Terbium Complex of Ternary Aromatic Acid as a Multifunctional Fluorescent Probe for Iron Ions, Chromium Ions and Arginine

Abstract

The present invention relates to a ternary aromatic acid terbium complex used as a multifunctional fluorescent probe for Fe 3+ , Cr 2 O 7 2‑ and Arg, and its chemical formula is [Tb 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n , where H 3 NTB is triphenylamine-4,4',4″-tricarboxylic acid. The terbium complex of the present invention, as a fluorescent probe, has obvious recognition effects on Fe 3+ , Cr 2 O 7 2‑ and Arg. After adding 300 μL of Fe ‑3 / Cr 3+ / Cr 2 O 7 2‑ with a concentration of 1×10 ‑3 M, the fluorescence intensity of the terbium complex is significantly quenched, and the fluorescence quenching rates are 94.91% and 97.76% respectively; after adding 300 μL of Arg (1×10 3+ M), the complex shows an obvious fluorescence enhancement phenomenon, and the fluorescence intensity is enhanced by about 4.5 times. Moreover, the recognition effects on Fe 2 O 7 2‑ and Arg are not interfered by other coexisting ions / molecules. When other interfering ions or molecules are added to the solutions containing Fe 3+ , Cr 2 O 7 2‑ and Arg respectively, the fluorescence quenching / enhancement phenomenon is still obvious, indicating that the terbium complex has strong selectivity and specificity for the detection of Fe 3+ , Cr 2 O 7 2‑ and Arg.

Description

Technical Field

[0001] The present invention belongs to the technical field of coordination compounds, and specifically relates to a ternary aromatic acid terbium complex used as a multifunctional fluorescent probe for iron ions (Fe 3+ ), chromium ions (Cr 2 O 7 2- ), and arginine (Arg). The fluorescent probe has potential application prospects in the fields of environmental monitoring and life science. Background Art

[0002] Metal-organic frameworks (MOFs) are organic-inorganic hybrid materials with intramolecular pores formed by the self-assembly of metal ions or metal clusters and coordination groups through coordination bonds [W.B. Liu et al., Cryst. Growth Des. 21 (2021) 5558–5572]. As a new type of organic hybrid material, MOFs have the characteristics of both metal centers and organic linkers and have extensive potential applications in the fields of chemical sensing, gas adsorption and separation, energy storage and conversion, catalysis, drug delivery, etc. [Wei-Yin Sun et al., Cryst. Growth Des. 10 (2018) 1136-1146]. Among them, using luminescent MOFs as highly sensitive fluorescent sensors to detect solvents, organic small molecules, specific metal ions, and metal ions has broad theoretical significance and potential application prospects in the biological and environmental fields.

[0003] Iron is widely distributed in the life system and plays an important role in biological processes such as metabolism, oxygen transport, and the formation of hemoglobin, myoglobin, and cytochromes. However, excessive Fe 3+ can lead to health problems such as hepatitis, heart failure, intellectual disability, decreased immunity, and even cancer [Shubham K et al., Trends in Food Science & Technology (99) 2020 58–75].

[0004] Hexavalent chromium ions, such as dichromate (Cr 2 O 7 2- ) and chromate (CrO 3 2- ), play an important role in industrial fields such as pigment production, metallurgy, printing, and wood preservation; however, chromium is listed as a serious pollutant by the World Health Organization and is harmful to human health. Excessive chromium can cause ulcers, allergic reactions, hereditary genetic defects, and even cancer [M. Tumolo, V., et al., Int. J. Environ. Res. Public Health. 17 (2020) 5438].

[0005] Amino acids (AAs) are the basic units of protein structure and are widely present in foods, blood, and tissues, and are involved in almost all life activities, such as cell division, wound healing, hormone release, etc. Arginine (Arg) is an important natural amino acid and is crucial for mammals and birds. Many studies have shown that arginine can be used as a biomarker to diagnose cysteineuria (also known as "sulfite oxidase deficiency") by detecting the early urinary arginine level in patients [Galkina S et al., Cells 10 (2021) 563].

