Fluorescent Probe Based on Zinc Metal-Organic Framework Material with Dual Organic Ligands, Preparation Method and Application Thereof

Abstract

The present invention proposes a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material, its preparation method and application, and belongs to the field of novel functional nanomaterial detection technology. The preparation method comprises: mixing an acetonitrile solution of a Zn(II) salt, an acetonitrile solution of 2-methylimidazole, and an acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridine-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl, ultrasonically treating, reacting, collecting the precipitate, and vacuum drying to obtain a fluorescent probe. The obtained probe is mainly used for the detection of soluble Aβ in serum, with a detection limit as low as 3.22nM. The fluorescence response between Aβ and Zn-MOFs is rapid and can be completed within 10 minutes. This design has potential application value in the low-cost, rapid, and accurate detection of trace target substances in serum or other complex body fluids.

Description

Technical Field

[0001] The present invention belongs to the technical field of novel functional nanomaterial detection, and particularly relates to a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material, and a preparation method and application thereof. Background Art

[0002] Alzheimer's disease (AD) is a neurodegenerative disorder with an insidious onset. To date, there is no cure for AD. Research suggests this may be due to limited clinical diagnostic methods. Once diagnosed, irreversible brain damage has already occurred, making it difficult for medications to be effective. Therefore, early diagnosis is crucial for the prevention and treatment of AD.

[0003] Studies have found that hydrophobic β-amyloid peptide (Aβ) in serum shows abnormalities 10-15 years before AD patients develop obvious symptoms, making it an effective biomarker for early diagnosis of AD. Currently, immunoassays based on antigen-antibody reactions combined with analytical instruments such as mass spectrometry, surface plasmon resonance, and surface-enhanced Raman spectroscopy are the most commonly used methods for quantifying serum Aβ. However, the poor stability of antibodies, expensive equipment, and complex and time-consuming professional operations have limited the widespread application of this method.

[0004] In comparison, small molecule fluorescent probes have advantages in that they are cheap, have stable physicochemical properties, are easy to store, and the signals are easy to detect. However, due to the complex composition of serum and the low abundance of Aβ, most small molecule fluorescent probes have limited targeting and can usually only work in buffer or diluted serum samples. For example, existing studies (A Simple Approach to Quantitative Determination of Soluble Amyloid-β Peptides Using a Ratiometric Fluorescence Probe. Biosens. Bioelectron., 2019, 142, 111518) disclosed the reaction of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl (BPNS) with Zn 2+ The combination was used as a fluorescent probe to detect soluble Aβ species. However, the probes obtained by this method had poor sensitivity and a relatively high detection limit. Summary of the Invention

[0005] The present invention proposes a fluorescent probe based on a dual-organic ligand zinc-based metal-organic framework material, as well as its preparation method and application. The obtained fluorescent probe has strong anti-interference ability and can be used for the quantitative detection of soluble Aβ in undiluted serum with a low detection limit. The detection method is simple to operate, low-cost, stable and reliable, and is of great significance for the early diagnosis of AD.

[0006] The present invention provides a method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material, comprising the following steps:

[0007] An acetonitrile solution of Zn(II) salt, an acetonitrile solution of 2-methylimidazole, and an acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl are mixed, ultrasonically treated, reacted, and the precipitate is collected and vacuum dried to obtain a fluorescent probe.

[0008] Furthermore, the concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 3-7 mM.

[0009] Furthermore, the concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 5 mM.

[0010] Furthermore, the reaction time is 12-30 hours; preferably, the reaction time is 24 hours.

[0011] Furthermore, the molar concentration ratio of the acetonitrile solution of Zn(II) salt, the acetonitrile solution of 2-methylimidazole, and the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is (1-2):(1-2):(0.5-1.5).

[0012] Furthermore, the ultrasonic treatment time is 15-30 min; preferably, the ultrasonic treatment time is 25 min.

[0013] Furthermore, the vacuum drying time is 5-10 h; preferably, the vacuum drying time is 6 h.

