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CN-121972160-A - Octahedral Ag2O nano enzyme preparation method and colorimetric method for detecting H2O2Is a method of (2)

CN121972160ACN 121972160 ACN121972160 ACN 121972160ACN-121972160-A

Abstract

The embodiment of the disclosure provides a preparation method of octahedral Ag 2 O nano enzyme and a method for detecting H 2 O 2 by a colorimetric method, and relates to the technical field of H 2 O 2 detection. The colorimetric method for detecting H 2 O 2 comprises the steps of S11, taking a plurality of centrifuge tubes, adding quantitative A g2 O solution and H 2 O 2 with different concentrations into each centrifuge tube, uniformly mixing, S12, adding NaAc-Hac buffer solution and TMB solution into each centrifuge tube processed in the step S11 to form an Ag 2 O-TMB-H 2 O 2 reaction system, heating the Ag 2 O-TMB-H 2 O 2 reaction system in each centrifuge tube in a water bath for a preset time, observing the change of the color of the solution in each centrifuge tube, and S13, measuring the absorbance value of the Ag 2 O-TMB-H 2 O 2 reaction system at the preset wavelength by an ultraviolet photometer and recording data. The colorimetric method for detecting H 2 O 2 has the advantages of simple operation process, accurate detection, visual result and the like.

Inventors

  • CHEN GUOZHEN
  • LEI JING
  • YUE ZHIYONG
  • WANG JINPEI
  • ZHAO DONG
  • CHEN LING

Assignees

  • 西安外事学院

Dates

Publication Date
20260505
Application Date
20251217

Claims (9)

