41 results about "DTNB" patented technology

The invention relates to a method for performing supersensitive detection on fungaltoxin of a DTNB mark-based gold@silver core-shell nanorod, and belongs to the technical fields of food safety, environment monitoring and the like. The gold nanorod is prepared by a seed growing method, 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB) is marked on the gold nanorod, meanwhile, the gold nanorod is coated with a silver shell layer to prepare a gold@DTNB@silver surface Raman enhanced substrate, a superparamagnetic magnetic material chitosan ferroferric oxide is prepared, a fungaltoxin aptamer complementary chain is coupled on the prepared Raman enhanced substrate, a fungaltoxin aptamer chain is coupled on the magnetic material, an enhancer and the magnetic material are combined and a Raman signal of a system is strongest when the fungaltoxin does not exist in the detection system, and the aptamer modified magnetic material is specifically and preferentially combined with the fungaltoxin and the Raman signal of the system is changed after an external magnetic field is separated when the fungaltoxin exists, so that the aim of quantitatively detecting the fungaltoxin is fulfilled.

The invention provides a surface-enhanced Raman detection method for mycotoxin based on a silica-coated gold nanotriangle. According to the method, a three-step seed induction method is employed for preparation of a gold nanotriangle, and the gold nanotriangle is labeled with a 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) signal molecule and coated with silica so as to prepare a gold@DTNB@silica surface Raman enhancing agent; a chitosan ferriferrous oxide (CS-Fe3O4) magnetic material is prepared at the same time; an enhanced substrate and the magnetic material are modified with mycotoxin aptamer so as to construct a mycotoxin detection system; when mycotoxin exists, gold@DTNB@silica and CS-Fe3O4 are bonded together via the effect of the specific recognition of the aptamer so as to form a CS-Fe3O4-aptamer-mycotoxin-gold@DTNB@silica detection system; with changes of the concentration of mycotoxin, the Raman signal of the system is not changed after magnetic separation; and thus, quantitative ultra-sensitive detection of mycotoxin in food is realized. The method is applicable to the technical fields of food safety, material chemistry and the like.

The invention relates to a kit for quickly detecting toxicity of pesticide residue, in particular to a kit for quickly detecting the toxicity of pesticide residue containing a mixture of acetylcholinesterase and butyryl cholinesterase. The kit consists of choline esterase, a substrate, a color-developing agent 5,5'-dithio-2-2'-dinitrobenzoic acid (DTNB) and phosphate buffer solution, wherein the choline esterase is the mixture containing the acetylcholinesterase and the butyryl cholinesterase, and the substrate contains butyrylthiocholine iodide.

The invention relates to a SERS-immunochromatography detection method for rapidly and highly sensitively detecting Mycoplasma pneumoniae infection. The detection principle is that Nitrocellulose membranes (NC) are used as a carrier, a double-layer dye 5,5'-dithiobis (2-nitrobenzoic acid){5,5'-dithiobis- (2-nitrozoic acid), DTNB} labeled Au@Ag nano material coupling detection antibody is used as anSERS probe, a novel surface enhanced Raman spectroscopy (SERS-ICA)-based immunochromatography technology is established by combining the traditional Immunochromatography assay (ICA), and the technology is used for detecting human IgM and Mycoplasma pneumoniae (MP) specific IgM positive serum samples. The detection comprises the processes of sample dilution, SERS probe release, antigen-antibody reaction, result analysis and the like. The SERS-immunochromatography detection method for rapidly and highly sensitively detecting Mycoplasma pneumoniae infection can improve the detection sensitivityof human IgM and the detection rate of the lung branch positive serum specimen, and has important significance for clinical treatment.

The invention provides a preparation method of Hainantoxin-III and belongs to the field of polypeptide and protein preparation. The Hainantoxin-III is synthesized with a Fmoc solid-phase peptide synthesis method, synthetic resin adopts Rink amide resin, cysteine in the second position and cysteine in the seventeenth position adopt Fmoc-Cys(Mmt)-OH, cysteine in other positions adopts Fmoc-Cys(Trt)-OH, Mnt protection removal is performed by adopting 3% TFA (trifluoroacetic acid) after polypeptide chain synthesis ends, disulfide bonds of cysteine in the second position and cysteine in the seventeenth position are formed with an air oxidation method, polypeptide is removed from the resin through pyrolysis after a first pair of disulfide bonds is formed, a second pair of disulfide bonds and a third pair of disulfide bonds are formed with a solid-phase DTNB (5,5'-Dithiobis-(2-nitrobenzoic acid)) oxidation method, and the Hainantoxin-III with biological activity is finally formed. The biological activity and the natural toxic activity of Hainantoxin-III prepared with the method are consistent, and the synthetic efficiency is high.