[0014] Furthermore, the Zn(II) salt is zinc nitrate hexahydrate, zinc sulfate heptahydrate or zinc chloride; preferably, the Zn(II) salt is zinc nitrate hexahydrate.

[0015] The present invention also provides a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material prepared by any of the above-mentioned preparation methods.

[0016] The present invention also proposes the use of the fluorescent probe based on the dual organic ligand zinc-based metal organic framework material in detecting soluble Aβ in serum.

[0017] The present invention has the following advantages:

[0018] The present invention uses the fluorescent small molecule BPNS and dimethylimidazole as dual organic ligands and utilizes self-assembly technology to prepare zinc-based fluorescent probes Zn-MOFs. 2-Methylimidazole and zinc ions can form a variety of metal-organic framework forms. After adding N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl (BPNS), 2-pyridylbenzothiazole can coordinate with zinc ions and participate in the formation of Zn-MOFs in a self-assembly manner. The resulting Zn-MOFs metal-organic framework structure has a complete and moderate flower shape and hydrophobic pores. It can target and enrich serum Aβ through hydrophobic interaction and size exclusion effect, thereby improving the anti-interference ability of the probe.

[0019] The obtained probe can be directly used for the detection limit of soluble Aβ in undiluted serum as low as 3.22 nM, which is two orders of magnitude lower than that of BPNS in 80-fold diluted serum. The fluorescence response between Aβ and Zn-MOFs is rapid and can be completed within 10 minutes. This design has potential application value in the low-cost, rapid and accurate detection of trace target substances in serum or other complex body fluids. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 This is a scanning electron microscope (SEM) image of the fluorescent probe obtained in Example 1 of the present invention;

[0022] Figure 2 The transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) test results of the fluorescent probe obtained in Example 1 of the present invention are shown;

[0023] Figure 3 The following are Fourier transform infrared (FTIR) spectra of the fluorescent probes obtained in Example 1 and Comparative Example 2 of the present invention;

[0024] Figure 4 The XRD (A) and XPS (B) patterns of the fluorescent probes obtained in Example 1 and Comparative Example 2 of the present invention are shown;

[0025] Figure 5 Scanning electron microscope (SEM) images of the fluorescent probes obtained in Examples 4 to 6 of the present invention;

[0026] Figure 6 This is a scanning electron microscope (SEM) image of the fluorescent probe obtained in Comparative Example 1 of the present invention;

[0027] Figure 7 This is the linear relationship curve between Aβ monomer and fluorescence intensity in Example 1 of the present invention;

[0028] Figure 8 This is the water vapor adsorption isotherm of the fluorescent probe obtained in Example 1 of the present invention;

[0029] Figure 9 N2 adsorption-desorption isotherm of the fluorescent probe obtained in Example 1 of the present invention (A) and the pore distribution of Zn-MOFs calculated by DFT method (B). DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0031] One embodiment of the present invention provides a method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal-organic framework material, comprising the following steps:

[0032] An acetonitrile solution of Zn(Ⅱ) salt, an acetonitrile solution of 2-methylimidazole, and an acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl (BPNS) were mixed, ultrasonically treated, reacted, and the precipitate was collected and vacuum dried to obtain a fluorescent probe (Zn-MOFs).

[0033] In this embodiment of the present invention, the fluorescent small molecule BPNS and dimethylimidazole are used as dual organic ligands, and self-assembly technology is used to prepare zinc-based fluorescent probes Zn-MOFs. This fully utilizes the targeted enrichment characteristics of MOFs and improves the anti-interference ability of the probe. 2-Methylimidazole and zinc ions can form a variety of metal-organic framework morphologies. After adding N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl (BPNS), 2-pyridylbenzothiazole can coordinate with zinc ions and participate in the formation of Zn-MOFs in a self-assembly manner. The resulting Zn-MOFs metal-organic framework structure has a more complete flower pattern and a moderate size, forming hydrophobic pores. It can target and enrich serum Aβ through hydrophobic interactions and size exclusion effects, greatly improving the anti-interference ability of the probe and protecting the probe from interfering substances in the serum. Moreover, BPNS participates in the formation of Zn-MOFs probes as a self-fluorescent organic ligand, which is not only easy to prepare but also can effectively avoid tedious chemical modification or leakage of fluorescent small molecules caused by embedding or covalent binding, greatly improving the stability and accuracy of the probe.

