDL, and the activity thereof can reflect the antioxidant function of the HDL, so activity detection of the PON-1 is taken as a method and a tool for evaluating the fatalness of the coronary heart disease.

The invention belongs to the technical field of pesticide residue detection, and discloses a Ce-N-C nano-enzyme and application thereof in organophosphorus pesticide residue detection. The Ce-N-C nano enzyme has biomimetic hydrolase activity. According to the synthesis method of the Ce-N-C nano-enzyme, glucose and dicyanodiamine are taken as precursors, Ce (SO4) 2.4 H2O is added, so that a reaction can be performed to obtain a reaction product, high-temperature pyrolysis is carried out on the reaction product to prepare the Ce-N-C nano-enzyme. The Ce-N-C nano-enzyme is applied to detection of paraoxon of an organophosphorus pesticide. The preparation method of the Ce-N-C nano-enzyme is simple; and hydrolysis and rapid detection of the Ce-N-C on the paraoxon of the organophosphorus pesticidecan be completed.

The invention provides a cobalt nickel bimetal sulfide organophosphorus pesticide biosensor, and a preparation method thereof. The cobalt nickel bimetal sulfide organophosphorus pesticide biosensor comprises a carbon paste electrode and an acetylcholinesterase layer; the surface of the carbon paste electrode is provided with modification layers including a Nafion-NiCo2S4 layer, the acetylcholinesterase layer, and a Nafion layer form interior to exterior successively. A preparation method of NiCo2S4 comprises following steps: a soluble nickel salt and a soluble cobalt salt are dissolved in an ethanediol solution containing a cationic surface active agent, and a cobalt nickel bimetal sulfide is prepared via solvothermal method. The cobalt nickel bimetal sulfide organophosphorus pesticide biosensor possesses excellent enzyme immobilization performance, is high in sensitivity and stability; immobilization of acetylcholinesterase on the surface of the carbon paste electrode is realized so as to construct the cobalt nickel bimetal sulfide organophosphorus pesticide biosensor; and the cobalt nickel bimetal sulfide organophosphorus pesticide biosensor can be applied in detection on parathion-methyl and paraoxon-methyl.

The invention provides a method for detecting an organophosphorus pesticide (OP) by a flora-based sensing system. The sensing system comprises an OPH signal sensing module and a genetic engineering flora containing a signal generating module. One of the modules is used to hydrolyze OPs into p-nitrophenol (PNP), and the other one converts a PNP signal into beta-galactosidase generation for colorimetric detection. Through optimization, the sensing system can detect ethyl paraoxon at a concentration of 1*10<-9>M within 3.5 hours of induction at 28 DEG C, and is about 200 times more sensitive thana single-cell whole-cell sensor. In addition, the sensing system can detect various types of OPs commonly used in agriculture. Besides, the sensing system can be prepared into filter paper for detection of organophosphorus pesticides, showing the prospect of portable on-site detection. The invention provides a sensitive, fast and portable biological sensing platform for pollutant detection, and also shows a practical novel environmental application of an engineering microbial ecosystem.

The invention relates to a quartz crystal microbalance (QCM) ethyl paraoxon flow detection device which comprises a specific QCM sensor and a reference QCM sensor which are arranged in a flow detection pool, wherein output ends of the two sensors are sequentially connected with an input end of a differential frequency circuit through an oscillating circuit and a shaping circuit; and the output end of the differential frequency circuit communicates with an upper computer through a frequency measurement and communication circuit. The device is high in sensitivity, high in degree of automation, simple in structure and convenient to operate; according to introduction of the reference QCM sensor, the influence of liquid viscosity, density and other factors on the detection result is eliminated, and the interference resistance is improved; and through utilizing the high specific adsorption capacity of the specific QCM sensor on the ethyl paraoxon, the device is hardly interfered by other similar substances, and therefore, the selectivity is improved.

