MOFs fluorescent probe for hypochlorite detection and synthesis method

Abstract

The invention relates to an MOFs (Metal-Organic Frameworks) fluorescent probe for hypochlorite detection and a synthesis method. The structural formula of the fluorescent probe is shown in the specification. The preparation method comprises the following steps: heating and stirring 2-(6-bromo-1, 3-dioxo-1H-benzo [de] isoquinoline-2 (3H)-yl) terephthalic acid and a mixture of N-hydroxyphthalimide, potassium carbonate and dimethyl sulfoxide to react, and then acidifying, filtering, washing and drying to obtain HIA; the preparation method comprises the following steps: performing ultrasonic dispersion on a mixture of zirconium tetrachloride, formic acid and N, N-dimethylformamide, then performing ultrasonic dispersion on the obtained mixture of HIA and N, N-dimethylformamide, mixing and sealing solutions subjected to two times of ultrasonic dispersion in a reaction kettle, reacting at the temperature of 120-150 DEG C, then performing centrifugal dispersion, collecting precipitates, washing and drying to obtain UiO-66-HIA. The response time of the synthesized UiO-66-HIA to hypochlorite is 5 seconds, and the detection limit is low and is 0.244 mu M.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metal-organic frameworks (MOFs) fluorescent probes, and particularly relates to synthesis of a novel MOFs fluorescent probe containing a naphthalimide fluorophore and a phenolic hydroxyl recognition group and detection of hypochlorite by the MOFs fluorescent probe. In particular, the present application relates to a MOFs fluorescent probe for detecting hypochlorite and a synthesis method thereof. BACKGROUND

[0002] Hypochlorous acid is a strong bactericide and disinfectant. It has been widely used in wastewater treatment, household bleaching and disinfection and purification of drinking water (Anal Chem. 2016; 88(6): 3413.). However, in the process of water treatment, excessive hypochlorite can produce many harmful by-products, such as trihalomethane (THM), which is harmful to the human body (Acta Polytech Hung. 2002; 42(2): 234-43.), and can cause arteriosclerosis, reproductive toxicity, and even cancer. Low levels of hypochlorite cannot effectively kill pathogenic bacteria and viruses, thus bringing many risks. In addition, hypochlorite is a very important reactive oxygen species, which plays an important role in pathological and physiological processes. Abnormal endogenous hypochlorite levels are associated with certain diseases, such as neuronal deformation, cardiovascular disease, lung injury, etc. (Am J Pathol. 2001; 158(3): 879-91.). Therefore, it is of great significance to develop a detection method that can quickly and sensitively detect hypochlorite for human health.

[0003] Common methods for detecting hypochlorite include colorimetric method, electrochemical analysis method (Anal Chem. 2015; 87(21): 10734-7.), chemiluminescence method (Anal Chem. 2014; 86(9): 4528.), high performance liquid chromatography, mass spectrometry and capillary electrophoresis, etc. Among the numerous detection methods, the fluorescent probe detection method has the unique advantages of high selectivity, easy operation, high sensitivity, etc. (Anal Bioanal Chem 411, 1561-1568 (2019).), and can realize rapid detection of hypochlorite. The fluorescent probe for detecting hypochlorite is mainly composed of a fluorescent group, a recognition group and a linking group. In recent years, people have constructed many small molecule fluorescent probes based on rhodamine fluorescent groups, coumarin fluorescent groups, naphthalimide fluorescent groups, etc. However, small molecule probes have certain limitations, such as long response time and low sensitivity. MOFs, as a new type of functional material, have attracted much attention due to their adjustable pore structure, high specific surface area and multifunctionality, and exhibit excellent fluorescence properties, providing an ideal platform for constructing efficient and sensitive fluorescent probes.