[0034] In one embodiment of the present invention, the reaction time is 12-30 hours; preferably, the reaction time is 24 hours.

[0035] In one embodiment of the present invention, the reaction is carried out at room temperature; more specifically, the reaction temperature is 15-30°C.

[0036] In one embodiment of the present invention, the concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 3 to 7 mM; preferably, the concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 5 mM.

[0037] In one embodiment of the present invention, the molar concentration ratio of the acetonitrile solution of Zn(II) salt, the acetonitrile solution of 2-methylimidazole, and the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 1-2:(1-2):(0.5-1.5).

[0038] In the present embodiment, acetonitrile was selected as the solvent because BPNS has good solubility in acetonitrile. If other solvents, such as methanol, were used, BPNS would have poor solubility and would not easily form a complete flower-like structure.

[0039] In one embodiment of the present invention, the ultrasonic treatment time is 15-30 min; preferably, the ultrasonic treatment time is 25 min.

[0040] In one embodiment of the present invention, the vacuum drying time is 5-10 h; preferably, the vacuum drying time is 6 h.

[0041] In one embodiment of the present invention, the Zn(II) salt is zinc nitrate hexahydrate, zinc sulfate heptahydrate, or zinc chloride. Preferably, the Zn(II) salt is zinc nitrate hexahydrate. The Zn(II) salt is a divalent zinc salt.

[0042] In one embodiment of the present invention, the precipitate is collected by centrifugation.

[0043] One embodiment of the present invention also proposes a fluorescent probe based on a dual organic ligand zinc-based metal-organic framework material prepared using the above-mentioned preparation method. Compared with ordinary fluorescent probes, in the present invention, 2-methylimidazole and zinc ions can form a variety of metal-organic framework forms. After adding N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl (BPNS), 2-pyridylbenzothiazole can also coordinate with zinc ions and participate in the formation of Zn-MOFs in a self-assembly manner. The resulting Zn-MOFs metal-organic framework structure has a more complete flower pattern and a moderate size, forming a hydrophobic cavity, which can target and enrich serum Aβ through hydrophobic interaction and size exclusion effect, greatly improving the anti-interference ability of the probe and protecting the probe from interfering substances in the serum. The complete flower-shaped structure and hydrophobic cavity of the obtained fluorescent probe lay the foundation for the subsequent detection of soluble Aβ in serum, making the detection limit of the fluorescent probe lower and the detection speed faster.

[0044] One embodiment of the present invention also proposes the application of the above-mentioned fluorescent probe based on dual organic ligand zinc-based metal-organic framework materials in the detection of soluble Aβ in serum. The probe obtained in the embodiment of the present invention has good anti-interference performance and can be directly applied to the detection of undiluted serum samples. The detection limit of soluble Aβ in undiluted serum is as low as 3.22 nM, which is two orders of magnitude lower than that of BPNS in 80-fold diluted serum, effectively improving the accuracy of detection. In addition, the fluorescence response between Aβ and Zn-MOFs is rapid, and the entire detection process can be completed within 10 minutes. This design has potential application value in the low-cost, rapid and accurate detection of trace target substances in serum or other complex body fluids, and provides method and principle support for the design of a new type of efficient fluorescent probe for targeted detection of Aβ.

[0045] Specifically, the application includes the following steps:

[0046] The fluorescent probe was co-incubated with blank serum added with different concentration gradients of Aβ. The changes in the fluorescence intensity of the system were recorded using a microplate reader. Based on the linear relationship between fluorescence intensity and soluble Aβ concentration, a standard curve was established, and the minimum detection limit was calculated based on the standard curve.

[0047] Specifically, the formula for calculating the limit of detection is: LOD=3σ / S; where: σ is the standard deviation of the blank serum, and S is the slope of the linear curve.