  1. 1. A method for preparing octahedral a g2 O nanoenzyme, which is characterized by comprising the following steps: s1, preparing a nitric acid solution, an ammonia water solution and a sodium hydroxide solution; Step S2, slowly dripping the ammonia water solution into the nitric acid solution to form silver ammonia solution, stirring for a preset time, dripping the sodium hydroxide solution into the mixture while stirring to form a large amount of brown precipitate, and collecting and washing the precipitate after the precipitate is left in the solution for a preset time to obtain octahedral Ag 2 O nano enzyme powder; S3, characterizing the Ag 2 O nano enzyme powder by utilizing X-ray diffraction; and S4, characterizing the morphology and the size of the Ag 2 O nano enzyme powder by using a scanning electron microscope.
  2. 2. The method according to claim 1, wherein, in step S1, The preparation of silver nitrate solution comprises weighing 0.8494 g silver nitrate, placing in beaker, adding 45 mL pure water, stirring to dissolve thoroughly, transferring the silver nitrate solution into 50 mL volumetric flask, fixing volume with rubber head dropper, and attaching label to obtain silver nitrate solution with concentration of 0.1 mol/L; Preparing an ammonia solution, namely sucking 376 mu L of 25% ammonia water, and adding enough pure water to dilute the ammonia water into a 50 mL volumetric flask to obtain the ammonia water solution with the concentration of 0.1 mol/L; Preparing sodium hydroxide solution comprises weighing 2.000 g sodium hydroxide, pouring into beaker, adding 20 mL pure water, stirring until sodium hydroxide is completely dissolved, transferring sodium hydroxide solution into 25 mL volumetric flask, fixing volume with rubber head dropper, and labeling to obtain sodium hydroxide solution with concentration of 2.0 mol/L.
  3. 3. The method according to claim 1, wherein, in step S2, 50 ML of 0.1 mol/L AgNO 3 solution is measured and placed in a beaker, 25 mL of 0.1 mol/L ammonia water is slowly dripped under the constant temperature magnetic stirring condition of 600 r/min to form silver ammonia solution through complexation, after stirring 10 min, 2.5 mL of 2 mol/L NaOH solution is dripped into the mixture under stirring, after a large amount of brown precipitate is formed, the precipitate is left in the solution for 12 h, the precipitate is centrifuged for 25 min at the rotating speed of 8000 rpm, and the precipitate is collected and washed with ethanol and pure water until the pH value of the final aqueous solution is neutral, thus obtaining the octahedral Ag 2 O nano enzyme powder.
  4. 4. The method according to claim 1, wherein, in step S3, The octahedral Ag 2 O nano enzyme powder is scattered in a square frosted area of a glass slide and uniformly filled, and is characterized by X-ray diffraction after being flattened by a cover glass.
  5. 5. The method according to claim 4, wherein, in step S4, Fixing the conductive adhesive on a sample table, grinding the octahedral Ag 2 O nano enzyme powder into powder, then spot-coating the powder on the conductive adhesive, blowing and uniformly coating, then placing the powder on a scanning electron microscope for inspection, and taking a picture.
  6. 6. A method for colorimetrically detecting H 2 O 2 , said method comprising the steps of: Step S11, taking a plurality of centrifuge tubes, adding quantitative A g2 O solution and H 2 O 2 with different concentrations into each centrifuge tube, and uniformly mixing, wherein the A g2 O solution is prepared by the preparation method of the octahedral A g2 O nano enzyme according to any one of claims 1-5; step S12, adding NaAc-Hac buffer solution and TMB solution into each centrifuge tube processed in the step S11 to form an Ag 2 O-TMB-H 2 O 2 reaction system, heating the Ag 2 O-TMB-H 2 O 2 reaction system in each centrifuge tube in water bath for a preset time, and observing the color change of the solution in each centrifuge tube; and S13, measuring the absorbance value of the Ag 2 O-TMB-H 2 O 2 reaction system at a preset wavelength by an ultraviolet photometer and recording data.
  7. 7. The method of claim 6, wherein prior to performing step S12, the method further comprises formulating NaAc-Hac buffer and TMB solution, wherein, Preparing NaAc-Hac buffer solution, namely weighing 4.1017 g anhydrous sodium acetate, pouring the anhydrous sodium acetate into a container, adding 2.86 mL glacial acetic acid, and adding enough pure water to prepare 500 mL of 0.1 mol/L buffer solution; Preparing TMB solution comprises weighing 0.2500 g of 3,3', 5' -tetramethyl benzidine, placing in a container, adding 1.5 mL of absolute ethanol, heating and stirring continuously to dissolve completely, and metering to 25 mL volumetric flask to obtain 41.6 mmol/L TMB solution.
  8. 8. The method according to claim 6, characterized in that the method comprises: In the step S11, a plurality of 5mL centrifuge tubes are taken, 50 mu L of A g2 O solution and 20 mu L of H 2 O 2 with different concentrations are added into each centrifuge tube and mixed uniformly; In the step S12, after 3810 mu L of NaAc-Hac buffer solution with the pH value of 4.5 and 120 mu L of TMB solution with the concentration of 0.1 mol/L are added into each centrifuge tube treated in the step S11 to form an Ag 2 O-TMB-H 2 O 2 reaction system, and after the Ag 2 O-TMB-H 2 O 2 reaction system 50 min in each centrifuge tube is heated in a water bath at the temperature of 25 ℃, the color change of the solution in each centrifuge tube is observed visually; In step S13, the absorbance value of the Ag 2 O-TMB-H 2 O 2 reaction system at 652 nm wavelength was measured by a T2600 ultraviolet spectrophotometer and the data was recorded.
  9. 9. The method according to claim 6, further comprising the step of: S14, measuring 5 mL parts of liquid to be measured by using a measuring cylinder, placing the liquid to be measured in a 50 mL beaker, adding 45 mL of 0.1mol/L NaAc-HAc buffer solution, stirring and mixing uniformly, standing for 15min, centrifuging for 20 min parts of liquid at 8000 r/min, and taking supernatant as a solvent to prepare a labeled sample of H 2 O 2 ; S15, adding a labeled sample into NaAc-HAc buffer solution containing Ag 2 O nano-enzyme and TMB solution to form a reaction solution, wherein the concentration of the Ag 2 O nano-enzyme in the reaction solution is 125 mu mol/L, the concentration of the TMB in the reaction solution is 0.225 mmol/L, and the concentration of H 2 O 2 in the labeled sample is 5 mu mol/L, 10 mu mol/L and 50 mu mol/L respectively; After the solution 50 min treated in the step S15 was heated in a water bath at 25℃in the step S16, the absorption spectrum of the reaction solution at 652: 652 nm was measured by a T2600 ultraviolet spectrophotometer, and the data was recorded to calculate the recovery rate.

