Metal organic framework dual detection fluorescent sensing material, preparation method and application thereof

Abstract

The application discloses a kind of metal organic framework double detection fluorescent sensing materials, which is obtained by the reaction of zirconium-based metal organic framework UiO-66-NH2 and 3-(6-nitro-1,3-dioxo-1H-benzoisoquinoline-2(3H)-yl) propionic acid, and the 3-(6-nitro-1,3-dioxo-1H-benzoisoquinoline-2(3H)-yl) propionic acid is obtained by the reaction of beta-alanine and 4-nitro-1,8 naphthalene dicarboxylic anhydride.The material can realize the double detection of phosphate and hydrogen sulfide, and the concentration change of phosphate in the solution to be measured can be obtained by measuring the fluorescence intensity of the solution at 425nm under the excitation wavelength of 360nm;The concentration change of hydrogen sulfide in the solution to be measured can be obtained by measuring the fluorescence intensity of the solution at 537nm under the excitation wavelength of 435nm, and the detection of the two target detection objects does not interfere with each other, the selectivity and anti-interference ability of the material are strong, the detection sensitivity and accuracy are high, and the detection limit of the two target detection objects is much lower than the concentration range of the two in aquaculture water body.

Description

Technical Field

[0001] This invention relates to the field of analytical chemistry, and in particular to a metal-organic framework dual-detection fluorescence sensing material, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Over the past 30 years, global aquaculture production has grown rapidly at a rate of 8% per year. It is estimated that by 2030, nearly two-thirds of the world's aquatic products will come from aquaculture. To meet the demands of high-density aquaculture, feed and chemicals are needed during the farming process as nutrients and disinfectants for the cultured organisms. Excessive amounts of these substances can not only affect the health of the cultured organisms but also have adverse effects on the surrounding water bodies. Phosphorus, an essential mineral element for fish, negatively impacts the growth of healthy algae when its concentration falls below 0.2 mg / mL, while excessive phosphorus discharge leads to eutrophication. Furthermore, eutrophication also causes changes in hydrogen sulfide levels in the water. Hydrogen sulfide is a soluble, toxic gas with a rotten egg odor; excessive H2S weakens the growth rate, strength, and disease resistance of cultured organisms. The concentration of hydrogen sulfide in aquaculture waters should be strictly controlled below 0.1 mg / L. Therefore, monitoring phosphorus and sulfur levels in aquaculture waters is crucial for both aquaculture and human health.

[0004] To date, researchers have developed various methods for the effective detection of phosphate or hydrogen sulfide. Currently reported methods for detecting PO4... 3- The main methods for determining H₂S include colorimetry, electroanalysis, and fluorescence methods. Among these, fluorescence methods have attracted considerable attention due to their high sensitivity, good selectivity, and simple operation.

[0005] Metal-organic frameworks (MOFs) are porous materials composed of metals and ligands. Due to their porosity, large specific surface area, and diverse structures and functions, they hold great promise for applications in smart sensing. In recent years, some fluorescent sensors based on MOFs that are sensitive to phosphate and hydrogen sulfide have been developed; however, to date, no fluorescent sensing materials have been reported that achieve dual detection of phosphate and hydrogen sulfide. Summary of the Invention

[0006] In view of this, the present invention provides a metal-organic framework dual-detection fluorescent sensing material, its preparation method and its application, which realizes dual detection of phosphate and hydrogen sulfide by a single fluorescent sensing material, and has high anti-interference, high selectivity and high detection sensitivity.

[0007] In a first aspect, the present invention provides a metal-organic framework dual-detection fluorescent sensing material, which is obtained by reacting zirconium-based metal-organic framework UiO-66-NH2 with 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid. The structural formula of the 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid is shown in Formula (I), which is obtained by reacting β-alanine with 4-nitro-1,8-naphthalenedicarboxylic anhydride.

[0008]

[0009] Secondly, the present invention provides a method for preparing a metal-organic framework dual-detection fluorescence sensing material, comprising the following steps:

[0010] Step S1: Under the protection of an inert gas, 4-nitro-1,8-naphthalenedic anhydride and β-alanine are heated and reacted in an organic solvent. The product after the reaction is cooled and crystallized, filtered and dried to obtain 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid.