[0048] In one embodiment of the present invention, the co-incubation time is 10-15 min, preferably 10 min.

[0049] In one embodiment of the present invention, the co-incubation temperature is 30-40°C, preferably 37°C.

[0050] In one embodiment of the present invention, the excitation wavelength is fixed at 332 nm, and the fluorescence intensity value at 526 nm is collected.

[0051] In one embodiment of the present invention, the concentration gradient of the Aβ solution can be 10, 20, 30, 40, 50, and 60 nM. According to specific needs, the embodiment of the present invention can calculate the concentration of the serum sample to be tested by testing the fluorescence intensity of the serum sample to be tested and substituting the result into the standard curve.

[0052] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0053] Example 1 A method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material comprises the following steps:

[0054] Zinc nitrate hexahydrate (Zn(NO3)·6H2O) and 2-methylimidazole (2-MIM) were dissolved in acetonitrile to obtain Zn(NO3)·6H2O solution and 2-MIM solution with a final concentration of 20 mM respectively; 5 mM BPNS acetonitrile solution was mixed with Zn(NO3)·6H2O solution, 2-MIM solution was added, and after mixing, ultrasonic treatment was performed for 25 minutes. The mixture was then allowed to stand at room temperature for 24 hours. Finally, the precipitate was centrifuged and washed three times with acetonitrile. The precipitate was vacuum dried at room temperature for 6 hours to obtain the fluorescent probe Zn-MOFs. The structure of the fluorescent probe was characterized using conventional SEM, FTIR, EDS, XRD and XPS determination methods. The results are shown in Figure 2. Figures 1 to 4 .

[0055] Figure 1 It shows that the fluorescent probe Zn-MOFs presents a flower-like structure with compact petals, complete morphology and uniform dispersion, while the Zn-MOFs prepared by traditional methods have a single microscopic morphology.

[0056] Figure 2 TEM and EDS energy spectrum element detection results, Figure 2 Transmission electron microscopy revealed that Zn-MOFs exhibited flower-like structures with particle sizes of approximately 10-12 μm, consistent with the SEM results. Elemental composition revealed that C, N, O, and S reflect the elements present on the surface of the fluorescent probe. S and O were detected in Zn-MOFs and were evenly distributed throughout the petals, primarily derived from BPNS. C and N were also evenly distributed throughout the flower-like structures, originating from BPNS and 2-methylimidazole. The overlay graph shows a superposition of all elements. This result also confirms that BPNS participates in the formation of the Zn-MOF flower-like structure.

[0057] Figure 3 is the FTIR graph, Figure 3The horizontal axis is the transmittance. 2+ The FTIR results of the complex and BPNS were compared. Figure 3 The results show that BPNS and Zn-MOFs have a high affinity to 1590 cm -1 There is an obvious absorption peak at 1463-1473 cm -1 and 600-1000 cm -1 The absorption in the range corresponds to the stretching vibration of thiazole and naphthalene rings, which shows that BPNS and Zn-MOFs are successfully combined. 2+ It can be seen that both are at 421 cm -1 There is a specific absorption peak at the position of Zn, which is attributed to the stretching vibration of zinc and nitrogen. 2+ The coordination method participates in the formation of Zn-MOFs.

[0058] Figure 4 XRD (A) and XPS (B) patterns. Figure 4 The horizontal axis of (A) is the scanning angle of the diffractometer, and the vertical axis is the diffraction intensity; Figure 4 The horizontal axis of (B) is the binding energy, and the vertical axis is the diffraction intensity. 2+ The XRD results of the complex and BPNS were compared to determine the 2+ The XPS results of the complexes were compared. The XRD results showed that the peak intensity of Zn-MOFs decreased and there were many overlapping peaks with BPNS, indicating that the binding mechanism of Zn-MOFs was mainly BPNS and Zn 2+ The XPS results show that BPNS is a kind of 2+ The coordination method participates in the formation of Zn-MOFs.