The basic method for determination of free carnitine and total carnitine in milk powder includes the following steps: (1) sample treatment, dissolving milk powder, using perchloric acid to precipitate milk fat and milk protein, adding water for constant volume, filtering and collecting filtrate for preparing sample solution; (2). sample solution and standard solution preparation; (3). determination reagent, including DTNB reagent, acetyl-Co A solution, carnitine transacetylase solution and DTNB working solution; and (4) colorimenation. Its method is simple and its detection result is accurateand reliable.

The invention discloses a urine detection kit for cervical cancer. The urine detection kit comprises a container 1 and a container 2, wherein the container 1 is used for accommodating 2 milliliters of DTNB solution, and the container 2 is used for accommodating 2 milliliters of phosphotungstic acid solution. The invention further discloses a using method of the kit. The using method comprises the following steps: receiving 1 milliliter of first morning urine of a subject, adding dropwise the first morning urine into the container with the DTNB solution, leaving the mixture to stand for 2 to 5 minutes, then adding the mixture into the container with the phosphotungstic acid solution, leaving the mixed solution to stand for 2 to 5 minutes, and observing whether the color of the mixed solution changes or not. According to the urine detection kit and the using method, whether the subject suffers from cervical cancer or not can be conveniently and rapidly judged by color development reaction.

The invention discloses a method for detecting pesticides residues in tea or tea leaves. A pesticide extraction reagent specially used for extracting residual pesticides in the tea leaves is developed against the special interference of endogenous substances in a tea or tea leaf sample to test, the pesticide residues in the tea leaves are extracted by using the reagent without adjustment of the pH value, chromatography column passing or an oxidation process, and the reagent has the advantages of safety, environmental protection and small use amount. Cholinesterase is initiatively compounded with DTNB to form an Et reagent, and the Et reagent and a sample solution to be detected directly undergo an enzyme inhibition reaction in the detection process to make the quantity of reagents added in the operation process be 1 lower than the variety quantity of reagents added in traditional operation processes, so the detection method is simple and reduces use of experiment apparatuses. The method is simple and fast, allows the full flow from sample processing to detection result reporting to be completed in 20min, and realizes multichannel simultaneous detection.

The invention discloses a double-layer Raman molecular marked silicon-core silver-shell composite nano label, a preparation method and immunochromatography application. The double-layer Raman molecular marked silicon-core silver-shell composite nano label sequentially comprises a SiO2 inner core, a PEI layer, a colloidal gold layer, a first DTNB layer, a nano Ag layer and a second DTNB layer frominside to outside, wherein the surface of the second DTNB layer is coupled with novel coronavirus recombinant antigen S proteins. The invention further discloses a preparation method of the compositenano-label and application of the composite nano-label in immunochromatographic detection. The composite nano-label can be used for simultaneously detecting anti-coronavirus IgM and IgG in a clinicalblood sample in a short time, has ultrahigh sensitivity, 100% accuracy degree, good dispersity, high stability and easy preparation on a large scale, and can be used for capturing, enriching and quickly detecting target substances in a complex sample system.

The invention provides a method for detecting a palladium ion based on a fluorescent carbon quantum dot. The method for detecting the palladium ion based on the fluorescent carbon quantum dot is characterized by the steps that step 1, distilled water and ethidene diamine with the volume ratio of 5 to (1-6) to 1 are mixed, 1mmoL DTNB (5,5'-double disulfide generation (2-nitrobenzoic acid)) is added, and ultrasonic processing is carried out for 10-15 min under the indoor temperature condition; step 2, a solution obtained in the step 1 is added into a high-pressure reaction kettle for carbonization, the temperature is arranged as 160-210 DEG C, the stirring speed is 350-400r/min, and the reaction time is 12-24h; and the step 3, a solution obtained in the step 2 is taken out, filtration and concentration are carried out, then gel column purification and filter liquor collection are carried out, concentration is carried out again, and drying is carried out to obtain a green fluorescent carbon quantum dot material. The method for detecting the palladium ion based on the fluorescent carbon quantum dot is simple and convenient to operate, an obtained probe can rapidly detect a Pd2+ion, andgood selectivity, sensitivity and reproducibility are achieved on the palladium ion. Meanwhile, it is found that other metal ions, heavy metal ions and amino acid substances have tiny interference onthe detection system.