[0011] Step S2: Under the protection of an inert gas, the 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid obtained in step S1 is dissolved in an organic solvent and stirred at low temperature. Then, a zirconium-based metal-organic framework UiO-66-NH2 is added to it, and after mixing evenly, the mixture is stirred at room temperature. The resulting product is centrifuged, washed, and dried to obtain the final product.

[0012] Preferably, in step S1, the inert gas includes nitrogen, argon, or a mixture of both; the molar ratio of 4-nitro-1,8-naphthalene anhydride and β-alanine is 1:1-1.5; the organic solvent is ethanol; the heating reaction temperature is 80-90℃, and the reaction time is 4-6h.

[0013] Preferably, in step S1, the cooling crystallization is performed by placing the product cooled to room temperature in an ice-water bath for full crystallization; the drying is performed by vacuum drying at room temperature to constant weight.

[0014] Preferably, in step S2, the inert gas includes nitrogen, argon, or a mixture of both; the molar ratio of UiO-66-NH2 and 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid is 1:35-45; the organic solvent is N,N-dimethylformamide; preferably, the ratio of 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid to the organic solvent is 150mg:10-30mL.

[0015] Preferably, in step S2, the stirring temperature at low temperature is -5 to 5°C, and the stirring time is 20-40 min; the reaction time at room temperature after uniform mixing is 20-28 h; the washing is performed using deionized water; and the drying is performed at room temperature under vacuum until constant weight.

[0016] The zirconium-based metal-organic framework UiO-66-NH2 described in this invention can be synthesized using conventional methods in the art, or it can be a commercially available product.

[0017] In some specific embodiments of the present invention, the preparation method of the zirconium-based metal-organic framework UiO-66-NH2 is as follows:

[0018] 2-Aminoterephthalic acid, zirconium tetrachloride, and benzoic acid were dissolved in an organic solvent, concentrated hydrochloric acid was added, and the mixture was stirred until homogeneous. The mixture was then transferred to a Teflon-lined stainless steel reactor and reacted at 115-125°C for 45-55 hours. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, and washed 2-5 times with organic solvent and deionized water, respectively. Finally, the mixture was dried overnight under vacuum to obtain a zirconium-based metal-organic framework UiO-66-NH2.

[0019] Thirdly, the present invention provides the application of the above-mentioned metal-organic framework dual-detection fluorescent sensing material or the metal-organic framework dual-detection fluorescent sensing material prepared by the above-mentioned preparation method in the dual detection of phosphate and hydrogen sulfide.

[0020] Fourthly, the present invention provides a method for dual detection of phosphate and hydrogen sulfide, comprising the following steps:

[0021] Step S1: Prepare the stock solution of the above metal-organic framework dual-detection fluorescent sensing material;

[0022] Step S2: Mix the mother liquor of the metal-organic framework dual-detection fluorescent sensing material with the test solution to obtain a mixed solution;

[0023] Step S3: Measure the fluorescence intensity of the mixture at 425 nm under an excitation wavelength of 360 nm, and calculate the phosphate concentration in the test solution based on the linear curve of fluorescence intensity at 425 nm and phosphate concentration; Measure the fluorescence intensity of the mixture at 537 nm under an excitation wavelength of 435 nm, and calculate the hydrogen sulfide concentration in the test solution based on the linear curve of fluorescence intensity at 537 nm and hydrogen sulfide concentration.

[0024] Preferably, in step S1, the solvent of the mother liquor of the metal-organic framework dual-detection fluorescent sensing material is a Tris buffer solution with pH = 7.4.

[0025] Preferably, in step S2, the concentration of the metal-organic framework dual-detection fluorescent sensing material in the mixture is 40-60 μg / mL.

[0026] The zirconium-based metal-organic framework UiO-66-NH2 in the metal-organic framework dual-detection fluorescence sensing material of this invention contains phosphate response sites. During phosphate detection, the two can form Zr-OP bonds, weakening the effective charge transfer from the ligand to the metal, thus enhancing the fluorescence of the sensing material at 425 nm. During hydrogen sulfide detection, the nitro group in the NDBPA framework structure, which is functionalized with carboxyl groups, is reduced to an amino group, resulting in fluorescence enhancement at 537 nm based on intramolecular charge transfer. The fluorescence intensity changes at 435 nm and 537 nm indicate the changes in phosphate and hydrogen sulfide levels in the aqueous system, respectively.