[0059] Example 2 A method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material comprises the following steps:

[0060] Zinc nitrate hexahydrate (Zn(NO3)·6H2O) and 2-methylimidazole (2-MIM) were dissolved in acetonitrile to a final concentration of 20 mM for Zn(NO3)·6H2O and 10 mM for 2-MIM. A 5 mM BPNS acetonitrile solution was mixed with a Zn(NO3)·6H2O solution, and the 2-MIM solution was added. After mixing, the mixture was sonicated for 25 minutes. The mixture was then allowed to stand at room temperature for 24 hours. The precipitate was centrifuged, washed three times with acetonitrile, and dried under vacuum at room temperature for 6 hours to obtain the fluorescent probe Zn-MOFs.

[0061] Example 3 A method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material comprises the following steps:

[0062] Zinc nitrate hexahydrate (Zn(NO3)·6H2O) and 2-methylimidazole (2-MIM) were dissolved in acetonitrile to a final concentration of 20 mM. 5 mM BPNS acetonitrile solution was mixed with Zn(NO3)·6H2O solution, and 2-MIM solution was added. After mixing, the mixture was ultrasonically treated for 15 min, and then allowed to stand at room temperature for 24 h. Finally, the precipitate was centrifuged, washed three times with acetonitrile, and dried under vacuum at room temperature for 8 h to obtain Zn-MOFs.

[0063] Examples 4-6

[0064] Same as Example 1, except that the final concentration of BPNS acetonitrile solution was changed to 3, 4 and 7 mM during the preparation of fluorescent probe, while other conditions remained unchanged. Figure 5 (A) Figure 5 (B) Figure 5 (C) The results show that as the concentration of BPNS increases, Zn-MOFs take on a flower-like shape with denser petals. Figure 1 and Figure 5 By comparison, when the BPNS concentration is 5 mM, the Zn-MOFs petals are sparse, the structure is complete, and the dispersion is better.

[0065] Comparative Example 1

[0066] Same as Example 1, except that the fluorescent probe synthesis solvent was replaced by methanol solution instead of acetonitrile solution. Figure 6 The figure shows that regular crystals cannot be formed in methanol solution.

[0067] Comparative Example 2

[0068] BPNS-Zn was obtained by incubating 10 mM Zn(NO3)2·6H2O and 5 mM BPNS in acetonitrile at 25°C for 30 min. 2+ complex.

[0069] Test Example 1 Application of fluorescent probe based on dual organic ligand zinc-based metal-organic framework materials in the detection of soluble Aβ in serum

[0070] The Zn-MOFs solid obtained in Example 1 was dissolved in Tris-HCl buffer to obtain a Zn-MOFs buffer for later use, wherein the Tris-HCl buffer was used; 10, 20, 30, 40, 50, and 60 nM Aβ solutions were prepared in blank serum, respectively, and incubated with Zn-MOFs serum (the concentration of Zn-MOFs in serum was 2 mg / mL) at 37°C for 10 min. The fluorescence intensity of the supernatant at 526 nm (λex = 332 nm) was measured using a microplate reader. A standard curve was established based on the linear relationship between fluorescence intensity and soluble Aβ concentration, and fitted using OriginPro 8.5 software. The results are shown in Figure 2. Figure 7 ,in Figure 7 The horizontal axis is the Aβ concentration, and the vertical axis is the fluorescence intensity. The detection limit is calculated according to the formula: LOD = 3σ / S; where σ is the standard deviation of the blank serum and S is the slope of the linear curve. Figure 7 It can be seen that the linear relationship is good, and the detection limit is 3.22 nM according to the formula.

[0071] The BCA assay was used to validate the Zn-MOFs standard curve for Aβ detection, and the results are shown in Table 1. Zn-MOFs detected soluble Aβ in undiluted serum with good recovery and a relative standard deviation of less than 5%. Therefore, this probe can be used for the quantitative detection of soluble Aβ in undiluted serum.

[0072] Table 1

[0073]

[0074] In order to further explore the characteristics of the fluorescent probe itself and its low detection limit performance, the water vapor adsorption isotherm, N2 adsorption-desorption isotherm and mesopore distribution of the fluorescent probe were tested respectively.

