Preparation method and application of indium-based MOF (JOU-36) fluorescent nano material

Abstract

The invention belongs to the technical field of fluorescence detection, and particularly relates to an indium-based MOF (Metal Organic Framework) fluorescent nano material as well as a preparation method and application thereof, network interpenetration of MOF is regulated and controlled by finely controlling synthesis conditions so as to adjust the size of a pore channel, and high-sensitivity detection of a nitro-aromatic compound is realized. The preparation method comprises the following steps: uniformly mixing In (NO3) 3.4. 5H2O, H4SFT, DMF and HNO3 in an ultrasonic manner, transferring the mixture into a 4mL pressure-resistant glass bottle, and reacting in a drying oven at 120 DEG C for 24 hours; and cooling to room temperature, carrying out ultrasonic treatment, centrifuging, washing, and drying in air to obtain a yellow crystal, namely In-MOF (JOU-36). After an equal amount of nitro aromatic compound is added into the DMF dispersion liquid of In-MOF (JOU-36), the fluorescence is completely quenched within several seconds, and the quenching constant for identifying the nitro aromatic compound reaches 914.7 M <-1 >. The device has the advantages of high detection speed, high efficiency and convenience in recycling.

Description

Technical Field

[0001] The present invention relates to the field of fluorescence detection, and specifically to a method for preparing an In-MOF (JOU-36) nanomaterial with fluorescence detection performance, and its application in highly sensitive detection of nitroaromatic compounds. Background Art

[0002] Nitroaromatic compounds (NACSs) are important raw materials for the production of pesticides, dyes, pharmaceuticals, and explosives. However, their acute toxicity, mutagenicity, and high chemical stability allow them to remain in the natural environment for long periods of time, posing a serious threat to humans and ecosystems. Therefore, it is very important to detect the concentration of NACSs in the environment. Currently, techniques such as gas chromatography (GC) and cyclic voltammetry ion mobility spectrometry (IMS) have been used to detect NACs. However, these techniques are severely limited by complex pretreatment, long detection cycles, portability, and high operating costs. Therefore, the development of efficient and sensitive NACs detection technologies is of great significance. In recent years, sensing platforms based on fluorescence technology have attracted particular attention due to their advantages such as rapid response, high sensitivity, and simple operation. The design and synthesis of new fluorescent probe materials has become an important research direction in this field.

[0003] Metal-organic frameworks (MOFs) are a new type of porous material formed by metal ions (clusters) connecting organic ligands. Due to their highly tunable structure and excellent stability, they are widely used in catalysis, fluorescence, adsorption and separation. Interpenetration is a common phenomenon in MOFs, mainly when the pores and topological structure allow, there are two or more entangled and interlocked sublattices in the same crystal. By regulating the interpenetration of MOF networks under temperature and other conditions, the pore size and structural framework stability of MOFs can be adjusted. In terms of fluorescence sensing, MOFs have the advantages of fast response, high sensitivity and simple operation due to their excellent fluorescence properties, unique pore structure and designable functional recognition sites. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation and application of In-MOF (JOU-36) nanomaterials with fluorescence detection performance, and to provide a simple and efficient method for detecting nitroaromatic compounds, which overcomes the problems of the above-mentioned prior art such as complex pretreatment, long detection cycle, portability and high operating cost.

[0005] Another object of the present invention is to provide an indium-based metal organic framework nanomaterial, namely [(CH3)2NH2][In(SFT)]·3.5(DMF)·3.5(H2O) (JOU-36).

[0006] Another object of the present invention is to provide a method for preparing the aforementioned indium-based metal-organic framework nanomaterial. The preparation method of the present invention can simply and efficiently produce the aforementioned indium-based metal-organic framework nanomaterial, and the prepared material has properties such as rapid response and high sensitivity.

[0007] The present invention also provides a method for preparing the indium-based metal organic framework nanomaterial as described above, comprising the following steps:

[0008] S1: placing an indium salt in a solvent and stirring it for the first time, then adding H4SFT and stirring it for the second time, adding nitric acid and stirring it for the third time to obtain a mixed solution;

[0009] S2: placing the mixed solution in a pressure-resistant glass bottle for solvothermal reaction, and obtaining an In-MOF nanomaterial with fluorescence detection performance after treatment.

[0010] Furthermore, based on the above technical solution, the indium salt is In(NO3)3·4.5H2O.