The invention discloses a kit for detecting G119S mutation of culex acetylcholinesterase. The kit provided in the invention comprises a protein extracting solution, a developer, an inhibitor I, an inhibitor II and acetylthiocholine iodide. Specifically, the protein extracting solution is composed of a PB buffer solution and Triton X100 with a concentration of 1%; the developer is composed of a PB buffer solution, DTNB (5, 5'-Dithio-bis-2-nitrobenzoic acid) with a concentration of 0.2nM and NaHCO3 with a concentration of 0.35mM; the inhibitor I is composed of propoxur with a concentration of 10<-3>M and ethanol; the inhibitor II is composed of propoxur with a concentration of 10<-1>M and ethanol; a G119S mutant acetylcholinesterase coded gene is as shown in sequence 4 of a sequence table. The kit provided in the invention is simple to operate, and whether a mosquito has acetylcholinesterase G119 S mutation can be known only through visual inspection and color contrast. Being rapid and efficient, the kit of the invention can be used in fields and daily life, and provides guidance for people in terms of pesticide control to mosquitoes.

The invention discloses a method and a kit for rapidly detecting the drug resistance of a housefly to dimethyl dichloroviny phosphate (DDVP). Acetylcholinesterase (AChE) in the housefly is taken as a target of the DDVP, and can decompose a substrate acetylthiocholine (ATCh) iodide into an acetic acid and thiocholine iodide. The method specifically comprises the following steps of: performing color reaction of the thiocholine iodide and a sulphydryl color development agent 5,5-dithiobis(2-nitrobenzoic acid) (DTNB) to generate a yellow complex such as 5-mercapto-2-nitrobenzoic acid; when the AChE is not suppressed, namely the housefly is resistant, displaying yellow in the color reaction; and when the AChE is suppressed, namely the housefly is susceptible, displaying achromatic color in the color reaction. By the method and the kit, DDVP suppression concentration for distinguishing a susceptible strain from a resistant strain is made out by combining the activity, detected after the DDVP acts on the AChE, of the AChE in the housefly and a drug resistance level determined by housefly bioassay, and then the method for rapidly detecting the drug resistance of the housefly to the DDVP by utilizing a biochemiluminescence method is provided.

The invention discloses a determination method for cigarette smoke total particle phase induced cell oxidative stress GSH/GSSG. The determination method comprises the following steps that 1, an experiment reagent is prepared; 2, a cigarette smoke total particle phase object is prepared; 3, cell inoculation cultivation is conducted; 4, the contamination of the cigarette smoke total particle phase object is conducted; 5, sample treatment and GSH/GSSG determination are conducted; 6, result analysis is conducted. According to the determination method for the cigarette smoke total particle phase cell induced oxidative stress GSH/GSSG, an SBB buffer solution is used for re-suspending cells, artificial oxidation GSH is prevented, and meanwhile the effective processing time of a sample is increased; in consideration of the fact that protein of active sulfhydryl exists in a cell lysis solution, in order to reduce the situation that sulfide of non-glutathione is combined with DTNB to interfere determination, before sample determination, 5-sulfosalicylic acid is added to be used for removing the protein in the sample, and interference in the determination process is reduced; since the method determines the GSH and the GSSG at the same time, the minusing is used in the result treatment, the concentrations of the GSH and the GSSG can be obtained separately, and the determination method for the cigarette smoke total particle phase cell induced oxidative stress GSH/GSSG has the advantages of being short in time-consuming, simple and convenient to operate, high in sensitivity and reliable in results.

