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CN-121718348-B - Fluorescent composite nano material for detecting formaldehyde and preparation method and application thereof

CN121718348BCN 121718348 BCN121718348 BCN 121718348BCN-121718348-B

Abstract

The invention discloses a fluorescent composite nanomaterial for detecting formaldehyde and a preparation method and application thereof, and belongs to the technical field of formaldehyde detection. The fluorescent composite nanomaterial is Cs 2 NaYF 6 @CDs@SiO 2 @MIP and has a multi-layer core-shell structure, and sequentially comprises a core layer, an up-conversion luminescent nanoparticle Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ , an intermediate modification layer, a protective and functional spacer layer, a specific recognition layer and a MIP layer, wherein the core layer is a CDs loaded on the surface of the core layer, the protective and functional spacer layer is an SiO 2 shell layer wrapped outside, the specific recognition layer is an aldehyde molecularly imprinted polymer shell layer, and the MIP layer is provided with imprinting holes complementary with formaldehyde molecules, so that the specific recognition and capture of formaldehyde can be realized. The fluorescent composite luminescent nanomaterial prepared by the invention can realize the specific detection of formaldehyde, and has high measurement stability and short response time.

Inventors

  • HUANG BINGQI
  • LIN XIAOHUI
  • LI YUEYANG
  • ZHANG WENCHANG
  • Li fengze
  • ZHANG ZHANCHANG
  • LIU GUOFENG
  • XU SHICAI
  • LI BINGWEN
  • WANG RUI
  • ZHANG JUNYE
  • QIAO MEI
  • LI CHONGHUI
  • LI ZHEN

Assignees

  • 德州学院

Dates

Publication Date
20260512
Application Date
20260210

Claims (8)