[0004] Although MOFs fluorescent probe materials have developed a lot in recent years, there are relatively few MOFs probes for hypochlorite detection, and there are still defects in the rapid response of trace ClO - -BA synthesized by Li et al. has a response time of 15 s and a detection limit of 6.25 μM (Polyhedron 148.000 (2018): 5.); Wu et al. synthesized hydroxyl-functionalized UiO-66-(OH)2, and its derivative aluminum ion modified type Al 3+ @UiO-66-(OH)2 as two kinds of fluorescent probes for ClO - detection in water, UiO-66-(OH)2 has a long response time of 1800 s and a detection limit of 17.5 μM, and the performance of Al 3+ @UiO-66-(OH)2 is improved, with a response time of 30 s and a detection limit of 1.63 μM (J. Solid State Chem. (2022): 305.), but it still does not achieve the rapid response of ClO - with a content of less than 1 μM. SUMMARY

[0005] Based on the above background, the present application aims to solve the problems of low detection sensitivity, long response time and low selectivity of small molecule probes and existing MOFs probes for hypochlorite detection. In the present application, a new naphthalimide ligand 2-(6-hydroxy-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl) terephthalic acid (HIA) is designed and synthesized, and a new MOFs fluorescent probe UiO-66-HIA is directly prepared using the ligand. The preparation strategy directly gives the probe surface more and uniform active sites for hypochlorite detection, thereby achieving excellent sensing performance for hypochlorite, including ultra-fast response time and low detection limit. In addition, the probe can specifically recognize hypochlorite and is not affected by other ion molecules, etc., and has high selectivity. The color change of the probe before and after response can be directly observed under natural light, which makes the probe have good application potential in the fields of environmental monitoring, human safety, etc.

[0006] The technical scheme of the present application is as follows:

[0007] A MOFs fluorescent probe for hypochlorite detection has the following structure:

[0008] UiO-66-HIA;

[0009] The structure of its ligand HIA is as follows:

[0010] .

[0011] The preparation method of the MOFs fluorescent probe for hypochlorite detection of the application comprises the following steps:

[0012] 1) A mixture of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl) terephthalic acid, N-hydroxyphthalimide, potassium carbonate and dimethyl sulfoxide is heated and stirred to react, after the reaction is completed, the reaction solution is poured into cold water, then hydrochloric acid is added for acidification, filtration, washing with distilled water, and then washing with ethanol and dichloromethane and drying to obtain HIA;

[0013] 2) A mixture of zirconium tetrachloride and formic acid is ultrasonically dispersed, then a mixture of HIA obtained in step 1) and N,N-dimethylformamide is ultrasonically dispersed, and the two ultrasonically dispersed solutions are mixed and sealed in a reaction kettle for reaction at a temperature of 120-150 ℃; after the reaction solution is cooled to room temperature, the precipitate is collected by centrifugal dispersion and sequentially washed with N,N-dimethylformamide, anhydrous methanol and acetone, and dried to obtain UiO-66-HIA.

[0014] In the preparation method of the MOFs fluorescent probe for hypochlorite detection, the heating reaction temperature in step 1) is 100-120 ℃, and the reaction time is 6-7 h.

[0015] In the preparation method of the MOFs fluorescent probe for hypochlorite detection, in step 2), the reaction temperature is 120-150 ℃, and the reaction time is 24-30 h; preferably, the ultrasonic dispersion time is 10-30 min each time.

[0016] In the preparation method of the MOFs fluorescent probe for hypochlorite detection, in step 1), the molar ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl) terephthalic acid, N-hydroxyphthalimide and potassium carbonate is 1:(1-1.3):(3-4); and the mass-to-volume ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl) terephthalic acid to dimethyl sulfoxide is (0.05-0.06) g / mL.

[0017] In the preparation method of the MOFs fluorescent probe for hypochlorite detection, in step 2), the molar ratio of zirconium tetrachloride to HIA is 1:(1-1.2); the molar amount-to-volume ratio of zirconium tetrachloride to formic acid is (0.15-0.19) mmol / ml; the molar amount-to-volume ratio of zirconium tetrachloride to the mixed ultrasonic N,N-dimethylformamide is (0.1-0.15) mmol / ml; and the molar amount-to-volume ratio of HIA to the mixed ultrasonic N,N-dimethylformamide is (0.07-0.1) mmol / ml.

[0018] The MOFs fluorescent probe of the application is used for detecting hypochlorite, successfully realizes sensitive response to hypochlorite, including ultrafast response time 5s and low detection limit 0.244 μM. And the color change of the probe before and after response can be directly observed under natural light.