[0027] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0028] (1) The present invention prepared UiO-66-NH2@NDBPA metal-organic framework fluorescent sensing material by a convenient post-coordination modification method;

[0029] (2) This invention is the first to realize the dual detection of phosphate and hydrogen sulfide by a single material in a water system. It can generate different signal responses under different excitation lengths, and the detection of the two does not interfere with each other.

[0030] (3) The metal-organic framework dual-detection fluorescent sensing material prepared in this invention has strong selectivity and anti-interference ability when detecting phosphate or hydrogen sulfide, and has high detection sensitivity and accuracy. Moreover, the detection limit of the material for the two target analytes is much lower than the concentration range of the two in aquaculture water. For the detection of phosphate, it has a good linear relationship in the range of 0.1-100 μM, with a detection limit as low as 45 nM. For the detection of hydrogen sulfide, it has a good linear relationship in the range of 0.1-900 μM, with a detection limit as low as 0.12 μM. Attached Figure Description

[0031] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0032] Figure 1 The 1H NMR spectrum of 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid (NDBPA) synthesized in Example 1 of this invention;

[0033] Figure 2 X-ray diffraction patterns of UiO-66-NH2 powder (a) and UiO-66-NH2@NDBPA powder (b) prepared in Example 1 of the present invention, and powder (c) of UiO-66-NH2@NDBPA after soaking in Tris buffer for 24 hours and drying.

[0034] Figure 3 Scanning electron microscope (SEM) images of UiO-66-NH2 (Figure A) and UiO-66-NH2@NDBPA (Figure B) prepared in Example 1 of this invention;

[0035] Figure 4 The UV-Vis absorption spectra of UiO-66-NH2 (a), NPDA (b), and UiO-66-NH2@NDBPA (c) in Example 1 of this invention are shown.

[0036] Figure 5 Fourier transform infrared spectra of NPDA (a), β-alanine (b), NDBPA (c), 2,5-dihydroxyterephthalic acid (d), UiO-66-NH2 (e), and UiO-66-NH2@NDBPA (f) in Example 1 of the present invention.

[0037] Figure 6 UiO-66-NH2@NDBPA and different concentrations of PO4 in Example 2 of this invention 3- Fluorescence spectrum of the response;

[0038] Figure 7 The relative fluorescence intensity (F425) of UiO-66-NH2@NDBPA in Example 2 of this invention is compared with that of PO4. 3- Linear relationship of concentration;

[0039] Figure 8 UiO-66-NH2@NDBPA and different concentrations of HS in Example 2 of this invention - The fluorescence response spectrum;

[0040] Figure 9 The relative fluorescence intensity (F537) of UiO-66-NH2@NDBPA in Example 2 of this invention is compared with HS. - Linear relationship of concentration;

[0041] Figure 10 This is a selectivity graph of UiO-66-NH2@NDBPA for phosphate at 425 nm in Example 3 of the present invention. The vertical axis represents the change in fluorescence intensity, and the horizontal axis represents the number of each substance.

[0042] Figure 11 The UiO-66-NH2@NDBPA of Example 4 of this invention has a high HS content at 537 nm. - The selectivity plot shows the change in fluorescence intensity on the vertical axis and the number of each substance on the horizontal axis. Detailed Implementation

[0043] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0044] In this embodiment of the invention, PO4 3- Na + Cd 2+ Fe 2+ Al 3+ Ca 2+ Ag + ,Br - CO3 2- NO3 - SO3 2- HSO3 - S2O8 2- ,ClO - Cys (Cysteine), ATP (Adenosine triphosphate), AA (Ascorbic acid), and HS - The standard solutions were prepared by dissolving Na3PO4·12H2O, NaCl, Cd(NO3)2, FeCl2·4H2O, Al(NO3)3·6H2O, CaCl2, AgNO3, KBr, Na2CO3, NaNO3, Na2SO3, NaHSO3, Na2S2O8, NaClO, Cys, ATP, AA, and NaHS in water and then making up to volume in a volumetric flask.

[0045] This invention does not impose any special restrictions on the source of any reagents; commercially available products well known to those skilled in the art can be used.

