Search

CN-121114161-B - Electrochemical gas sensor for detecting linalool and preparation method thereof

CN121114161BCN 121114161 BCN121114161 BCN 121114161BCN-121114161-B

Abstract

The invention relates to the technical field of analysis and detection, in particular to an electrochemical gas sensor for detecting linalool and a preparation method thereof. The preparation method is that the electrode surface is modified with a molecular imprinting film-zeolite imidazole ester framework material-8-multi-wall carbon nano tube-zinc oxide (MIP-ZIF-8-MWCNT-ZnO) composite material. The electrochemical gas sensor can sensitively and accurately detect the content of linalool gas released by plants, and realizes stable and accurate detection of linalool with high specificity and high sensitivity in complex environments. The technology can be used for early finding plant diseases and preventing infection transmission of the diseases, resists crop loss, and has wide application prospect.

Inventors

  • LUO BIN
  • LI AIXUE
  • HE YINING
  • YU WENXIN
  • JIN XIAOTONG
  • CHEN QUAN

Assignees

  • 北京市农林科学院智能装备技术研究中心

Dates

Publication Date
20260508
Application Date
20250812

Claims (16)

  1. 1. The preparation method of the electrochemical gas sensor for detecting linalool is characterized by comprising the steps of dispersing template molecular linalool in a polyvinyl alcohol solution, adding a cross-linking agent to prepare a molecular imprinting polymer, and removing the template molecular linalool to prepare MIP powder; dispersing multi-wall carbon nano tubes in a zeolite imidazole ester framework material-8 alcohol solution to prepare a ZIF-8-MWCNT solution, dispersing ZnO in the ZIF-8-MWCNT solution to prepare a ZIF-8-MWCNT-ZnO composite material; Dispersing MIP powder into ZIF-8-MWCNT-ZnO composite material to obtain MIP-ZIF-8-MWCNT-ZnO composite material, coating the MIP-ZIF-8-MWCNT-ZnO composite material on the surface of an electrode, and drying to obtain the electrochemical gas sensor for detecting linalool.
  2. 2. The preparation method according to claim 1, wherein the molar ratio of the template molecule linalool to the polyvinyl alcohol is 1 (1-5); And/or, in the mixture of linalool and polyvinyl alcohol solution, the concentration of linalool is 0.5-2 mM; and/or the polyvinyl alcohol solution is an aqueous solution of polyvinyl alcohol.
  3. 3. The method of claim 1 or 2, wherein the cross-linking agent is glutaraldehyde.
  4. 4. The method according to claim 3, wherein the molecular imprinted polymer is reacted at 80 ℃ to 90 ℃ after adding the crosslinking agent.
  5. 5. The preparation method according to claim 1 or 2, wherein the MIP powder is prepared by removing linalool which is a template molecule with an alcohol solvent.
  6. 6. The method according to claim 5, wherein the alcohol solvent is methanol.
  7. 7. The preparation method according to claim 1 or2, wherein the alcoholic solution of the zeolitic imidazolate framework material-8 is an alcoholic solution of the zeolitic imidazolate framework material-8.
  8. 8. The preparation method of claim 7, wherein in the zeolite imidazole skeleton material-8 alcohol solution, the concentration of the zeolite imidazole skeleton material-8 is 1-5 mg/mL, and the volume percentage concentration of the ethanol is 2% -10%.
  9. 9. The method according to claim 7, wherein the concentration of the multiwall carbon nanotubes is 0.1 to 0.5 mg/mL in the mixture of the multiwall carbon nanotubes and the zeolitic imidazolate framework material-8 in alcohol.
  10. 10. The method according to claim 7, wherein the concentration of ZnO in the mixture of ZnO and ZIF-8-MWCNT solution is 0.1 to 1 mg/mL.
  11. 11. The method according to claim 7, wherein the concentration of the MIP powder in the mixture of MIP powder and ZIF-8-MWCNT-ZnO composite is 0.1 to 2mg/mL.
  12. 12. The method of claim 1 or 2, wherein the electrode is an IDE electrode.
  13. 13. The method of claim 12, wherein the electrode is activated by potentiostatic means in sulfuric acid solution prior to use.
  14. 14. The electrochemical gas sensor for detecting linalool prepared by the preparation method according to any one of claims 1 to 13.
  15. 15. Use of the electrochemical gas sensor for detecting linalool according to claim 14, for detecting linalool, characterized in that it is in situ in vivo detection of linalool released by plants.
  16. 16. A method for in situ living body detection of linalool released from a plant body, comprising placing the electrochemical gas sensor according to claim 14 in a gas chamber and attaching the sensor to the surface of the plant body, and then connecting an electrochemical workstation for detection.