[0019] The specific description is as follows:

[0020] The ligand HIA, zirconium tetrachloride and formic acid are reacted in N,N-dimethylformamide to obtain the novel MOFs fluorescent probe UiO-66-HIA, and the structure is as follows:

[0021] named as UiO-66-HIA;

[0022] The structural formula of the ligand HIA is as follows:

[0023]

[0024] The application provides a preparation method of the novel MOFs fluorescent probe UiO-66-HIA for detecting hypochlorite, and the synthetic route is as shown in the figure: Figure 1

[0025] The preparation is performed according to the following steps:

[0026] Step 1) synthesis of HIA:

[0027] The 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl) terephthalic acid used in the application can be obtained or purchased by any method reported in the prior art, or can be prepared by the method of the embodiment of the application.

[0028] The mixture of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl) terephthalic acid, N-hydroxyphthalimide, potassium carbonate and dimethyl sulfoxide is heated and stirred to react, the reaction is performed at 100-120 ℃ for 6-7 h, after the reaction is completed, the reaction solution is poured into water, then hydrochloric acid is added for acidification, filtration is performed, washing is performed with distilled water, then ethanol and dichloromethane are used for washing and drying to obtain HIA.

[0029] Step 2) synthesis of UiO-66-HIA:

[0030] ​Zirconium tetrachloride, formic acid and a certain amount of N,N-dimethylformamide mixture are ultrasonically dispersed for 10-30 min, then HIA obtained in step 1) is ultrasonically dispersed with a certain amount of N,N-dimethylformamide mixture for 10-30 min, and the two ultrasonically dispersed solutions are mixed and sealed in a reaction kettle, and reacted at 120-150 DEG C for 24-30 h. After the reaction solution is cooled to room temperature, the precipitate is collected by centrifugal dispersion and washed with N,N-dimethylformamide, anhydrous methanol and acetone in sequence, and dried to obtain UiO-66-HIA.

[0031] Further, in the preparation method of the novel MOFs fluorescent probe for detecting hypochlorite, the molar ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de] isoquinolin-2(3H)-yl) terephthalic acid: N-hydroxy phthalimide in step 1) is 1:(1-1.3), potassium carbonate provides an alkaline environment for the reaction, and the molar ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de] isoquinolin-2(3H)-yl) terephthalic acid to potassium carbonate is 1:(3-4).

[0032] The mass-to-volume ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de] isoquinolin-2(3H)-yl) terephthalic acid to dimethyl sulfoxide in step 1) is (0.05-0.06) g / mL.

[0033] The molar ratio of zirconium tetrachloride to HIA in step 2) is 1:(1-1.2); the molar amount and volume ratio of zirconium tetrachloride to formic acid is (0.15-0.19) mmol / ml.

[0034] The molar amount and volume ratio of zirconium tetrachloride to the ultrasonically mixed N,N-dimethylformamide in step 2) is (0.1-0.15) mmol / ml; the molar amount and volume ratio of HIA to the ultrasonically mixed N,N-dimethylformamide is (0.07-0.1) mmol / ml.

[0035] As shown in Figure 2 The powder X-ray diffraction spectra of the synthesized UiO-66-HIA probe and UiO-66 and simulated UiO-66 show that the prepared MOFs have the same structure as UiO-66, and the peaks of the synthesized UiO-66-HIA at 5-10°, 10-15°, about 19°, about 25° and about 43° are basically consistent with the peaks of UiO-66 in this range, which proves the correct synthesis of the structure of UiO-66-HIA.

[0036] The method for detecting hypochlorite by the MOFs fluorescent probe of the application, the UiO-66-HIA probe is mixed with dimethyl sulfoxide, is configured into a probe suspension by ultrasonic, the probe suspension is taken and added into a phosphate buffer solution, then a sodium hypochlorite solution is added, and the change of the fluorescence spectrum with the addition time of hypochlorite is measured; different volumes of the sodium hypochlorite solution are added, so that the concentration of hypochlorite in the system gradually increases, and the relationship between the fluorescence intensity and the concentration of added hypochlorite is calculated; in addition, the probe is not affected by common anions, amino acids and hydrogen peroxide, and the color change of the probe before and after response can be directly observed under natural light, so that the probe has good application potential in the fields of environmental monitoring and human safety.