[0046] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0047] Example 1: Preparation of UiO-66-NH2@NDBPA

[0048] (I) Preparation of UiO-66-NH2

[0049] 2-Aminoterephthalic acid (59 mg), zirconium tetrachloride (77 mg), and benzoic acid (0.61 g) were dissolved in 6 mL of DMF, and 55 μL of concentrated hydrochloric acid was added. After stirring thoroughly, the mixture was transferred to a Teflon-lined stainless steel reactor and reacted at 120 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, and washed 3-5 times with DMF and deionized water. Finally, the sample was dried overnight under vacuum to obtain UiO-66-NH2.

[0050] (II) Synthesis of NDBPA

[0051] Under N2 protection, 4-nitro-1,8-naphthalenediic anhydride (0.2432 g, 1 mmol, NPDA) and β-alanine (0.1069 g, 1.2 mmol) were added to 20 mL of anhydrous ethanol and stirred until homogeneous. The reaction was carried out at 85 °C for 6 h to obtain the crude product. After cooling the crude product to room temperature, it was poured into 200 mL of ice water for complete crystallization, then filtered and dried under vacuum at room temperature. The product was 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid, denoted as NDBPA. The 1H NMR spectrum of NDBPA is shown below. Figure 1 As shown. 1 H NMR (400MHz, DMSO): δ12.42(s,1H),8.69(d,1H),8.60(dd,2H),8.54(d,1H),8.10-8.06(m,1H),4.28-4.24(m,2H),2.64-2.60(m,2H).

[0052] (III) Preparation of UiO-66-NH2@NDBPA

[0053] Under N2 protection, NDBPA (146.5 mg, 0.48 mmol) was dissolved in 10 mL of DMF. After incubating in an ice bath for 30 min, UiO-66-NH2 (20 mg, 0.012 mmol) dispersed in 10 mL of DMF was added dropwise to the solution. After stirring until homogeneous, the solution was stirred at room temperature for 24 h and washed with deionized water. The solution was then dried under vacuum at room temperature to obtain UiO-66-NH2@NDBPA.

[0054] The UiO-66-NH2 and UiO-66-NH2@NDBPA prepared in this embodiment were characterized in a series of ways. Figure 2 The X-ray diffraction patterns of the UiO-66-NH2 powder and UiO-66-NH2@NDBPA powder prepared in Example 1 of this invention, as well as the powder of UiO-66-NH2@NDBPA after soaking in Tris buffer for 24 hours and drying, show that the framework structure of the metal-organic framework UiO-66-NH2 remains unchanged before and after NDBPA modification. At the same time, the PXRD pattern of UiO-66-NH2@NDBPA after soaking in the buffer for 24 hours shows almost no change, indicating that the material has good stability in the Tris buffer.

[0055] Figure 3 The SEM images show that the morphology of the metal-organic framework remains unchanged before and after NDBPA modification. Figure 4 The UV-Vis absorption spectroscopy data show that UiO-66-NH2@NDBPA contains both the UV absorption characteristic peaks of UiO-66-NH2 and the UV characteristic absorption peaks of NDBPA, further proving the successful post-modification of UiO-66-NH2 by NDBPA. Figure 5 In the study, the double stretching vibration peaks of C=O in NPDA can be observed at 1776 and 1745 cm⁻¹. -1 After amidation, the corresponding amide C=O characteristic peak appears at 1696 cm⁻¹. -1 and 1653cm -1 This indicates that NDBP was successfully amidated. Compared with the infrared spectrum of UiO-66-NH2, the characteristic peaks of amide were clearly observed in UiO-66-NH2@NDBPA, indicating that the carboxylated NDBPA was successfully modified into the MOF backbone. Meanwhile, Figure 5 NDBPA at 1630cm -1 The disappearance of the characteristic absorption peak of -COOH in the vicinity indicates that NDBPA and UiO-66-NH2 are bound together through coordination interactions.

[0056] Example 2: Application of UiO-66-NH2@NDBPA in the detection of phosphate and hydrogen sulfide.