[0011] Furthermore, based on the above technical solution, the solvent is N,N-dimethylformamide.

[0012] Furthermore, based on the above technical solution, the nitric acid is HNO3 (65wt%).

[0013] Furthermore, based on the above technical solution, the mass ratio of the indium salt to the solvent is (0.0005-0.0015):1, preferably 0.001:1;

[0014] And / or, the mass ratio of the indium salt to the H4SFT is (0.4-1.2):1, preferably 0.8:1.

[0015] Furthermore, based on the above technical solution, in step S1, the first stirring is ultrasonic stirring;

[0016] Preferably, the ultrasonic stirring time is 15-25 min, preferably 20 min;

[0017] And / or, the second stirring comprises:

[0018] The temperature is 20-30°C, the stirring speed is 130-150r / min, and the stirring time is 25-35min, preferably 30min;

[0019] And / or, the third stirring comprises:

[0020] The temperature is 20-30°C, the stirring speed is 130-150r / min, and the stirring time is 25-35min, preferably 30min;

[0021] Furthermore, based on the above technical solution, the solvent thermal reaction includes:

[0022] The temperature is 100-140°C, preferably 120°C, and the reaction time is 20-30h, preferably 24h.

[0023] Furthermore, based on the above technical solution, the treatment includes ultrasonic stirring, centrifugation, washing and drying;

[0024] Preferably, the ultrasonic stirring time is 10-12 min;

[0025] Preferably, the centrifugal speed is 8000-9000 r / min and the time is 5-6 min;

[0026] Preferably, the washing detergent is DMF;

[0027] Preferably, the drying conditions include:

[0028] The drying temperature is 20-40°C and the drying time is 12-16 hours.

[0029] The present invention also provides an application of the In-MOF (JOU-36) nanomaterial with fluorescence detection performance as described above or the In-MOF (JOU-36) nanomaterial prepared by the preparation method of the In-MOF (JOU-36) nanomaterial with fluorescence detection performance as described above.

[0030] Furthermore, based on the above technical solution, the In-MOF nanomaterial with fluorescence detection performance can be used to detect nitroaromatic compounds.

[0031] The beneficial technical effects of the present invention are as follows:

[0032] The In-MOF (JOU-36) fluorescent probe material synthesized using 4,4',4",4"'-(9,9'-spirobi[fluorene]-2,2',7,7'-tetrayl)tetrabenzoic acid as a ligand exhibits high fluorescence intensity and stability. The In-MOF fluorescent probe is capable of selectively identifying nitroaromatic compounds. Compared with existing detection methods, it exhibits greater sensitivity, stability, anti-interference properties, and recyclability. Furthermore, the preparation method is simple, recyclable, low-cost, minimally polluting, and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a three-dimensional simulated structure diagram of the In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention;

[0034] Figure 2The X-ray powder diffraction pattern of the In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention;

[0035] Figure 3 This is an infrared image of the In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention;

[0036] Figure 4 This is the fluorescence emission spectrum of the In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention;

[0037] Figure 5 This is a diagram showing the effect of In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention on detecting nitrobenzene;

[0038] Figure 6 This is a diagram showing the effect of In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention on detecting nitroaromatic compounds. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described below through specific embodiments.

[0040] Example 1

[0041] A method for preparing an indium-based MOF (JOU-36) fluorescent nanomaterial comprises the following steps:

[0042] Step 1: In(NO3)3·4.5H2O (0.026 mmol, 8.0 mg), H4SFT (0.013 mmol, 10.0 mg), DMF (1.1 mL) and HNO3 (90 μL, 65 wt%) were mixed by ultrasonication at room temperature for 5 min.

[0043] Step 2: The suspension was transferred to a 4 mL pressure-resistant glass bottle, and then reacted in an oven at 120° C. for 24 hours, followed by programmed cooling (2.5° C. / h) to room temperature.

[0044] Step 3: After the pressure-resistant glass bottle is cooled to room temperature, ultrasonic stirring is performed for 2 minutes, and then centrifugation is performed at a centrifugal speed of 9000 r / min for 3 minutes. The supernatant is discarded, and the lower layer of yellow powder is washed three times with 5 mL of DMF and dried at 20°C for 12 hours to obtain In-MOF (JOU-36) fluorescent nanomaterials.