[0037] Compared with the prior art, the application has the beneficial effects that:

[0038] (I) The novel MOFs fluorescent probe for detecting hypochlorite does not adopt a doping or post-synthesis modification strategy, but directly synthesizes a new ligand with a fluorophore and a recognition group. 4+ Due to the coordination of the Zr

[0039] (II) The synthesized UiO-66-HIA has a fast response time of 5s to hypochlorite and a low detection limit of 0.244 μM.

[0040] (III) The synthesized UiO-66-HIA has high selectivity to hypochlorite and is not affected by other anions. 2- , Br - , Cl - , F - , H2PO4 - , PO4 3- , CH3COO - , NO3 - , NO2 - , HCO3 - , CO3 2- , SO4 2- , SO3 2- , OH -, Glu, Pro, L-Cys, H2O2 do not respond, and even in the presence of these interferents, the probe can have a clear response to hypochlorite, has strong specificity and anti-interference ability, the color change of the probe before and after response can be directly observed under natural light, therefore, the UiO-66-HIA prepared in the application has good application potential in the monitoring of hypochlorite in water body environments such as lake water, rainwater and the like and the field of human safety and the like.

[0041] (Four) the UiO-66-HIA synthesized in the application can realize the "on-off type" detection of hypochlorite, as a new type of MOFs fluorescent probe, can promote the development of MOFs fluorescent probes in the field of hypochlorite detection. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 Synthesis route map of UiO-66-HIA

[0043] Figure 2 PXRD map of UiO-66-HIA, UiO-66 and UiO-66 simulation

[0044] Figure 3 Nuclear magnetic resonance hydrogen spectrum map of HIA

[0045] Figure 4 Fluorescence spectrum and fluorescence intensity-time change line graph of UiO-66-HIA after adding hypochlorite

[0046] Figure 5 Hypochlorite addition concentration-fluorescence intensity change line graph and fitted hypochlorite concentration-fluorescence intensity graph

[0047] Figure 6 Selectivity and anti-interference experiment graph of UiO-66-HIA

[0048] Figure 7 Phosphate buffer solution (left) and phosphate buffer solution (right) of 20 μg / mL UiO-66-HIA+200 μM hypochlorite of 20 μg / mL UiO-66-HIA under sunlight color change graph DETAILED DESCRIPTION

[0049] The application proposes a preparation method of a new type of MOFs fluorescent probe UiO-66-HIA for detecting hypochlorite, and the synthesis route is as follows Figure 1As shown: first 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid and N-hydroxyphthalimide, potassium carbonate in dimethyl sulfoxide acidification to get HIA; finally zirconium tetrachloride, formic acid, HIA in N,N-dimethylformamide to get UiO-66-HIA.

[0050] Example 1: Synthesis of MOFs fluorescent probe UiO-66-HIA

[0051] 1) Synthesis of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid: 2-amino terephthalic acid (3.62 g, 20 mmol) and 50 ml of anhydrous methanol were added to a round-bottom flask, 10 ml of triethylamine was added under stirring at 0°C, followed by 4-bromo-1,8-naphthalic anhydride (5.54 g, 20 mmol) and 130 ml of anhydrous methanol, and the reaction was carried out at 85°C under nitrogen protection for 24 h. After the reaction was completed, the reaction solution was poured into water and stirred, followed by the addition of hydrochloric acid to acidify until no solid was precipitated, the mixture was filtered, washed with distilled water, and then the precipitate was washed with dichloromethane and dried to obtain 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid solid.

[0052] 2) Synthesis of HIA: 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid (2.80 g, 6.36 mmol), N-hydroxyphthalimide (1.20 g, 7.36 mmol), potassium carbonate (3.52 g, 25.44 mmol) and 50 ml of dimethyl sulfoxide were added to a round-bottom flask, and the reaction was carried out at 100°C for 6.5 h. After the reaction was completed, the reaction solution was poured into water and stirred, followed by the addition of hydrochloric acid to acidify until no solid was precipitated, the mixture was filtered, washed with distilled water, and then the precipitate was washed with ethanol and dichloride and dried to obtain HIA solid. As shown, Figure 3 1 ​H NMR (400 MHz, DMSO-d6) δ 13.31 (s, 2H), 11.99 (s, 1H), 8.63 (d, J = 8.4 Hz, 1H), 8.50 (d, J = 7.2 Hz, 1H), 8.39 (d, J = 8.2 Hz, 1H), 8.19 (d, J = 8.1 Hz, 1H), 8.13 (dd, J = 8.2, 1.8 Hz, 1H), 8.01 (d, J = 1.7 Hz, 1H), 7.83 (t, J = 7.8 Hz, 1H), 7.22 (d, J = 8.2 Hz, 1H).