The invention discloses organophosphorus anhydrase as well as a coding gene and application thereof. The recombinant organophosphorus anhydrase to be protected in the invention is recombinant organophosphorus anhydrase OPAA1 or OPAA2. The amino acid sequence of the OPAA1 is a protein of a sequence 2 in a sequence table or a protein having more than 80% of identity with the protein of the sequence 2; and the amino acid sequence of the OPAA2 is a protein shown as a sequence 4 in a sequence table or a protein having more than 80% of identity with the protein shown as the sequence 4. The recombinant organophosphorus anhydrase prepared and expressed by the invention is soluble and easy to purify, and can degrade dipeptide with proline at the C end, organophosphorus pesticide paraoxon, especially phosphorus S and malathion absorbed by PS-containing organophosphorus pesticide, which are not reported before. The OPAA1 has a wide application prospect in the aspects of organophosphorus pesticide degradation and ecological restoration and in the aspect of green decontamination.

The invention discloses a method for selectively detecting organophosphorus pesticides in food based on an orange carbon dot fluorescence method. In the invention, the orange fluorescence emission CDs is used as an amplification detection signal, so that the influence of the fluorescence of the food matrix can be overcome, the background interference is effectively blocked, and the detection reliability is improved; coOOH NFs is used as a fluorescence quencher and can be used for efficiently quenching CDs fluorescence; the fluorescent response of the system is regulated and controlled by combining the mechanism that acetylcholin esterase (AChE) specifically catalyzes thioacetylcholine to inhibit the fluorescence quenching effect of CoOOH NFs and organophosphorus OPs specifically inhibits the activity of AChE, paraoxon can be rapidly detected, and the detection limit is 0.03 ngmL <-1 >. A fluorescence detection system constructed by the method is combined with a hydrogel kit, and a portable platform for quickly monitoring oxygen and phosphorus on site is prepared by utilizing a high-definition camera shooting function of a smart phone, so that a new visual angle is provided for accurately monitoring food safety on site.

The invention discloses a preparation method of a hydrogel kit for monitoring degradation of organophosphorus pesticides. The fluorescent composite material is embedded into a sodium alginate hydrogel system in a microwell plate to serve as a signal indicator, and the gel kit is prepared. A ratio fluorescence method is constructed by utilizing the fluorescence characteristic of AuNCs in the composite material and the oxidase-like activity of MnO2 nanosheets on OPD. According to the present invention, with the combination of the oxidation reduction reaction of the AChE enzymatic product TCh and the MnO2 nanosheet and the efficient inhibition effect of the pesticide on AChE, the organophosphorus pesticide degradation timely monitoring (POC) hydrogel kit is ingeniously constructed, and the color information is converted into the pesticide concentration information by using the smart phone software so as to be used for the accurate monitoring of the oxygen and phosphorus residue and degradation in the Chinese cabbage. According to the ratio type hydrogel kit developed by the invention, the sensing process is simplified, the sensing efficiency and sensitivity are greatly improved, a new method is created for organophosphorus pesticide detection, and a technical support is provided for application of a POC technology in food safety monitoring.

The invention provides functional monomers used for catalytic degradation of organophosphate and a preparation method of porous imprinted polymer, and relates to the fields of functional monomer design and synthesis of porous imprinted crosslinked polymers. The preparation method of the porous imprinted polymer of the functional monomers used for catalytic degradation of the organic phosphate comprises the following steps: synthesis of the functional monomers, preparation of a functional complex, and preparation of the porous imprinted polymer, wherein the main step is that the functional monomers simulating an enzymatic hydrolysis action mechanism of the phosphate are firstly synthesized, then the functional monomers and a metal salt are subjected to coordination to prepare the functionalcomplex, finally template molecules, a crosslinking agent and an initiator are added, uniform mixing is performed, and therefore the porous imprinted polymer is prepared under solvothermal conditions. According to the method provided by the invention, the organophosphate, such as paraoxon, parathion, chlorpyrifos, dichlorvos and bis(4-nitrophenyl) phosphate is used as a template, and the porous imprinted polymer having catalytic degradation functions on the organophosphorus compounds is prepared by a solvothermal method..