  1. 1. The fluorescent composite nanomaterial for detecting formaldehyde is characterized by being Cs 2 NaYF 6 @CDs@SiO 2 @MIP, having a multi-layer core-shell structure and sequentially comprising from inside to outside: A core layer, up-conversion luminescent nano-particles Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ ; An intermediate modification layer, namely CDs loaded on the surface of the nuclear layer; a protective and functional spacer layer, which is a SiO 2 shell layer wrapped outside; The specific recognition layer is a formaldehyde molecularly imprinted polymer shell layer, and the MIP layer is provided with imprinting holes complementary with formaldehyde molecules; The preparation method of CDs comprises mixing citric acid, water and ethanolamine, and performing solvothermal or hydrothermal reaction to obtain the final product; The dosage ratio of the citric acid, the water and the ethanolamine is (0.05-0.3 mol): (10-30 mL): (0.1-0.5 mol); the solvothermal or hydrothermal reaction condition is that the temperature is kept at 150-200 ℃ for 4-10 h; The Y element, the Yb element and the Tm element in the up-conversion luminescent nano-particles Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ are all selected from acetate, wherein the molar ratio of the acetate containing the Y element to the acetate containing the Yb element to the acetate containing the Tm element is (58-60): (39-41): 1; The morphology of the Cs 2 NaYF 6 @CDs@SiO 2 @MIP fluorescent composite nano material is spherical nano particles, and the size is 30-100 nm; CDs are dot-shaped nano particles with the size of 1-10 nm; The preparation method comprises the following steps: S1, preparing up-conversion luminescent nano particles Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ ; S2, (1) mixing Cs 2 NaYF 6 ：Yb 3+ /Tm 3+ chloroform dispersion liquid, a surfactant and a CDs solution to obtain UCNPs aqueous solution, and stabilizing at a set temperature; (2) Adding formaldehyde solution, alkali, silane coupling agent, silicon source and ethyl acetate into the stable UCNPs water solution, and heating for reaction; (3) And (3) adding a methanol/acetic acid mixed solution into the solution after the reaction in the step (2) to obtain the Cs 2 NaYF 6 @CDs@SiO 2 @MIP fluorescent composite nanomaterial.
  2. 2. The fluorescent composite nanomaterial for detecting formaldehyde according to claim 1, wherein the mass ratio of the up-conversion luminescent nanoparticles Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ to CDs is (43-50): 1.
  3. 3. A method for preparing the fluorescent composite nanomaterial for detecting formaldehyde according to claim 1 or 2, characterized by comprising the steps of: S1, preparing up-conversion luminescent nano particles Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ ; S2, (1) mixing Cs 2 NaYF 6 ：Yb 3+ /Tm 3+ chloroform dispersion liquid, a surfactant and a CDs solution to obtain UCNPs aqueous solution, and stabilizing at a set temperature; (2) Adding formaldehyde solution, alkali, silane coupling agent, silicon source and ethyl acetate into the stable UCNPs water solution, and heating for reaction; (3) And (3) adding a methanol/acetic acid mixed solution into the solution after the reaction in the step (2) to obtain the Cs 2 NaYF 6 @CDs@SiO 2 @MIP fluorescent composite nanomaterial.
  4. 4. A method of preparation according to claim 3, wherein the surfactant comprises cetyltrimethylammonium bromide; The silane coupling agent comprises 3-aminopropyl triethoxysilane; The silicon source comprises silicate; The usage proportion of Cs 2 NaYF 6 ：Yb 3+ /Tm 3+ chloroform dispersion liquid, CDs solution, surfactant, formaldehyde solution, alkali, silane coupling agent, silicon source and ethyl acetate is (5-10 mL): (0.5-2 mL): (40-60 mg): (40-60 μL): (100-200 μL): (10-30 μL): (100-200 μL): (0.1-1 mL); The concentration of the Cs 2 NaYF 6 ：Yb 3+ /Tm 3+ chloroform dispersion is 0.01-0.1 mmol/mL; the volume ratio of the ethyl acetate to the methanol/acetic acid mixed solution is (0.1-1 mL) to (10-30 mL); The concentration of the alkali is 1-3 mol/L.
  5. 5. The method according to claim 3, wherein in the step (1), the UCNPs aqueous solution is stable at 60 to 80 ℃ for 5 to 15min; in the step (2), an oil bath heating mode is adopted, and the oil bath is carried out for 1-5 hours at 50-80 ℃; in the step (3), the volume ratio of the methanol to the acetic acid is (8-10): 1, and the centrifugation condition is 10000-15000 r/min for 10-30 min.
  6. 6. The method of claim 3, wherein the up-conversion luminescent nanoparticle Cs 2 NaYF 6 :Yb 3+ ,Tm 3+ is prepared by the following steps: (1) Mixing yttrium salt, ytterbium salt, thulium salt, oleic acid, octadecene and oleylamine, heating under protective gas, and stirring to form a precursor solution; (2) Dissolving sodium salt and cesium salt in an alcohol solvent, adding the sodium salt and cesium salt into a precursor solution, heating to a set temperature, and preserving heat to obtain a mixed solution; (3) Vacuumizing the mixed solution for a set time under a sealed environment, heating under a protective gas, and preserving heat to obtain a crude product solution; (4) Centrifuging, washing and purifying the crude product solution to obtain the product; the dosage ratio of yttrium salt, ytterbium salt, thulium salt, oleic acid, octadecene and oleylamine is (0.4-0.7 mmol): (0.2-0.6 mmol): (0.005-0.02 mmol): (12-20 mL): (12-2 0 ML), the dosage ratio of yttrium salt, cesium salt and sodium salt is (0.4-0.7 mmol): (8-12 mmol), the yttrium salt comprises Y (Ac) 3 ·4H 2 O, the ytterbium salt comprises Yb (Ac) 3 ·4H 2 O, the thulium salt comprises Tm (Ac) 3 ·4H 2 O, the sodium salt comprises Na (Ac). 3H 2 O, and the cesium salt comprises CsF; in the step (1), the protective gas comprises nitrogen, the heating temperature is 100-150 ℃, and the stirring time is 20-60 min; In the step (2), the alcohol solvent comprises methanol, the dosage ratio of sodium salt, cesium salt and the alcohol solvent is (8-12 mmol): (5-10 ml), the temperature is raised to 50-100 ℃, and the heat preservation time is 60-80 min; in the step (3), vacuumizing and maintaining for 10-30 min, and maintaining the heating temperature at 310-330 ℃ for 1-2 h.
  7. 7. The fluorescent composite nanomaterial for detecting formaldehyde according to claim 1 or 2 or the fluorescent composite nanomaterial for detecting formaldehyde prepared by the preparation method according to any one of claims 3 to 6, wherein the fluorescent composite nanomaterial for detecting formaldehyde is used for detecting formaldehyde.
  8. 8. The formaldehyde detection method is characterized in that the fluorescent composite nanomaterial for detecting formaldehyde prepared by the preparation method of any one of claims 1 or 2 or 3-6 is adopted, and the method comprises the following steps: and placing the fluorescent composite nano material for detecting formaldehyde in an environment containing formaldehyde, taking an excitation light source with the wavelength of 360-370 nm as excitation light, and detecting an emission spectrum.