[0053] 3) Synthesis of UiO-66-HIA: Zirconium tetrachloride (1.0 mmol, 0.23 g) was dissolved in 8 ml of N,N-dimethylformamide, and 6 ml of formic acid was added, and then transferred to a polytetrafluoroethylene-lined reaction vessel, and ultrasonicated for 30 min until a uniform solution was obtained. Subsequently, HIA (1.0 mmol, 0.38 g) was dissolved in 12 ml of N,N-dimethylformamide and ultrasonicated for 30 min until completely dissolved, and then added to the above mixed solution to obtain a uniform mixed solution. Reaction stage, the obtained mixed solution was sealed in a reaction kettle, and reacted at 120°C for 24 h. After the reaction solution was cooled to room temperature, the precipitate was collected by centrifugal dispersion and washed with N,N-dimethylformamide, methanol and acetone in turn. Finally, the obtained solid was dried in a vacuum oven to obtain UiO-66-HIA.

[0054] Example 2: Synthesis of MOFs fluorescent probe UiO-66-HIA

[0055] 1) Synthesis of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid: 2-Aminoterephthalic acid (3.62 g, 20 mmol) and 40 ml of anhydrous methanol were added to a round-bottom flask, and 8.9 ml of triethylamine was added under stirring at 2.5°C, followed by the addition of 4-bromo-1,8-naphthalic anhydride (6.10 g, 22 mmol) and 220 ml of anhydrous methanol, and reacted at 90°C under nitrogen protection for 27 h. After the reaction was completed, the reaction solution was poured into water and stirred, and then acidified with hydrochloric acid until no solid was precipitated, and the mixture was filtered, washed with distilled water, and then the precipitate was washed with dichloromethane and dried to obtain 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid solid.

[0056] 2) Synthesis of HIA: 2-(6-bromo-1,3-dioxo-1 H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid (2.80 g, 6.36 mmol), N-hydroxyphthalimide (1.04 g, 6.36 mmol), potassium carbonate (2.64 g, 19.08 mmol) and 56 ml of dimethyl sulfoxide were added to a round bottom flask and reacted at 1 10 °C for 6 h. After completion of the reaction, the reaction mixture was poured into water and stirred, then acidified with hydrochloric acid until no more solid was precipitated. The mixture was filtered, washed with distilled water, then the precipitate was washed with ethanol and dichloromethane and dried to obtain HIA solid.

[0057] 3) Synthesis of UiO-66-HIA: Zirconium tetrachloride (1.0 mmol, 0.23 g) was dissolved in 10 ml of N,N-dimethylformamide, then 6.66 ml of formic acid was added. The mixture was transferred to a polytetrafluoroethylene-lined reaction vessel and sonicated for 10 min until a homogeneous solution was obtained. Then, HIA (1.2 mmol, 0.45 g) was dissolved in 17.14 ml of N,N-dimethylformamide and sonicated for 10 min until complete dissolution. The solution was added to the previous mixture to obtain a homogeneous solution. The reaction phase was carried out by sealing the resulting mixture in a reactor at 150 °C for 27 h. After cooling the reaction mixture to room temperature, the precipitate was collected by centrifugation and washed sequentially with N,N-dimethylformamide, methanol and acetone. Finally, the resulting solid was dried in a vacuum oven to obtain UiO-66-HIA.