Description

Preparation method of octahedral Ag 2 O nano enzyme and method for detecting H 2O2 by colorimetric method Technical Field The disclosure relates to the technical field of analyte concentration detection, in particular to a preparation method of octahedral Ag 2 O nano enzyme and a method for detecting H 2O2 by a colorimetric method. Background H 2O2 is a green, common and high-quality chemical reagent widely applied to the fields of chemical industry, food, sanitation and the like, and has become a popular choice in the industry. H 2O2 can be used as a marker of serious diseases and also can be used as an additive in foods. When the concentration of H 2O2 entering the human body is too high, excessive hydroxyl radicals can be generated, and serious harm is caused to the health of the human body. The detection method of H 2O2 also comprises a chemical titration method, an electrochemical method and the like, but the methods have more professional requirements on operators, more strict experimental environments and more expensive needed instruments. Compared with the methods, the colorimetric detection of the peroxidase-like activity H 2O2 based on the nano-enzyme is more visual, rapid and low in cost. On the basis of the experimental object, a colorimetric sensor can be built for searching a novel nano enzyme to improve detection sensitivity, and the colorimetric sensor is tiled and has important significance for building a simpler, faster and accurate detection method for H 2O2. Disclosure of Invention The method for detecting H 2O2 by using the colorimetric method has the advantages of simple operation process, accurate detection, visual result and the like. According to a first aspect of embodiments of the present disclosure, there is provided a method for preparing octahedral Ag 2 O nanoenzyme, the method comprising the steps of: s1, preparing a nitric acid solution, an ammonia water solution and a sodium hydroxide solution; Step S2, slowly dripping the ammonia water solution into the nitric acid solution to form silver ammonia solution, stirring for a preset time, dripping the sodium hydroxide solution into the mixture while stirring to form a large amount of brown precipitate, and collecting and washing the precipitate after the precipitate is left in the solution for a preset time to obtain octahedral Ag 2 O nano enzyme powder; S3, characterizing the Ag 2 O nano enzyme powder by utilizing X-ray diffraction; and S4, characterizing the morphology and the size of the Ag 2 O nano enzyme powder by using a scanning electron microscope. In one embodiment, in step S1, The preparation of silver nitrate solution comprises weighing 0.8494 g silver nitrate, placing in beaker, adding 45 mL pure water, stirring to dissolve thoroughly, transferring the silver nitrate solution into 50 mL volumetric flask, fixing volume with rubber head dropper, and attaching label to obtain silver nitrate solution with concentration of 0.1 mol/L; Preparing an ammonia solution, namely sucking 376 mu L of 25% ammonia water, and adding enough pure water to dilute the ammonia water into a 50 mL volumetric flask to obtain the ammonia water solution with the concentration of 0.1 mol/L; Preparing sodium hydroxide solution comprises weighing 2.000 g sodium hydroxide, pouring into beaker, adding 20 mL pure water, stirring until sodium hydroxide is completely dissolved, transferring sodium hydroxide solution into 25 mL volumetric flask, fixing volume with rubber head dropper, and labeling to obtain sodium hydroxide solution with concentration of 2.0 mol/L. In one embodiment, in step S2, 50 ML of 0.1 mol/L AgNO 3 solution is measured and placed in a beaker, 25 mL of 0.1 mol/L ammonia water is slowly dripped under the constant temperature magnetic stirring condition of 600 r/min to form silver ammonia solution through complexation, after stirring 10 min, 2.5 mL of 2 mol/L NaOH solution is dripped into the mixture under stirring, after a large amount of brown precipitate is formed, the precipitate is left in the solution for 12 h, the precipitate is centrifuged for 25 min at the rotating speed of 8000 rpm, and the precipitate is collected and washed with ethanol and pure water until the pH value of the final aqueous solution is neutral, thus obtaining the octahedral Ag 2 O nano enzyme powder. In one embodiment, in step S3, The octahedral Ag 2 O nano enzyme powder is scattered in a square frosted area of a glass slide and uniformly filled, and is characterized by X-ray diffraction after being flattened by a cover glass. In one embodiment, in step S4, Fixing the conductive adhesive on a sample table, grinding the octahedral Ag 2 O nano enzyme powder into powder, then spot-coating the powder on the conductive adhesive, blowing and uniformly coating, then placing the powder on a scanning electron microscope for inspection, and taking a picture. According to a second aspect of embodiments of the present disclosure, there is provided a method of colorim