[0006] Therefore, it is necessary to study a method that can effectively identify Fe 3+ , Cr(VI), and Arg. Traditional detection methods such as atomic absorption spectrometry (AAS), chromatography, inductively coupled plasma atomic emission spectrometry, electrochemistry, and potentiometry require complex instruments, high costs, and long time-consuming, which limit their further application. In contrast, optical detection by fluorescence sensing is simpler, more efficient, and energy-saving [Fan M et al., Inorg. Chem. 60 (2021) 9148–9156]. The Li Xia research group synthesized a series of highly stable Ln-MOFs using a semi-rigid 4-(4-carboxyphenoxy)-isophthalic acid ligand through a solvothermal method, and detected Fe in aqueous phase by fluorescence quenching 3+ [Li Xia et al., CrystEngComm. 22 (2020) 740–750]; The Lei Hou research group synthesized a Cr 3+ fluorescent probe with high sensitivity, high selectivity, and simple regeneration by Eu 2 O 7 2- ions and the organic ligand 3-(1H-pyrazol-3-yl)benzoic acid [Lei Hou et al., Inorg. Chem. (55) 2016 3952-3959]; The He-Rui Wen research group selected a 2',5'-dimethoxytriphenyl-4,4″-dicarboxylic acid ligand to synthesize a series of rare earth metal-organic frameworks, among which Eu-MOF can be used as a ratio fluorescent probe for arginine (Arg) and lysine [He-Rui Wen et al., Inorg. Chem. (61) 2022, 6819–6828].

[0007] In this invention, a water-stable Fe 3+ , Cr 2 O 7 2- and Arg fluorescent probe was successfully prepared using 4,4',4″-tricarboxyaniline, which is a novel fluorescent probe system. A certain amount of Fe was added to the solution of the terbium complex3+ , Cr 2 O 7 2- and Arg, due to the competitive absorption of energy and effective photoinduced electron transfer, its fluorescence intensity is significantly reduced or enhanced. Compared with traditional detection methods, this process is simple to operate, highly selective and sensitive, low in cost, and energy-saving. SUMMARY OF THE INVENTION

[0008] The object of the present invention is to overcome the defects of the prior art and provide a ternary aromatic acid terbium complex as a multifunctional fluorescent probe for iron ions (Fe 3+ ), chromium ions (Cr 2 O 7 2- ) and arginine (Arg).

[0009] The present invention also provides a preparation method and application of the above ternary aromatic acid terbium complex.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] A ternary aromatic acid terbium complex as a multifunctional fluorescent probe for iron ions Fe 3+ , chromium ions Cr 2 O 7 2- and arginine Arg, the chemical formula of the complex is [Tb 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n , where H 3 NTB is triphenylamine-4,4',4″-tricarboxylic acid. The decomposition temperature of the complex is greater than 125 °C; the elemental analysis data are (%, values in parentheses are theoretical values): C. 33.59 (33.61), H. 2.59 (2.56), N. 1.68 (1.71); the main infrared absorption peaks are (unit: cm -1 ): 3373 (br), 1596 (s), 1537 (s), 1507 (s), 1406 (s), 1316 (m), 1280 (m), 1173 (m), 1100 (m), 957 (w), 822 (m), 780 (m), 675 (w), 514 (w).

[0012] The basic structural parameters of the terbium complex are: its crystal belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α = 66.4805 (10) °, β = 80.7997 (9) °, γ = 83.5726 (9) °, The unit cell volume is Tb1 forms an eight - coordinate distorted dodecahedron with O2, O4, O5, O8, O1W, O7a, O2Wa, O2Wb (from three NTB 3- ligands, one acetic acid molecule and four coordinated water molecules). Tb2 forms a nine - coordinate distorted tridecahedron with four oxygen atoms O1, O3, O4, O6 from three NTB 3- ligands, two oxygen atoms O8, O9 of one acetic acid molecule and bridging oxygen atoms O7a, O7b, O2W of three coordinated water molecules.

[0013] A preparation method of the above - mentioned ternary aromatic acid terbium complex, which comprises the following steps:

[0014] 1) Uniformly dissolve triphenylamine - 4,4',4'' - tricarboxylic acid and terbium nitrate in a solvent; the terbium nitrate is Tb(NO 3 ) 3·6H2O ;

[0015] 2) Adjust the pH to 4 - 6, then transfer it to a 25 - mL polytetrafluoroethylene reaction kettle and react at 140 - 160 °C for 48 - 72 h;

[0016] 3) After the reaction, cool it to room temperature at a cooling rate of 4 - 6 °C / h, wash it with distilled water, filter it, and dry it to obtain the complex, which is a light yellow block - shaped crystal.

[0017] Specifically, in step 1), the molar ratio of triphenylamine - 4,4',4'' - tricarboxylic acid to terbium nitrate is 0.05:0.1 - 0.3.

[0018] Specifically, in step 1), the solvent is a mixed solution composed of N,N - dimethylacetamide (DMA) and distilled water.