[0058] Example 3: Synthesis of MOFs fluorescent probe UiO-66-HIA

[0059] 1 ) Synthesis of 2-(6-bromo-1,3-dioxo-1 H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid: 2-Aminoterephthalic acid (3.62 g, 20 mmol) and 33.4 ml of anhydrous methanol were added to a round bottom flask, then 8 ml of triethylamine was added with stirring at 5 °C, followed by 4-bromo-1,8-naphthalic anhydride (6.65 g, 24 mmol) and 120 ml of anhydrous methanol. The reaction was carried out at 95 °C under nitrogen for 30 h. After completion of the reaction, the reaction mixture was poured into water and stirred, then acidified with hydrochloric acid until no more solid was precipitated. The mixture was filtered, washed with distilled water, then the precipitate was washed with dichloromethane and dried to obtain 2-(6-bromo-1,3-dioxo-1 H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid solid.

[0060] 2) Synthesis of HIA: 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)terephthalic acid (2.80 g, 6.36 mmol), N-hydroxyphthalimide (1.35 g, 8.26 mmol), potassium carbonate (3.08 g, 22.26 mmol) and 46.67 ml of dimethyl sulfoxide were added to a round bottom flask and reacted at 120 °C for 7 h. After the reaction was completed, the reaction liquid was poured into water and stirred, then hydrochloric acid was added until no solid was precipitated. The mixture was filtered, washed with distilled water, and then the precipitate was washed with ethanol and dichloromethane and dried to obtain HIA solid.

[0061] 3) Synthesis of UiO-66-HIA: Zirconium tetrachloride (1.0 mmol, 0.23 g) was dissolved in 6.67 ml of N,N-dimethylformamide, and 5.27 ml of formic acid was added. After being transferred to a polytetrafluoroethylene-lined reaction vessel, it was ultrasonicated for 20 min until a uniform solution was obtained. Then, HIA (1.11 mmol, 0.42 g) was dissolved in 11.1 ml of N,N-dimethylformamide and ultrasonicated for 20 min until completely dissolved. It was added to the above mixture solution to obtain a uniform mixture solution. In the reaction stage, the obtained mixture solution was sealed in a reaction kettle and reacted at 135 °C for 30 h. After the reaction liquid was cooled to room temperature, the precipitate was collected by centrifugal dispersion and washed with N,N-dimethylformamide, methanol and acetone in turn. Finally, the obtained solid was dried in a vacuum drying box to obtain UiO-66-HIA.

[0062] Example 4: Application of UiO-66-HIA in hypochlorite detection

[0063] Accurately weigh 10 mg of UiO-66-HIA probe and mix with 10 mL of dimethyl sulfoxide, ultrasonicate for 10 min, configure into a 1 mg / mL probe suspension, then remove 100 μL of the probe suspension and dilute to 5 mL with phosphate buffer to ensure that the probe concentration in the solution is maintained at 20 μg / mL. Place the test solution in a cuvette and test its fluorescence spectrum, then add a sodium hypochlorite solution to make the hypochlorite concentration 200 μM, and measure the change of fluorescence spectrum with the addition time of hypochlorite, as shown in Figure 4 As shown in the figure, the probe UiO-66-HIA itself has no fluorescence, and after the addition of hypochlorite, the fluorescence intensity is significantly enhanced at about 553 nm, and the maximum luminescence intensity is reached at 5 s, and the luminescence intensity is basically stable within 5-20 s.

[0064] Add different volumes of sodium hypochlorite solution to the 20 μg / mL probe phosphate buffer to obtain a linear concentration curve of the probe as shown in Figure 5As shown, the fluorescence intensity showed a good linear relationship with the concentration of added hypochlorite in the range of 60-180 μM, and the detection limit of the probe was calculated to be 0.244 μM according to the formula, which was less than 1 μM.

[0065] In addition, the probe is not affected by common anions and amino acids, hydrogen peroxide, etc. Figure 6 As shown, the probe has a good response to S 2- , Br - , Cl - , F - , H2PO4 - , PO4 3- , CH3COO - , NO3 - , NO2 - , HCO3 - , CO3 2- , SO4 2- , SO3 2- , OH - , Glu, Pro, L-Cys and H2O2, and even in the presence of these interferents, the probe still has a clear response to hypochlorite.

[0066] The phosphate buffer solution with 20 μg / mL of UiO-66-HIA was placed in a cuvette (left) and the phosphate buffer solution with 20 μg / mL of UiO-66-HIA + 200 μM hypochlorite was also placed in a cuvette (right), as shown in Figure 7 As shown, the color of the solution can be directly observed to change from light yellow to dark yellow under sunlight, which makes the probe have good application potential in the fields of environmental monitoring, human safety, etc.

