Preparation method and application of amorphous Cu-MOF
Amorphous Cu-MOFs were prepared by solvothermal method and ammonia etching, which solved the problem of efficient preparation of amorphous Cu-MOF materials and enabled their application in colorimetric sensors, especially for reliable detection of ampicillin and high-selectivity detection of thiram.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU MEDICAL UNIV
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-30
AI Technical Summary
In the current technology, the research on Cu-MOF materials mainly focuses on the crystalline field, while the research on amorphous Cu-MOF materials has not been in-depth, lacking efficient and low-cost preparation methods, and its application scenarios are limited.
Crystalline Cu-MOF was synthesized by a solvothermal method, and amorphous Cu-MOF was obtained by etching with ammonia water. It was then applied to the fabrication of a colorimetric sensor, and a highly selective colorimetric sensing system was constructed using thiram as a cofactor.
A simple and efficient preparation of amorphous Cu-MOF was achieved, which can reliably detect ampicillin under neutral conditions and significantly activate the catalytic function in the presence of thiram, thus constructing a highly selective colorimetric sensor.
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Figure CN122302310A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal-organic framework materials technology, and more specifically, to a method for preparing amorphous Cu-MOF and its applications. Background Technology
[0002] Metal-organic frameworks (MOFs), as a class of organic-inorganic hybrid crystalline materials formed by the self-assembly of metal central ions and organic ligands through coordination bonds, have shown broad application prospects in many fields such as gas adsorption and separation, catalysis, and drug delivery due to their unique structural advantages such as high porosity, low density, large specific surface area, regular channels and tunable pore size.
[0003] Amorphous MOF materials refer to a class of materials that do not possess a long-range ordered crystal structure, but whose metal ions and organic ligands still maintain coordination connections in the short range. Compared with crystalline MOFs, amorphous MOF materials have several unique advantages. First, the synthesis conditions of amorphous MOF materials are relatively mild, and there is no need to strictly control the crystal growth process, which makes their large-scale preparation easier and helps reduce production costs. Second, because amorphous MOF materials do not have a long-range ordered crystal structure, their internal active sites are more uniformly distributed and denser, providing more active centers for catalytic and other reactions, thus potentially exhibiting superior performance. In addition, amorphous MOF materials have better structural flexibility and adaptability, and can maintain stability by making minor adjustments to their structure when facing changes in the external environment, broadening their application range. At the same time, amorphous MOF materials also have greater advantages in processing and molding, effectively reducing the generation of intergranular defects and preparing more stable membrane materials.
[0004] Among numerous MOF materials, copper-based MOFs (Cu-MOFs) have attracted widespread attention due to their unique electronic structure and catalytic properties. Copper, as a relatively abundant and inexpensive metallic element, gives Cu-MOFs a significant cost advantage. Furthermore, Cu-MOFs have shown promising application potential in areas such as carbon dioxide conversion, organic pollutant degradation, and photodynamic therapy. However, current research on Cu-MOFs largely focuses on the crystalline form, while research on amorphous Cu-MOFs is still in its early stages.
[0005] Therefore, developing a simple, efficient, and low-cost method for preparing amorphous Cu-MOF materials, conducting in-depth research on their performance regulation mechanisms, and expanding their application scenarios are of significant scientific importance and practical application value. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing amorphous Cu-MOF and its application, providing a simple, efficient, and low-cost method for preparing amorphous Cu-MOF materials, which can be applied to the preparation of colorimetric sensors.
[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing amorphous Cu-MOF, wherein the preparation method includes the following steps:
[0008] S1. Preparation of crystalline Cu-MOF: Cu-MOF was synthesized by solvothermal method using CuCl2 as copper source and 4,4′-bipyridine as ligand;
[0009] S2. Preparation of amorphous Cu-MOF: The Cu-MOF obtained in S1 was etched with ammonia water to obtain amorphous Cu-MOF (aCu-MOF).
[0010] The present invention is further configured such that the specific operation for synthesizing crystalline Cu-MOF in S1 is as follows:
[0011] (1) Dissolve 0.204 g CuCl2 and 0.468 g 4,4'-bipyridine in 270 mL of ultrapure water and 30 mL of ethanol, respectively;
[0012] (2) Stir vigorously at room temperature while adding 4,4'-bipyridine solution dropwise to CuCl2 aqueous solution;
[0013] (3) After the addition is complete, continue stirring for 2 hours;
[0014] (4) After the reaction is complete, the product is washed with ethanol and ultrapure water in sequence, centrifuged, and the process is repeated three times.