The invention belongs to the technical field of in-vitro diagnosis, and particularly relates to a urine sulfhydryl compound mercury-free detection test strip and a preparation method. The test strip comprises filter paper, and DTNB and EDTA which are loaded on the filter paper. The preparation method comprises the following steps: preparing a buffer solution, dissolving components needing to be loaded on the filter paper in the buffer solution, applying the mixed solution to the filter paper by a soaking method, cutting the filter paper into small blocks after the filter paper is dried, and pasting the small blocks on a plastic strip for later use. According to the technical scheme provided by the invention, DTNB is used as a sulfydryl color developing agent and is successfully improved into a test strip type urine detection reagent; the test strip does not contain heavy metal ions such as mercury and corrosive substances such as trichloroacetic acid, so that the use safety is improved, the detection rate is greatly increased and is shortened from at least 15 minutes to within 5 minutes, and the problem of the requirement of test strip detection on the color development time is solved.

The invention relates to the technical field of biomedical science detection, and discloses a construction method of a living cell probe based on neutrophilic granulocyte. The construction method comprises the steps of: A, performing BSA reduction; B, synthesizing Gd loaded BSA nanoparticles; C, labeling the Gd loaded BSA nanoparticles with Bodipy; and D, constructing a neutrophilic granulocyte probe: firstly with PBS as a medium, adding DTNB to a product solution in the step C, performing interaction at room temperature for a certain time to finish activation of BSA nanoparticles, after ultrafiltration and purification are performed, diluting the activated BSA nanoparticles to 0.1mg mL<-1> with an RPMI 1640 culture medium without FBS, then performing incubation with 1.25*10<6>cells.mL<-1>of neutrophilic granulocyte at room temperature, and then performing washing with ice-cold PBS so as to obtain the neutrophilic granulocyte probe.

The invention discloses a novel coronavirus detection kit and a preparation method thereof. Belongs to the technical field of medical examination. Comprising an immunochromatography surface enhanced Raman spectrum test strip for detecting the new crown virus and a sample extracting solution, and the test strip specifically comprises a Wu-DTNB (at) Ag-Ab1 solution uniformly coated on a combination pad, a new crown N protein antibody 2 coated on a nitrocellulose membrane to form a detection line, and rabbit anti-mouse IgG coated on the nitrocellulose membrane to form a quality control line. The test strip comprises a sample pad, a combination pad, a nitrocellulose membrane, a water absorption pad and a PVC backing, and the sample pad, the combination pad, the nitrocellulose membrane and the water absorption pad are sequentially and continuously adhered to the PVC backing. The kit has the advantages of strong specificity, high sensitivity, short detection time, on-site operation, low detection cost, simplicity and convenience in operation and the like.

The invention discloses a detection tube for detecting the content of hydrogen in water and an application of the detection tube and belongs to the field of enzymatic analysis in the technical field of biology. A tube body of the detection tube is a transparent cylinder; one end of the tube body is open and is provided with a sealing cover; acetylcholin esterase, a substrate, a color developing agent and powder of buffer substances are arranged at the bottom of the transparent detection tube; a mass ratio of the acetylcholin esterase to acetylthiocholine is 1:(200-300); a ratio of the acetylthiocholine to the color developing agent DTNB is (1:1)-(1:5); according to the buffer substances, the pH value of the liquid system is 6-8. The application method comprises the following steps: taking hydrogen water and deionized water of different concentrations as solvents, taking the deionized water, respectively adding hydrogen water with different concentrations, as solvents, and deionized water as reference, into centrifuge tubes, standing for 1 minute, observing the color of the reaction solution, and contrasting, wherein the color of the reaction solution is more luminous yellow than a solution treated by the deionized water, and the hydrogen water exists in the sample water; or, performing detection at the visible light absorption value of 412nm, and due to comparison of the deionized water, the higher the absorption value is, the higher the content of the hydrogen in the hydrogen water is.

The invention relates to a method for detecting the activity of benzyl alcohol acetyltransferase. According to the method provided by the invention, a reaction mechanism that DTNB (5,5'-dithiobis-(2-nitrobenzoic acid) can have a mutual effect with sulfydryl to form colored thiophenol anions; the activity of the benzyl alcohol acetyltransferase in a protein sample is determined through detecting the generation amount of the sulfydryl in a reaction product. The method provided by the invention has the advantages that experiment operation steps are simple, the dosage of the sample is relatively less and a detection result is sensitive and accurate. When the method provided by the invention is applied, the efficient benzyl alcohol acetyltransferase can be relatively easily screened from different protein samples.