[0067] The present application prepares a new MOFs fluorescent probe UiO-66-HIA, and successfully realizes the excellent sensing performance of the probe to hypochlorite, including an ultrafast response time of 5 s and a detection limit of 0.244 μM below 1 μM, in addition, the probe is not affected by other ion molecules, etc. during the process of recognizing hypochlorite, has high selectivity, and the color change of the probe before and after response can be directly observed under natural light, which makes the probe have good application potential in the fields of environmental monitoring, human safety, etc. The UiO-66-HIA synthesized in the present application can realize the "on-off type" detection of hypochlorite, as a new MOFs fluorescent probe, has a positive role in promoting the development of MOFs fluorescent probes in the field of hypochlorite detection.

[0068] The present application is not limited to the above-described specific embodiments, which are merely illustrative and not restrictive, and it is particularly noted that all similar substitutions and modifications apparent to those skilled in the art are considered to be included in the spirit, scope and content of the present application.

Claims

1. A MOF fluorescent probe for hypochlorite detection, characterized in that, Its structure is as follows: UiO-66-HIA; The structural formula of its ligand HIA is as follows: 。 2. The method for preparing the MOFs fluorescent probe for hypochlorite detection according to claim 1, characterized in that, Includes the following steps: 1) 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl) terephthalic acid was heated and stirred with a mixture of N-hydroxyphthalimide, potassium carbonate and dimethyl sulfoxide. After the reaction was completed, the reaction solution was poured into cold water, then acidified with hydrochloric acid, filtered, washed with distilled water, washed with ethanol and dichloromethane and dried to obtain HIA; 2) The mixture of zirconium tetrachloride, formic acid and N,N-dimethylformamide was ultrasonically dispersed. Then, the HIA obtained in step 1) was ultrasonically dispersed with the N,N-dimethylformamide mixture. The solutions of the two ultrasonic dispersions were mixed and sealed in a reaction vessel and reacted at 120~150℃. After the reaction solution was cooled to room temperature, the precipitate was collected by centrifugation and washed with N,N-dimethylformamide, anhydrous methanol and acetone in sequence and dried to obtain UiO-66-HIA.

3. The method for preparing the MOF fluorescent probe for hypochlorite detection as described in claim 2, characterized in that, In step 1), the heating reaction temperature is 100~120 ℃, and the reaction time is 6~7 h.

4. The method for preparing the MOF fluorescent probe for hypochlorite detection as described in claim 2, characterized in that, In step 1), the molar ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl)terephthalic acid: N-hydroxyphthalimide:potassium carbonate is 1:(1~1.3):(3~4); the mass-to-volume ratio of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl)terephthalic acid:dimethyl sulfoxide is (0.05~0.06) g / mL.

5. The method for preparing the MOF fluorescent probe for hypochlorite detection as described in claim 2, characterized in that, In step 2), the ultrasonic dispersion time is 10-30 minutes each time.

6. The method for preparing the MOF fluorescent probe for hypochlorite detection as described in claim 2, characterized in that, In step 2), the reaction is carried out at 120~150 ℃ for 24~30 h.

7. The method for preparing the MOF fluorescent probe for hypochlorite detection as described in claim 2, characterized in that, In step 2), the molar ratio of zirconium tetrachloride to HIA is 1:(1-1.2); the molar and volume ratio of zirconium tetrachloride to formic acid is (0.15~0.19) mmol / ml; the molar and volume ratio of zirconium tetrachloride to N,N-dimethylformamide mixed with ultrasound is (0.1~0.15) mmol / ml; and the molar and volume ratio of HIA to N,N-dimethylformamide mixed with ultrasound is (0.07~0.1) mmol / ml.

8. The MOF fluorescent probe of claim 1 is used to detect hypochlorite.

9. The MOF fluorescent probe of claim 1 is used to detect hypochlorite ions, and successfully achieves a sensitive response to hypochlorite ions, including an ultrafast response time of 5 s and a low detection limit of 0.244 μM.

10. The MOF fluorescent probe of claim 1 is used to detect hypochlorite, and the color change before and after the probe response can be directly observed under natural light.

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