[0057] (1) Preparation of UiO-66-NH2@NDBPA mother liquor

[0058] 2.5 mg of UiO-66-NH2@NDBPA prepared in Example 1 above was dispersed in 5 mL of water and ultrasonically dispersed to obtain a UiO-66-NH2@NDBPA mother liquor of 500 μg / mL.

[0059] (2) Detection of phosphate ions:

[0060] Add 200 μL of UiO-66-NH2@NDBPA stock solution and different volumes of Na3PO4·12H2O standard solution to the buffer solution, then dilute the detection system to 2 mL (pH = 7.4) with deionized water to allow the PO4 content to rise. 3- The final concentration of the reagent was 0-100 μM, and the final concentration of UiO-66-NH2@NDBPA was 50 μg / mL. After complete reaction, the fluorescence emission spectrum was measured at an excitation wavelength of 360 nm, and fluorescence in the wavelength range of 380-600 nm was collected. A fluorescence intensity-phosphate concentration relationship graph was plotted with fluorescence intensity at 425 nm as the ordinate and phosphate concentration as the abscissa, and a linear curve was obtained by fitting the graph.

[0061] y1=103.2828x1+1847.3995,R1 2 =0.9931 (x1: 0.1~35μM); y2=33.2437x2+3894.4525, R2 2 =0.9941 (x2: 35~100μM). y1, y2 are the fluorescence intensities at 425nm, and x1, x2 are the phosphate concentrations.

[0062] Figure 6 UiO-66-NH2@NDBPA with different concentrations of PO4 3- The fluorescence spectrum of the response shows that the fluorescence intensity at 425 nm gradually increases with the continuous increase of phosphate concentration. Figure 7 The relative fluorescence intensity (F425) of UiO-66-NH2@NDBPA and PO4 3- The linear relationship curves of the concentration show that the fluorescence intensity at 425 nm has a clear linear relationship with the phosphate concentration in the ranges of 0.1–35 μM and 35–100 μM, with a detection limit as low as 45 nm.

[0063] Take 200 μL of UiO-66-NH2@NDBPA stock solution, mix it evenly with a certain volume of actual water sample to be tested, add it to the buffer solution, and then make up to 2 mL with deionized water. Measure the fluorescence emission spectrum at an excitation wavelength of 360 nm and obtain the fluorescence intensity at 425 nm. By referring to the linear curve of fluorescence intensity-phosphate concentration, the phosphate concentration in the detection system can be obtained.

[0064] (3) Detection of hydrogen sulfide

[0065] Add 200 μL of UiO-66-NH2@NDBPA stock solution and different volumes of NaHS solution to the buffer solution, then adjust the final volume of the detection system to 2 mL with deionized water to allow the HS to be absorbed. -The final concentration was 0-1 mM. After complete reaction, the fluorescence emission spectrum was measured at an excitation wavelength of 435 nm, and fluorescence in the wavelength range of 470-700 nm was collected. A fluorescence intensity-hydrogen sulfide concentration relationship was plotted with fluorescence intensity at 537 nm as the ordinate and hydrogen sulfide concentration as the abscissa, and a linear curve was obtained by fitting: y = 5.346x + 254.4259, R0 2 =0.9910 (X: 0.1~900μM), y is the fluorescence intensity at 537nm, and x is the HS-C. - The concentration of hydrogen sulfide. Hydrogen sulfide ionizes in water to form H₂S. - and H + Therefore, through HS - The detection can achieve the determination of hydrogen sulfide concentration in water.

[0066] Figure 8 UiO-66-NH2@NDBPA with different concentrations of HS - The fluorescence response spectrum shows that the fluorescence intensity at 537 nm gradually increases with increasing NaHS concentration. For example... Figure 9 As shown, the relative fluorescence intensity (F537) of UiO-66-NH2@NDBPA is compared with that of HS. - The linear relationship between concentration and fluorescence intensity shows that the fluorescence intensity at 537 nm is related to HS. - The concentration exhibits a clear linear relationship in the range of 0.1–900 μM, with a detection limit as low as 0.12 μM.

[0067] Take 200 μL of UiO-66-NH2@NDBPA stock solution, mix it evenly with a certain volume of actual water sample to be tested, add it to the buffer solution, and then make up to 2 mL with deionized water. Measure the fluorescence emission spectrum at an excitation wavelength of 435 nm to obtain the fluorescence intensity at 537 nm. By comparing the fluorescence intensity-hydrogen sulfide concentration linear curve, the concentration of hydrogen sulfide in the detection system can be obtained.