The invention provides a hydroxyl-containing microporous organic polymer organophosphorus pesticide biosensor and a preparation method thereof. The biosensor comprises a carbon paste electrode, an acetylcholin esterase layer and a Nafion layer, and modified layers on the surface of the carbon paste electrode are sequentially a Hy-MOP layer, an acetylcholin esterase layer and a Nafion layer from inside to outside. The biosensor provided by the invention has better enzyme immobilization capability and good biocompatibility and has higher sensitivity and stability. Hy-MOP suspension, AChE solution and Nafion solution are sequentially fixed on the carbon paste electrode, so that the organophosphorus pesticide biosensor is constructed. The biosensor provided by the invention can be used for detection on methyl parathion and paraoxon and is low in cost, easy to operate, high in sensitivity and good in selectivity, and linear detection ranges of the methyl parathion and paraoxon are respectively 5.0*10<-13>-1.0*10<-8>g / mL and 1.0*10<-13>-1.0*10<-9>g / mL.

The invention discloses an on-site quantitative organophosphorus pesticide detection platform based on integration of target response type hydrogel and a smart phone, and belongs to the technical field of biosensors. A hydrogel material with target response serves as a carrier, has MnO2NFs similar to oxidase activity, can oxidize a colorless 3, 3', 5-, 5'-tetramethylbenzidine color developing agent into blue oxTMB, and can decompose MnO2NFs in the presence of H2O2 to lose enzyme-like activity. The organophosphorus pesticide (paraoxon) serving as an inhibitor of AChE can inhibit AChE from catalyzing acetylcholine to generate H2O2 and reduce decomposition of MnO2NFs, so that color response of a kit is stimulated, and collection and analysis of image data of the kit are further realized in combination with the smart phone. The OPs can be rapidly detected in a handheld mode on site, the method has the advantages of being easy and convenient to operate, high in sensitivity, low in cost andthe like, and a new perspective is provided for portable monitoring of food safety and human health.

The invention belongs to the technical field of analytical chemistry, and relates to a method for detecting pesticide residues based on ratio fluorescence and colorimetric dual modes of ACP (at) Ce / Tb-IPA, which comprises the following steps: adding 50 [mu] L of 1mg / mL ACP (at) Ce / Tb-IPA dispersion liquid into a centrifuge tube, adding organophosphorus pesticide paraoxon with different concentrations, and incubating for 30 min; continuously adding 930 [mu] L of a NaAc-HAc solution and 20 [mu] L of an AAP solution, measuring fluorescence, and drawing a standard working curve taking the paraoxon concentration as a horizontal coordinate and the emission wavelength intensity ratio at 496 nm to 358 nm as a vertical coordinate; adding 30 [mu] L of a TMB solution into the mixed system, measuring the absorbance, and drawing a standard working curve with the paraoxon concentration as the abscissa and the absorbance at 652 nm as the ordinate; after the sample to be detected is treated in the same way, the detected numerical value is compared with the working curve, and the concentration can be obtained. According to the present invention, by using the specific triggering inhibition of the ACP activity and the potential influence of the by-product on the ACP (at) Ce / Tb-IPA oxidase and the luminescence characteristic, the dual-mode indirect detection of the pesticide residue is achieved, and the huge application potential is provided in the field of the pesticide residue detection.

The invention provides a mutant of an organophosphorus hydrolase, an expression vector, a recombinant bacterium and an application of the recombinant bacterium, and belongs to the technical field of genetic engineering and enzymology. According to the mutant, isoleucine at a 274th position of organophosphorus hydrolase mutates into asparagin. Compared with organophosphorus hydrolase, the providedmutant of the organophosphorus hydrolase improves the hydrolysis rate of paraoxon compounds.