Description

Electrochemical gas sensor for detecting linalool and preparation method thereof Technical Field The invention relates to the technical field of analysis and detection, in particular to an electrochemical gas sensor for detecting linalool and a preparation method thereof. Background Linalool (Linalool) is a volatile monoterpene compound widely distributed in plants, and linalool with different concentrations exists in leaves, flowers, fruits and epidermal tissues of the plants. As a key component of plant secondary metabolites, linalool not only endows plants with unique fragrance (such as lavender and citrus plants), but also participates in physiological processes of plant insect resistance, pathogen inhibition, adverse stress response and the like. Linalool is reported to have antibacterial activity against staphylococcus aureus and escherichia coli. When a plant is infected by a pathogen, the plant releases more linalool. For example, in the case of the ash mold infected strawberries, the gas release amount of linalool was increased. Currently, the mainstream linalool detection methods include gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography-mass spectrometry (HPLC-MS), but these methods require destructive sampling (such as grinding and solvent extraction) of plant tissues, and are difficult to realize in-situ detection of living bodies. In addition, sample pretreatment steps are cumbersome (e.g., derivatization, solid phase extraction) and may lead to volatile linalool runaway or oxidative degradation, affecting the accuracy of quantification. In contrast, the electrochemical method has the advantages of high response speed, high sensitivity, good selectivity, wide detection range and the like, and has excellent application potential in the aspect of plant in-situ living body detection. Therefore, developing an electrochemical sensor capable of in situ living detection of linalool released from plants is a technical problem to be solved in the art. Disclosure of Invention In order to solve the technical problem, the invention provides a preparation method of an electrochemical gas sensor for detecting linalool, which comprises the steps of dispersing template molecular linalool in polyvinyl alcohol solution, adding a cross-linking agent to prepare molecularly imprinted polymer, and removing the template molecular linalool to prepare MIP powder; dispersing multi-wall carbon nano tubes in a zeolite imidazole ester framework material-8 alcohol solution to prepare a ZIF-8-MWCNT solution, dispersing ZnO in the ZIF-8-MWCNT solution to prepare a ZIF-8-MWCNT-ZnO composite material; Dispersing MIP powder into ZIF-8-MWCNT-ZnO composite material to obtain MIP-ZIF-8-MWCNT-ZnO composite material, coating the MIP-ZIF-8-MWCNT-ZnO composite material on the surface of an electrode, and drying to obtain the electrochemical gas sensor for detecting linalool. The MIP-ZIF-8-MWCNT-ZnO is a composite nano material consisting of MIP, ZIF-8, MWCNT and ZnO, the Molecular Imprinting (MIP) is molecular imprinting powder prepared by taking polyvinyl alcohol (PVA) as a functional monomer and linalool as a template molecule and adding a cross-linking agent, and after the template molecule is removed, a cavity with the same size and structure as the target molecule is formed on the MIP surface, so that linalool can be efficiently identified and combined. This is the first re-recognition of the target molecule. On the other hand, an important feature of zeolite imidazole framework-8 (ZIF-8) is that the flexibility of structure is created by the oscillation of the-CH-3 groups and the imidazole salt linker so that its microporous structure is adjustable (pore size about 3.4A), its pore size matches that of linalool molecules (molecular size about 5.2A), a size sieving effect can be achieved, preferential adsorption of linalool and elimination of macromolecular interferents (e.g., terpenes). And the imidazole ligand nitrogen-containing group of ZIF-8 can be combined with the hydroxyl and double bond of linalool through the actions of hydrogen bond, pi-pi accumulation and the like, so that the specific recognition of the sensor can be enhanced, and the selectivity of the sensor is further improved. The second recognition of the target molecule is achieved by ZIF-8. The high conductivity of multiwall carbon nanotubes (MWCNTs) enables them to rapidly transfer charge transfer signals induced by adsorbed molecules. Zinc oxide (ZnO) is used as a representative nanomaterial, has a wide band gap and excellent structural controllability, and is widely used in the field of gas sensing. ZnO is an n-type semiconductor, is sensitive to gas adsorption, and causes surface oxygen species change after linalool molecular adsorption, so that conductivity is obviously changed, and high-sensitivity response is realized. The sensor shows excellent sensitivity and selectivity through the catalytic effect and the dual rec