[0068] Example 3: Anti-interference detection of phosphate by UiO-66-NH2@NDBPA

[0069] Take several portions of 200 μL UiO-66-NH2@NDBPA stock solution, and then add a certain volume of PO4 sequentially. 3- Na + Cd 2 + Fe 2+ Al 3+ Ca 2+ Ag + ,Br - CO3 2- NO3 - SO32- HSO3 - S2O8 2- ,ClO - Cys, ATP, AA, HS - Standard solutions (numbered sequentially from 1 to 18, such as PO4) 3- Numbered 1), the total volume of the detection system was 2 mL, and the concentration of all interfering substances in the final system was 500 μM, PO4. 3- The concentration of UiO-66-NH2@NDBPA was 100 μM. Its fluorescence emission spectrum was measured at an excitation wavelength of 360 nm. The fluorescence intensity at 425 nm was used as the criterion to determine the effect of UiO-66-NH2@NDBPA on phosphate.

[0070] like Figure 10 As shown, in the selective detection of phosphate, the change in fluorescence intensity at 425 nm indicates that UiO-66-NH2@NDBPA has good selectivity for phosphate.

[0071] Example 4: Anti-interference detection of hydrogen sulfide by UiO-66-NH2@NDBPA

[0072] Take several portions of 200 μL UiO-66-NH2@NDBPA stock solution, and then add a certain volume of HS sequentially. - Na + Cd 2+ Fe 2+ Al 3+ Ca 2+ Ag + ,Br - CO3 2- NO3 - SO3 2- HSO3 - S2O8 2- ,ClO - Cys, ATP, AA, PO4 3- Standard solutions (numbered sequentially from 1 to 18, such as HS) - Numbered 1), the total volume of the detection system is 2 mL, and the concentration of all interfering substances in the final system is 1 mM, HS - The concentration of the reagent was 500 μM. After the reaction, the fluorescence emission spectrum was measured at an excitation wavelength of 435 nm. The effect of UiO-66-NH2@NDBPA on phosphate was judged based on the fluorescence intensity at 537 nm.

[0073] like Figure 11As shown, the fluorescence intensity change at 537 nm indicates that UiO-66-NH2@NDBPA exhibits good selectivity for hydrogen sulfide.

[0074] Example 5: Spiked Recovery Determination of UiO-66-NH2@NDBPA Fluorescence Sensor

[0075] Water samples were taken from laboratory water. Several 200 μL portions of UiO-66-NH2@NDBPA stock solution were taken, and then different volumes of Na3PO4 and NaHS standard solutions were added to bring the volume to 2 mL. After the reaction was complete, the fluorescence spectrum was measured. The concentrations of phosphate and hydrogen sulfide in the response and the corresponding recovery rates were calculated based on the linear curve, as shown in Tables 1 and 2.

[0076] Table 1. Detection results of phosphate in water samples

[0077]

[0078] Table 2. Detection results of hydrogen sulfide in water samples

[0079]

[0080] As shown in Tables 1 and 2, the recovery rate for phosphate detection was 99.32%–99.81%, with a relative standard deviation (RSD) of 0.1%–0.2%. For hydrogen sulfide detection, the recovery rate was 98.62%–101.95%, with an RSD of 0.2%–0.4%. This indicates that UiO-66-NH2@NDBPA has good accuracy in detecting these two target analytes in actual water bodies.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metal-organic framework dual-detection fluorescence sensing material, characterized in that, It is obtained by reacting zirconium-based metal-organic framework UiO-66-NH2 with 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid, the structural formula of which is shown in Formula (I), which is obtained by reacting β-alanine with 4-nitro-1,8-naphthalenedicarboxylic anhydride; Equation (I).

2. A method for preparing a metal-organic framework dual-detection fluorescence sensing material, characterized in that, Includes the following steps: Step S1: Under the protection of an inert gas, 4-nitro-1,8-naphthalenedicarboxylic anhydride and β-alanine are heated and reacted in an organic solvent. The product after the reaction is cooled and crystallized, filtered and dried to obtain 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid. Step S2: Under the protection of an inert gas, the 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid obtained in step S1 is dissolved in an organic solvent and stirred at low temperature. Then, a zirconium-based metal-organic framework UiO-66-NH2 is added to it, and after mixing evenly, the mixture is stirred at room temperature. The resulting product is centrifuged, washed, and dried to obtain the final product.