The invention discloses a preparation method of phosphorus-containing flame-retardant polyether polyol, which comprises the following steps: (1) adding trimethylol phosphine and KOH into a stainless steel reaction kettle, and replacing the air in the reaction kettle with inert gas for 3 times , then raise the temperature to 80°C and keep it warm for 0.5‑1.5h; (2) Add propylene oxide to the product of step (1), then raise the temperature to 110°C and keep the pressure at 0.2‑0.6Mpa; (3) Release the pressure of the reactor , add phosphoric acid and N,N-dimethylcyclohexylamine to the product of step (2) in sequence, then vacuum dehydrate for 2 hours, filter, and filter the residue for later use; (4) disperse the obtained filter residue in water, and ultrasonically disperse it; (5 ) The product of step (4) was subjected to microwave reaction, and then suction filtered. According to the method provided by the invention, the obtained phosphorus-containing flame-retardant polyether polyol has high flame-retardant performance, the oxygen index can reach about 25%, and the mechanical performance is good.

The invention discloses a method for preparing molecularly imprinted polymer microspheres of organophosphorus hydrolysis simulating enzymes. The paraoxon transition state analogue (4-nitrobenzyl) diethyl phosphate is used as a template molecule, and 1-vinylimidazole 1. Methacrylic acid is the functional monomer, and molecular imprinting technology is used to prepare molecularly imprinted polymer microspheres with good dispersion and uniform particle size of organophosphorus hydrolysis imitating enzymes by precipitation polymerization. Compared with the spontaneous hydrolysis of paraoxon, the paraoxon hydrolase activity of the molecularly imprinted polymer microspheres prepared by the present invention can increase the hydrolysis efficiency by a maximum of 188 times, which is higher than that of the non-imprinted polymer synthesized under the condition of no template molecules. Also improved by a factor of 2.3, the measured K m and V max The values ​​are 0.064mmol / L·min and 2.41mmol / L respectively, K cat 0.237S -1 . The organophosphorus hydrolysis mimetic enzyme molecularly imprinted polymer microspheres prepared by the invention can be used not only for the efficient degradation of organophosphorus pesticides, but also for the degradation and destruction of organophosphorus nerve agent chemical weapons.

The invention relates to a production method of a vegetable hotpot condiment. According to the technical scheme, the method includes: taking the liver of cattle or pig of 1-2 years old, removing tendons and membranes, chopping, taking 5g of the chopped liver, adding 25ml of distilled water, and homogenizing to obtain enzyme liquid; placing 20ml of 0.1mol / L hydrochloric acid and 25ml of 0.2mol / L 3-hydroxy methyl-amino methane fs buffer solution into a 100ml volumetric flask; during color development, processing an unfolded thin plate in bromine steam to allow parathion and phoxim to become oxidized homologues (for example, the parathion becomes paraoxon, and the phoxim becomes phoxim oxon), and using nitrogen flow to completely volatilize the bromine steam; using a buffer solution to prepare an accurate-calibration-value pesticide into pesticides of different concentrations, and determining the detection limit of the pesticides; simultaneously using a gas chromatograph and an enzyme inhibition method to detect fruits and vegetables on the market, wherein results show that the sensitivity of the enzyme inhibition method is 100-1000 times higher than that of the gas chromatograph. Themethod is simple, low in cost, simple to operate and capable of fast and accurately detecting organophosphorus pesticide residues in the fruits and vegetables.

The invention provides a method for detecting an organophosphorus pesticide (OP) by a flora-based sensing system. The sensing system comprises an OPH signal sensing module and a genetic engineering flora containing a signal generating module. One of the modules is used to hydrolyze OPs into p-nitrophenol (PNP), and the other one converts a PNP signal into beta-galactosidase generation for colorimetric detection. Through optimization, the sensing system can detect ethyl paraoxon at a concentration of 1*10<-9>M within 3.5 hours of induction at 28 DEG C, and is about 200 times more sensitive thana single-cell whole-cell sensor. In addition, the sensing system can detect various types of OPs commonly used in agriculture. Besides, the sensing system can be prepared into filter paper for detection of organophosphorus pesticides, showing the prospect of portable on-site detection. The invention provides a sensitive, fast and portable biological sensing platform for pollutant detection, and also shows a practical novel environmental application of an engineering microbial ecosystem.