[0015] (5) Collect the obtained blue precipitate and dry it under vacuum at 60 °C to obtain Cu-MOF for later use.
[0016] The present invention is further configured such that the specific operation for preparing amorphous Cu-MOF in step S2 is as follows:
[0017] (1) Weigh 0.03 g Cu-MOF and place it in a solution of 60 mL anhydrous ethanol and water of equal volume. Sonicate for 20 min to disperse it fully.
[0018] (2) Then add 800 μL of ammonia and continue etching for 7 h;
[0019] (3) After the reaction is complete, the product is washed repeatedly with ethanol and ultrapure water, centrifuged and collected, and then vacuum dried overnight at 60 °C. The resulting sample is aCu-MOF.
[0020] The present invention further provides an amorphous Cu-MOF prepared by the above preparation method.
[0021] The present invention further provides an application of the amorphous Cu-MOF, which can be used in the fabrication of colorimetric sensors.
[0022] The present invention is further configured such that the amorphous Cu-MOF serves as a signal conversion element of a colorimetric sensor, enabling the detection of ampicillin under neutral conditions.
[0023] The present invention is further configured such that the amorphous Cu-MOF uses thiram as an auxiliary factor to construct a thiram colorimetric sensing system with high selectivity.
[0024] In summary, the present invention has the following beneficial effects:
[0025] The synthesis of amorphous Cu-MOF in this invention is simple, easy to mass-produce industrially, and can bring certain economic benefits. It exhibits excellent POD-like catalytic performance and can be used as a signal conversion element in colorimetric sensors to achieve reliable detection of ampicillin under neutral conditions. Although it lacks intrinsic OXD activity, its catalytic function is significantly activated in the presence of thiram. Using thiram as a cofactor of aCu-MOF, a highly selective thiram colorimetric sensing system can be constructed. Attached Figure Description
[0026] Figure 1 From left to right: Left: TEM image of the original Cu-MOF; Middle: TEM image of the amorphous Cu-MOF; Right: XRD patterns of the original Cu-MOF and the amorphous Cu-MOF.
[0027] Analysis: TEM shows that the original Cu-MOF exhibits a typical micron-scale sheet-like morphology (left). After etching with ammonia, the resulting non-static Cu-MOF morphology transforms into rough-surfaced nanospheres with a significantly increased pore size (middle). XRD analysis shows that the original Cu-MOF has good crystallinity, while the diffraction peaks of the amorphous Cu-MOF have essentially disappeared (right).
[0028] Figure 2 From left to right: Left: Calibration curve of ampicillin colorimetric sensor based on amorphous Cu-MOF; Middle and right: Anti-interference performance of colorimetric sensor.
[0029] Analysis: A signal-attenuated colorimetric sensor for ampicillin detection was constructed using TMB as the colorimetric probe and amorphous Cu-MOF as the signal conversion element. Results showed that within the ampicillin concentration range of 0.04–14 μg / mL, the absorbance of the system exhibited a good linear relationship with the concentration, with a detection limit as low as 0.028 μg / mL (left). The constructed colorimetric sensor was resistant to interference from a range of metal ions, bioactive small molecules, and antibiotics (middle, right).
[0030] Figure 3 From left to right: Left: Calibration curve of the Fumei dual colorimetric sensor based on amorphous Cu-MOF; Middle and right: Anti-interference performance of the colorimetric sensor.
[0031] Analysis: A signal-enhanced colorimetric sensor for the detection of thiram was constructed using TMB as the colorimetric probe and amorphous Cu-MOF as the signal conversion element. Results showed that the absorbance of the system exhibited a good linear relationship with the concentration of thiram within the ranges of 0.06–2.5 μg / mL and 2.5–7.0 μg / mL. The constructed colorimetric sensor was resistant to interference from a range of ions, bioactive small molecules, and small organic molecule pollutants (middle and right). Detailed Implementation
[0032] The following is in conjunction with the appendix Figure 1-3 The present invention will be described in further detail below.
[0033] Example 1:
[0034] Cu-MOF was synthesized by solvothermal method using CuCl2 as copper source and 4,4′-bipyridine as ligand. Transmission electron microscopy (TEM) showed that the obtained material exhibited a typical micron-scale sheet-like morphology.
[0035] Example 2:
[0036] After etching the Cu-MOF synthesized in Example 1 with ammonia, the morphology of the sample transformed into rough-surfaced nanospheres with a significantly increased pore size, indicating a local rearrangement of its framework structure. X-ray diffraction (XRD) analysis showed that the original Cu-MOF had high crystallinity, while the diffraction peaks of the etched aCu-MOF basically disappeared, exhibiting amorphous characteristics.