3. The method for preparing the metal-organic framework dual-detection fluorescence sensing material as described in claim 2, characterized in that, In step S1, the inert gas includes nitrogen, argon, or a mixture of both; the molar ratio of 4-nitro-1,8-naphthalenedicarboxylic anhydride and β-alanine is 1:1-1.5; the organic solvent is ethanol; the heating reaction temperature is 80-90 °C, and the reaction time is 4-6 h; the cooling crystallization involves placing the product cooled to room temperature in an ice-water bath for full crystallization; and the drying involves vacuum drying at room temperature to constant weight.

4. The preparation method of the metal-organic framework dual-detection fluorescence sensing material as described in claim 2, characterized in that, In step S2, the inert gas includes nitrogen, argon, or a mixture of the two; the molar ratio of UiO-66-NH2 and 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid is 1:35-45; and the organic solvent is N,N-dimethylformamide.

5. The method for preparing the metal-organic framework dual-detection fluorescence sensing material as described in claim 4, characterized in that, The ratio of 3-(6-nitro-1,3-dioxo-1H-benzisoquinoline-2(3H)-yl)propionic acid to organic solvent is 150 mg: 10-30 mL.

6. The method for preparing the metal-organic framework dual-detection fluorescence sensing material as described in claim 2, characterized in that, In step S2, the stirring temperature at low temperature is -5~5℃, and the stirring time is 20-40 min; the stirring reaction time at room temperature after uniform mixing is 20-28 h; the washing is performed using deionized water; and the drying is performed by vacuum drying at room temperature to constant weight.

7. The method for preparing the metal-organic framework dual-detection fluorescence sensing material as described in claim 2, characterized in that, The preparation method of the zirconium-based metal-organic framework UiO-66-NH2 is as follows: 2-Aminoterephthalic acid, zirconium tetrachloride, and benzoic acid were dissolved in an organic solvent, concentrated hydrochloric acid was added, and the mixture was stirred until homogeneous. The mixture was then transferred to a Teflon-lined stainless steel reactor and reacted at 115-125℃ for 45-55 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, and washed 2-5 times with organic solvent and deionized water, respectively. Finally, the mixture was dried overnight under vacuum to obtain a zirconium-based metal-organic framework UiO-66-NH2.

8. The application of the metal-organic framework dual-detection fluorescent sensing material as described in claim 1 or the metal-organic framework dual-detection fluorescent sensing material prepared by the preparation method according to any one of claims 2-6 in the dual detection of phosphate and hydrogen sulfide.

9. A method for quantitative detection of phosphate and hydrogen sulfide, characterized in that, Includes the following steps: Step S1: Prepare the metal-organic framework dual-detection fluorescence sensing material according to claim 1 or the metal-organic framework dual-detection fluorescence sensing material prepared by the preparation method according to any one of claims 2-6; Step S2: Mix the mother liquor of the metal-organic framework dual-detection fluorescence sensing material with the test solution to obtain a mixed solution; Step S3: Measure the fluorescence intensity of the mixture at 425 nm under an excitation wavelength of 360 nm, and obtain the phosphate concentration in the test solution based on the linear relationship curve of 425 nm fluorescence intensity-phosphate concentration; Measure the fluorescence intensity of the mixture at 537 nm under an excitation wavelength of 435 nm, and obtain the hydrogen sulfide concentration in the test solution based on the linear relationship curve of 537 nm fluorescence intensity-hydrogen sulfide concentration.

10. The method for quantitative detection of phosphate and hydrogen sulfide as described in claim 9, characterized in that, In step S1, the solvent of the mother liquor of the metal-organic framework dual-detection fluorescent sensing material is Tris buffer solution with pH=7.

4.

11. The method for quantitative detection of phosphate and hydrogen sulfide as described in claim 9, characterized in that, In step S2, the concentration of the metal-organic framework dual-detection fluorescent sensing material in the mixture is 40-60 μg / mL.

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