The invention relates to an organophosphorus hydrolase mutant and application thereof, and belongs to the technical field of genetic engineering and bio-enzymology. The mutant is characterized in that histidine at the 257th site of organophosphorus hydrolase is mutated into tyrosine, leucine at the 303rd site of the organophosphorus hydrolase is mutated into threonine, and the amino acid sequence of the organophosphorus hydrolase mutant is shown as SEQNO.1. The mutant effectively enhances the activity of the organophosphorus hydrolase and the ability of hydrolyzing a substrate, and when the mutant is used for degrading paraoxon compounds, the hydrolysis rate of the paraoxon compounds is effectively increased.

An on-site quantitative detection platform for organophosphorus pesticides based on target-responsive hydrogel and smart phone integration belongs to the technical field of biosensors. The carrier is a target-responsive hydrogel material with MnO-like oxidase activity 2 NFs, which can oxidize the colorless 3,3’,5-,5’-tetramethylbenzidine chromogen into blue oxTMB, and H 2 o 2 The presence of will decompose MnO 2 NFs make it lose its enzyme-like activity. Organophosphorus pesticide (paraoxon) as an inhibitor of AChE can inhibit AChE from catalyzing acetylcholine to generate H 2 o 2 , reducing MnO 2 The decomposition of NFs stimulates the color response of the kit, and further combines with the smartphone to realize the collection and analysis of the image data of the kit. The invention can quickly carry out on-site hand-held detection of OPs, has the advantages of simple operation, high sensitivity, low cost, etc., and provides a new perspective for portable monitoring of food safety and human health.

The invention discloses a method for detecting organophosphorus pesticides and nitrates. An organophosphorus pesticide rapid detection method based on a silver electrode is established through organophosphorus pesticide rapid detection combining an electrochemical method and an acetylcholinesterase inhibition method. Firstly, a cyclic voltammetry method and a current-time curve method are adopted;the property of the enzymatic reaction product thiocholine is studied, it is found that the silver electrode can generate specific response to thiocholine, electrode passivation and interference areavoided, and real-time monitoring of enzyme activity and pesticide detection are achieved. Linear response range of the silver electrode to thiocholine is 5.2 * 10 <-> 7 to 2.5 * 10<->5 mol / L, whereinthe detection limit of the organophosphorus pesticide (paraoxon) is 6.2 ppb, and the detection recovery rates of the Chinese cabbage and apple samples are 92.05% and 106.11% respectively, so that thesilver electrode is suitable for detecting pesticide residues in agricultural products. And then, a disposable silver electrode is prepared by using a screen printing technology, and the false negative problem of P = S type organophosphorus pesticide detection is solved. The method disclosed by the invention can be used for wearable equipment or directly writing on a monitored object to realize real-time monitoring of tiny angle change, limb actions and even plant behaviors.

The invention discloses a metal-organic coordination polymer with the organophosphorus hydrolase activity and a preparation method and application thereof. The structural unit of the polymer is [Zn(L1)0.5(L2)0.5].3DMF, wherein L1 represents 1,3-bis[di(2-diazole)-hydroxymethyl]phenyl, L2 represents 3,3',5,5'-biphenyl tetracarboxylic acid ions containing four carboxyls with no proton, DMF represents N,N-dimethyl formamide, and two DMF solvent molecules are out of order. The polymer belongs to a monoclinic system and a C2 / c space group. The polymer is synthesized under the low temperature through a solvothermal method, substrate organophosphorus can be effectively hydrolyzed, when pH is equal to 9.0, the ethyl paraoxon hydrolysis activity of the 0.1 mg / mL polymer is about 28 times the hydrolysis activity with no polymer, the Vmax of ethyl paraoxon hydrolysis reaction catalysis is 0.75 micro-mol / L.min, and the Km is 2.5 mmol / L. The polymer has the potential application value for constructing biometric sensors for degrading organophosphorus poison and detecting organophosphorus.