Description

Fluorescent composite nano material for detecting formaldehyde and preparation method and application thereof Technical Field The invention belongs to the technical field of formaldehyde detection, and particularly relates to a fluorescent composite nanomaterial for detecting formaldehyde as well as a preparation method and application thereof. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. Formaldehyde is a colorless gas with strong pungent smell, has extremely strong volatility at normal temperature and normal pressure, is easily dissolved in solvents such as water, alcohols, ethers and the like, and the aqueous solution of the formaldehyde is commonly called formalin, so that liquid products with different concentrations can be prepared according to requirements in industrial production. Formaldehyde is used as an important organic chemical raw material and is widely applied to the fields of building materials, furniture manufacturing, textile printing and dyeing, medicines and the like. Formaldehyde can enter a human body through the ways of indoor air volatilization, industrial wastewater discharge, illegal food addition, decoration material release and the like, and long-term contact or ingestion can cause serious harm to the respiratory system, the nervous system and the immune system of the human body and even possibly induce cancers, so that the development of a simple, quick and sensitive detection method for enhancing the monitoring of formaldehyde is necessary. The current formaldehyde detection method mainly comprises high performance liquid chromatography, gas chromatography-mass spectrometry, spectrophotometry and the like. Although the methods can realize accurate detection of formaldehyde, expensive precise instruments are generally relied on, the operation flow is complex, and the analysis period is long. Taking high performance liquid chromatography as an example, the sample needs to be subjected to multi-step pretreatment such as derivatization reaction, n-hexane extraction and the like before detection, and the phenol reagent rule needs to be sent to a laboratory to complete color development and absorbance measurement after sampling, so that the requirements of on-site rapid detection are difficult to meet. There are also researches and reports on an electrochemical detection method, wherein the method realizes quantitative detection by carrying out electrochemical reaction on a sensitive material modified on the surface of an electrode and formaldehyde and establishing a concentration standard curve according to the change of redox current. However, the electrochemical detection method has the remarkable limitations that although the response speed is high, the stability of the sensor is extremely poor, the electrode catalyst is easy to age, and frequent calibration and maintenance are needed. The fluorescence detection method has the advantages of high response speed, strong environmental tolerance and portability of equipment, and becomes an ideal choice for field detection. However, the current field has obvious technical gap that the reported fluorescent materials are mostly single matrixes, are easily interfered by other volatile organic compounds in complex environments, and have insufficient long-term storage stability. Disclosure of Invention In order to solve the defects of the prior art, the invention aims to provide a fluorescent composite nano material for detecting formaldehyde, a preparation method and application thereof, the fluorescent composite nanomaterial for detecting formaldehyde provided by the invention has the advantages of strong fluorescence emission, high measurement accuracy and strong specificity, and can be used for accurately measuring formaldehyde within the range of 0-15 mg/L. The invention discloses a fluorescent composite nano material for detecting formaldehyde and a preparation method thereof, wherein the preparation method comprises the steps of preparing Cs 2NaYF6 nano particles (Cs 2NaYF6:Yb3+,Tm3+) doped with Yb 3+ and Tm 3+, uniformly mixing Cs 2NaYF6 nano particles doped with Yb 3+ and Tm 3+, CDs (carbon dots), a surfactant (cetyl trimethyl ammonium bromide), formaldehyde solution, alkali (sodium hydroxide), a silane coupling agent (3-aminopropyl triethoxysilane), silicate (tetraethyl silicate) and ethyl acetate in a solvent, stirring and heating for reaction, adding the reacted solution into a methanol/acetic acid mixed solution, continuously stirring for a set time, and centrifuging and washing to obtain the fluorescent composite nano material. The fluorescent composite luminescent nanomaterial prepared by the invention can realize specific detection of formaldehyde within