[0045] Example 2

[0046] A method for preparing an indium-based MOF (JOU-36) fluorescent nanomaterial comprises the following steps:

[0047] Step 1: In(NO3)3·4.5H2O (0.013 mmol, 4.0 mg), H4SFT (0.02 mmol, 10.0 mg), DMF (1.1 mL) and HNO3 (90 μL, 65 wt%) were mixed by ultrasonication at room temperature for 5 min.

[0048] Step 2: The suspension was transferred to a 4 mL pressure-resistant glass bottle, and then reacted in an oven at 120° C. for 24 hours, followed by programmed cooling (2.5° C. / h) to room temperature.

[0049] Step 3: After the pressure-resistant glass bottle is cooled to room temperature, ultrasonic stirring is performed for 10 minutes, and then centrifugation is performed at a centrifugal speed of 9000 r / min for 3 minutes. The supernatant is discarded, and the lower layer of yellow powder is washed three times with 5 mL of DMF and dried at 20°C for 12 hours to obtain In-MOF (JOU-36) fluorescent nanomaterials.

[0050] Example 3:

[0051] An In-MOF nanomaterial with fluorescence detection performance comprises the following steps:

[0052] Step 1: In(NO3)3·4.5H2O (0.026 mmol, 8.0 mg), H4SFT (0.013 mmol, 10.0 mg), DMF (1.1 mL) and HNO3 (90 μL, 65 wt%) were mixed by ultrasonication at room temperature for 5 min.

[0053] Step 2: The suspension was transferred to a 4 mL pressure-resistant glass bottle, and then reacted in an oven at 130° C. for 24 hours, followed by programmed cooling (2.5° C. / h) to room temperature.

[0054] Step 3: After the pressure-resistant glass bottle is cooled to room temperature, ultrasonic stirring is performed for 10 minutes, and then centrifugation is performed at a centrifugal rate of 8000 r / min for 3 minutes. The supernatant is poured out, and the lower layer of yellow powder is washed three times with 5 mL DMF and dried at 20°C for 12 hours to obtain In-MOF (JOU-36) fluorescent nanomaterials.

[0055] Performance test experiment The In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention was subjected to X-ray single crystal diffraction analysis. The analysis showed that In-MOF (JOU-36) JOU-36 has a double interpenetrating three-dimensional network based on PtS topology, which crystallizes in the orthorhombic space group Ccca, and the unit cell parameters are as follows: In3+ in JOU-36 is coordinated with eight oxygen atoms from different carboxyl groups to form a capped triangular prism [In(COO)4] - The building blocks are connected by SFT4-ligands to form a three-dimensional anionic framework and are connected by [(CH3)2NH2] + Balance the frame charge. ( Figure 1 )

[0056] 2. The In-MOF (JOU-36) fluorescent probe material prepared in Example 1 of the present invention was subjected to X-ray powder diffraction analysis. Figure 2 It can be seen that In-MOF exhibits good phase purity, which is basically consistent with the simulation peak.

[0057] 3. The In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention was subjected to infrared spectroscopy analysis. Figure 3 It can be seen that: at 4000-500cm -1 The H4SFT ligand and [In(COO)4] - The FTIR spectrum of the metal was characterized, and the corresponding characteristic absorption peaks were shown, which confirmed the coordination between the metal and the ligand.

[0058] 4. The fluorescence emission spectrum of the In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention was tested. Figure 4 As shown, the maximum emission wavelength of the In-MOF fluorescent nanomaterial prepared in Example 1 is 423 nm.

[0059] 5. The In-MOF (JOU-36) fluorescent nanomaterial prepared in Example 1 of the present invention was subjected to a nitrobenzene recognition experiment. The newly prepared In-MOF crystals were fully ground and dispersed in DMF (0.15 mg / mL). After ultrasonic treatment for 2 hours, the mixture was allowed to stand for 24 hours, and the supernatant was taken for later use. Detection of nitrobenzene: 20 μL of nitrobenzene (NB) solution was added dropwise to 2 mL of MOF dispersion, and the fluorescence intensity of the MOF dispersion after each addition of nitrobenzene was tested. At an excitation wavelength of 340 nm, the luminescence intensity was monitored in the range of 360 to 600 nm. Figure 5 It shows that with the gradual increase of the amount of nitrobenzene added, the fluorescence intensity of the MOF DMF dispersion gradually decreases, and the final quenching efficiency reaches 98%.