A ratio sensing detection method based on the activity of a CeO2 imitated organic phosphorus hydrolase and the CeO2 imitated oxide enzyme is characterized by comprising the specific steps: 1, incubating paraoxon standard samples with different concentrations and cerium dioxide nano enzyme, centrifuging, taking out supernate, and detecting ultraviolet and visible absorption to obtain a p-nitrophenol signal A400; and 2, dissolving the precipitate obtained after centrifugation in the step 1 with an acetic acid buffer solution, and then taking the solution to react with the prepared TMB to measure ultraviolet and visible absorption so as to obtain the absorption peak A653 of the oxidation-state TMB. Finally, the signal of the p-nitrophenol is compared with the signal of the oxidation-state TMB. The sensing method is low in experiment cost, high in accuracy, high in selectivity and high in detection speed in the detection process, and therefore paraoxon can be rapidly and sensitively detected through the designed CeO2-based organophosphorus-imitated hydrolase and oxygenase-imitated activity ratio sensing detection method.

In one embodiment, a hydrogel-enzyme construct for performing high temperature enzymatic reaction on paraoxon, and / or for performing enzymatic reaction on paraoxon following exposure to high temperature, includes a hydrogel having multiple layers of poly(methacrylic acid) (PMAA) and a plurality of dPTE2 enzyme molecules. Individual dPTE2 enzyme molecules are embedded between adjacent PMAA layers and are covalently bonded with respective individual PMAA layers. The hydrogel-enzyme construct is capable of performing enzymatic reaction on the paraoxon when the paraoxon is exposed to the hydrogel-enzyme construct under a temperature condition of up to above 99° C. and below 100° C. or when the paraoxon is exposed to the hydrogel-enzyme construct after the hydrogel-enzyme construct has been heated to a temperature condition of up to 550° C., where the enzymatic reaction on the paraoxon by individual dPTE2 molecules embedded within the hydrogel occurs at a residual activity of between 20% and 100%.

The invention belongs to the technical field of pesticide residue detection, and discloses a Ce-N-C nanozyme and its application in the detection of organophosphorus pesticide residues. Described Ce-N-C nanometer enzyme has imitative hydrolase activity; And the synthetic method of described Ce-N-C nanometer enzyme is to take glucose and dicyandiamine as precursors, add Ce(SO4) 4 ) 2 ·4H 2 O reacts to obtain a reaction product, and the reaction product is pyrolyzed at high temperature to prepare a Ce-N-C nanozyme; the Ce-N-C nanozyme is applied to the detection of organophosphorus pesticide paraoxon. The Ce-N-C nanozyme preparation method is simple, and can complete the hydrolysis and rapid detection of the organophosphorus pesticide paraoxon by Ce-N-C.

The invention relates to the technical field of analytical chemistry detection, in particular to a method for rapidly detecting the total amount of paraoxon by ultraviolet spectrophotometry. The method comprises the following steps: S1, preparing a rapid hydrolysis reagent by using ultrapure water, and uniformly mixing; S2, adding the mixed solution in the step S1 into a centrifugal tube, adding paraoxon methyl and paraoxon ethyl into the centrifugal tube at the same time, and uniformly mixing; S3, taking 100 [mu] L of the mixed solution in the step S2, adding a proper amount of acetonitrile, uniformly mixing, and recording as a to-be-detected solution; and S4, preparing nitrophenol solutions with different concentrations, carrying out ultraviolet spectrophotometric detection, and drawing a standard curve according to a determination result. According to the method of the invention, the rapid hydrolysis reagent has the advantages of cheap raw materials, no pollution and environmental friendliness, is simple to prepare and convenient to use, and can effectively improve the hydrolysis efficiency and speed.