[0037] Application Example 1: The materials synthesized in Examples 1 and 2 were tested for oxidase (POD) activity.
[0038] Under neutral conditions, Cu-MOF exhibits almost no peroxidase (POD)-like activity, while aCu-MOF demonstrates excellent POD-like catalytic performance. Based on this characteristic, aCu-MOF nanozymes can be used as signal conversion elements in colorimetric sensors to achieve reliable detection of ampicillin under neutral conditions.
[0039] Ampicillin was detected using aCu-MOF nanozyme as the signal conversion element of a colorimetric sensor: Different concentrations of ampicillin were added to a reaction system containing aCu-MOF (0.02 mg / mL), H₂O₂ (1.0 mM), and TMB (0.3 mM) in Tris-HCl buffer (20 mM, pH 7.0). After incubation at room temperature for 16 min, the absorbance of the reaction solution at 652 nm was measured (AL). 652 The system absorbance and ampicillin concentration were fitted to obtain a quantitative relationship, and the results are as follows: Figure 2 As shown.
[0040] On the other hand, Cu-MOF itself has almost no oxidase-like (OXD) activity, and the enhancing effect of thiram on its catalytic ability is very weak; although aCu-MOF itself lacks intrinsic OXD activity, its catalytic function is significantly activated in the presence of thiram. Using thiram as a cofactor of aCu-MOF nanozyme, a highly selective thiram colorimetric sensing system can be constructed.
[0041] A thiram-based colorimetric sensing system was constructed using thiram as a cofactor for aCu-MOF nanozyme: Different concentrations of thiram were added to a Tris-HCl buffer (20 mM, pH=4.0) containing aCu-MOF (0.015 mg / mL) and TMB (0.6 mM). After incubation at room temperature for 35 s, the absorbance at 652 nm was recorded (AL). 652 The quantitative relationship between the absorbance of the system and the concentration of thiram was fitted, and the results are as follows: Figure 3 As shown.
[0042] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.
Claims
1. A method for preparing amorphous Cu-MOF, characterized in that: The preparation method includes the following steps: S1. Preparation of crystalline Cu-MOF: Cu-MOF was synthesized by solvothermal method using CuCl2 as copper source and 4,4′-bipyridine as ligand; S2. Preparation of amorphous Cu-MOF: The Cu-MOF obtained in S1 was etched with ammonia water to obtain amorphous Cu-MOF.
2. The method for preparing amorphous Cu-MOF according to claim 1, characterized in that: The specific steps for synthesizing crystalline Cu-MOF in S1 are as follows: (1) Dissolve 0.204 g CuCl2 and 0.468 g 4,4'-bipyridine in 270 mL of ultrapure water and 30 mL of ethanol, respectively; (2) Stir vigorously at room temperature while adding 4,4'-bipyridine solution dropwise to CuCl2 aqueous solution; (3) After the addition is complete, continue stirring for 2 hours; (4) After the reaction is complete, the product is washed with ethanol and ultrapure water in sequence, centrifuged, and the process is repeated three times. (5) Collect the obtained blue precipitate and dry it under vacuum at 60 °C to obtain Cu-MOF for later use.
3. The method for preparing amorphous Cu-MOF according to claim 1, characterized in that: The specific steps for preparing amorphous Cu-MOF in S2 are as follows: (1) Weigh 0.03 g Cu-MOF and place it in a solution of 60 mL anhydrous ethanol and water of equal volume. Sonicate for 20 min to disperse it fully. (2) Then add 800 μL of ammonia and continue etching for 7 h; (3) After the reaction is complete, the product is washed repeatedly with ethanol and ultrapure water, centrifuged and collected, and then vacuum dried overnight at 60 °C. The resulting sample is aCu-MOF.
4. The amorphous Cu-MOF prepared by the preparation method according to any one of claims 1-3.
5. The application of the amorphous Cu-MOF according to claim 4, characterized in that: Application of the amorphous Cu-MOF in the preparation of colorimetric sensors.
6. The application of the amorphous Cu-MOF according to claim 5, characterized in that: The amorphous Cu-MOF, used as a signal conversion element in a colorimetric sensor, can detect ampicillin under neutral conditions.
7. The application of the amorphous Cu-MOF according to claim 5, characterized in that: The amorphous Cu-MOF, with thiram as an auxiliary factor, can be used to construct a thiram colorimetric sensing system with high selectivity.