[0075] Specifically, the dynamic water vapor analyzer (DVS Adventure) was used to analyze the hydrophilicity and hydrophobicity of Zn-MOFs molecules. First, the sample was placed in a clean crucible, the corresponding parameters were set, and the change in mass with the increase in water vapor pressure was measured at the same time interval to obtain the adsorption isotherm. The results are shown in Figure 8 ,in, Figure 8 The horizontal axis is relative pressure, and the vertical axis is water absorption.

[0076] Figure 8Water vapor adsorption isotherms using the fluorescent probe show that the water uptake rate of Zn-MOFs remains essentially unchanged with increasing P / P0, indicating that Zn-MOFs are highly hydrophobic. Generally speaking, Aβ is hydrophobic compared to most intrinsically hydrophilic interfering substances in serum. This strong hydrophobicity enables Zn-MOFs to selectively interact with hydrophobic Aβ, while minimizing interaction with interfering substances. In summary, Zn-MOFs can selectively enrich Aβ, significantly reducing the detection limit.

[0077] The porosity analysis was performed using an ASAP2460. The instrument measured the N2 adsorption / desorption isotherm of the sample at 77.3 K. A certain amount of sample was weighed and placed in a dedicated sample tube for testing. The sample was pretreated to remove impurities, and the mesopore size distribution was calculated using the density functional theory (DFT) model. The results are shown in Figure 9 , Figure 9 The horizontal axis of (A) is the relative pressure, and the vertical axis is the amount of N2 adsorption; Figure 9 The abscissa of (B) is the pore width, and the ordinate is the pore area.

[0078] Figure 9 The N2 adsorption-desorption isotherm of the fluorescent probe (A) and the Zn-MOF mesopore distribution calculated by density functional theory (DFT) (B) show that Zn-MOFs exhibit type IV isotherms with distinct hysteresis loops, indicating the presence of mesopores. Density functional theory (DFT) was used to calculate the mesopore size distribution of Zn-MOFs. The results show that the pore sizes on the Zn-MOF petals are primarily distributed between 10 and 13 nm, allowing Aβ, rather than HSA, TRF, or BSA, to enter the interior. By blocking interfering substances, the size exclusion effect also contributes to the selective enrichment of Aβ, improving detection accuracy.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a fluorescent probe based on a dual organic ligand zinc-based metal organic framework material, characterized in that: The steps include: An acetonitrile solution of Zn(II) salt, an acetonitrile solution of 2-methylimidazole, and an acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl are mixed, ultrasonically treated, reacted, and the precipitate is collected and vacuum dried to obtain a fluorescent probe; The concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 3-7 mM; The molar concentration ratio of the acetonitrile solution of Zn(Ⅱ) salt, the acetonitrile solution of 2-methylimidazole, and the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is (1-2):(1-2):(0.5-1.5).

2. The preparation method according to claim 1, characterized in that The concentration of the acetonitrile solution of N-(6-(benzothiazol-2-yl)pyridin-3-yl)-5-(dimethylamino)naphthalene-1-sulfonyl is 5 mM.

3. The preparation method according to claim 1, characterized in that The reaction time is 12-30h.

4. The preparation method according to claim 3, characterized in that The reaction time is 24 hours.

5. The preparation method according to claim 1, characterized in that The ultrasonic treatment time is 15-30 min.

6. The preparation method according to claim 5, characterized in that The ultrasonic treatment time was 25 min.

7. The preparation method according to claim 1, characterized in that The vacuum drying time is 5-10 h.

8. The preparation method according to claim 1, characterized in that The vacuum drying time was 6 h.

9. The preparation method according to claim 1, characterized in that The Zn(II) salt is zinc nitrate hexahydrate, zinc sulfate heptahydrate or zinc chloride.

10. The preparation method according to claim 9, characterized in that The Zn(II) salt is zinc nitrate hexahydrate.

11. A fluorescent probe based on a dual organic ligand zinc-based metal organic framework material prepared by the preparation method according to any one of claims 1 to 10.

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