[0060] 6. The In-MOF fluorescent nanomaterial prepared in Example 1 of the present invention was subjected to an identification experiment for other nitroaromatic compounds. The newly prepared In-MOF crystals were fully ground and dispersed in DMF (0.15 mg / mL). After ultrasonic treatment for 2 hours, they were allowed to stand for 24 hours, and the supernatant was taken for later use. Detection of nitroaromatic compounds: 20 μL of nitroaromatic compound solution was added dropwise to 2 mL of MOF dispersion, and the fluorescence intensity of the MOF dispersion after each addition of nitrobenzene was measured. Under an excitation wavelength of 340 nm, the luminescence intensity was monitored in the range of 360 to 600 nm. Nitroaromatic compounds include 4-nitrophenol (4-NP), 4-nitroacetophenone (4-NAP), 4-nitrotoluene (4-NT), 1-bromo-4-nitrobenzene (1-BR-4-NB), p-nitrobenzonitrile (4-NBN), and 4-nitroaniline (4-NA). When 5×10 -3 When the nitroaromatic compounds of M are different, the order of quenching efficiency is 4-NA=4-NP>NB>4-NT>1-BR-4-NB>4-NBN>4-NAP( Figure 6 ).

[0061] In summary, the present invention designs and synthesizes a new type of In-MOF (JOU-36) fluorescent nanomaterial for the detection of nitroaromatic compounds. It not only has a fast detection speed but also exhibits high sensitivity. In addition, the preparation method of the In-MOF (JOU-36) fluorescent nanomaterial is simple, low-cost, low-pollution, and easy to operate.

[0062] The above-described embodiments are merely preferred experimental schemes of the present invention. It should be noted that for those skilled in the art, the experimental schemes may be expressed in different ways, and may be appropriately modified based on the embodiments of the present invention, but all of these are within the scope of protection of the present invention.

Claims

1. A method for preparing an indium-based MOF fluorescent nanomaterial and its application in detecting nitroaromatic compounds, characterized in that: The In-MOF nanomaterial with fluorescence detection performance and the preparation method thereof include the following steps: S1: placing an indium salt in a solvent and stirring it for the first time, then adding H4SFT and stirring it for the second time, further adding nitric acid and stirring it for the third time to obtain a mixed solution; S2: The mixed solution was placed in a pressure-resistant glass bottle for hydrothermal reaction, and a solid product was obtained after treatment, which was labeled as In-MOF (JOU-36): The indium salt is In(NO3)3·4.5H2O, and the nitric acid is HNO3 (65 wt%).

2. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The solvent is N,N-dimethylformamide.

3. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The mass ratio of the indium salt to the solvent is 0.001:

1.

4. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The mass ratio of the indium salt to the H4SFT is 0.8:

1.

5. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The volume ratio of the solvent to the nitric acid is 11:

1.

6. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: In step S1, the first stirring is ultrasonic stirring; And / or, the second stirring comprises: The temperature is 20-30℃, the stirring speed is 130-150r / min, and the stirring time is 25-35min; And / or, the third stirring comprises: The temperature is 20-30°C, the stirring speed is 130-150r / min, and the stirring time is 25-35min.

7. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 6, characterized in that: The ultrasonic stirring time is 25-35 minutes.

8. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 7, characterized in that: The three ultrasonic stirring times are all 30 min.

9. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The solvothermal reaction comprises: The temperature is 100-140°C and the reaction time is 20-30h.

10. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 9, characterized in that: The temperature of the solvent thermal reaction is 120° C., and the reaction time is 24 h.

11. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 1, characterized in that: The treatment includes ultrasonic agitation, centrifugation, washing and drying.

12. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 11, characterized in that: The ultrasonic stirring time is 10-12 minutes.

13. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 11, characterized in that: The centrifugal speed is 8000-9000 r / min, and the time is 5-6 min.

14. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 11, characterized in that: The washing detergent is DMF.

15. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 11, characterized in that: The drying conditions include: The drying temperature is 20-40°C and the drying time is 12-16 hours.

16. The indium-based MOF fluorescent nanomaterial and preparation method according to claim 15, characterized in that: The drying temperature is 30°C.

17. Use of the indium-based MOF fluorescent nanomaterial according to any one of claims 1 to 16.

18. The use of the indium-based MOF fluorescent nanomaterial according to claim 17, characterized in that: The In-MOF (JOU-36) nanomaterial with fluorescence detection performance can be used to detect nitroaromatic compounds.

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