[0019] Furthermore, the volume ratio of N,N - dimethylacetamide to distilled water is 1:3 - 5.

[0020] Specifically, in step 1), 10 - 12 mL of the solvent is added for every 0.2 mmol of terbium nitrate.

[0021] Specifically, in step 2), HAc with a concentration of 4 - 7 mol / L is used to adjust the pH to 4 - 6.

[0022] Furthermore, in step 3), the drying temperature does not exceed 60 °C (preferably 20 - 60 °C), and the drying time is 10 - 15 h.

[0023] The present invention also provides the above - mentioned ternary aromatic acid terbium complex as a fluorescent probe for detecting Fe 3+ , Cr 2 O 7 2-, applications in arginine for monitoring harmful substances in the environmental and life science fields, such as Fe 3+ , Cr 2 O 7 2- ions and Arg molecules, etc.

[0024] The ternary aromatic acid terbium complex of the present invention forms a three-dimensional network structure. First, Tb1 and Tb2 are bridged by oxygen atoms from coordinated water to form a one-dimensional chain, and adjacent one-dimensional chains are covalently connected by the NTB 3- ligand to form a two-dimensional plane, and adjacent two-dimensional planes are connected by the NTB 3- ligand to form a "flower-shaped" three-dimensional framework.

[0025] Principle description: The present invention selects 4,4',4″-tricarboxyaniline and constructs a complex with a three-dimensional microporous structure with terbium nitrate. At λ ex = 275 nm, the emission spectrum of the terbium complex shows four characteristic emission peaks of Tb(Ⅲ) for 4f charge transitions 5 D 4 → 7 F J (J = 3 - 6), located at 620, 585, 545 and 489 nm respectively. In the terbium complex, the 5 D 4 → 7 F 5 charge transition induced by magnetic dipole shows the strongest emission peak, which can be attributed to the "antenna effect" between the ligand NTB 3- and Tb(Ⅲ), effectively transferring the energy of the NTB 3- ligand to Tb(Ⅲ), thereby enhancing the luminescence intensity.

[0026] Currently, there have been reports on fluorescent probes for cations and anions, amino acids, pesticides, etc. By adding these target substances, the fluorescence intensity of the complex changes significantly, and the presence and concentration of such substances in the system can be qualitatively determined and quantitatively calibrated. The terbium complex used as a multi-functional fluorescent probe for Fe 3+ , Cr 2 O 7 2- and Arg of the present invention is synthesized by the hydrothermal method. Thermogravimetric analysis shows that it has high thermal stability, and the ligand skeleton will collapse only when the temperature is higher than 316℃, which is superior to common fluorescent probe materials. It is worth noting that this invention can be used as a relatively rare fluorescent probe with multi-response functions.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The terbium complex of the present invention, as a fluorescent probe, for Fe3+ , Cr 2 O 7 2- and Arg both have obvious recognition effects. After adding Fe 3+ / Cr 2 O 7 2- , the fluorescence intensities of the terbium complexes are all significantly quenched, and the fluorescence quenching rates are 94.91% and 97.76% respectively; after adding Arg, the complexes show an obvious fluorescence enhancement phenomenon, and the fluorescence intensity is enhanced by about 4.5 times; moreover, the recognition effects on Fe 3+ , Cr 2 O 7 2- and Arg are not interfered by other coexisting ions / molecules; when other interfering ions or molecules are added to the solutions containing Fe 3+ , Cr 2 O 7 2- and Arg respectively, the fluorescence quenching / enhancement phenomenon is still very obvious, indicating that the terbium complexes have specificity for the detection of Fe 3+ , Cr 2 O 7 2- and Arg. In addition, the terbium complexes also have good detection sensitivity and stability for the detection of Fe 3+ , Cr 2 O 7 2- and Arg. Therefore, the terbium complexes of the present invention can be used as multifunctional fluorescent probes for Fe 3+ , Cr 2 O 7 2- and Arg, and are used for the qualitative and quantitative detection of Fe 3+ , Cr 2 O 7 2- and Arg in the environment and organisms, and have potential application prospects in the fields of environmental monitoring and life science. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 For the terbium complexes of the present invention, (a) coordination environment, (b) coordination mode of H 3 NTB, (c) geometric configuration of the Tb(III) atomic center, (d) one-dimensional chain structure of the Tb(III) atom along the c-axis direction, (e) two-dimensional layered structure of the terbium complex, (f) three-dimensional spatial structure of the terbium complex;

[0030] Figure 2Emission spectra of the terbium complex of the present invention dispersed in different metal ion solutions (a) and relative fluorescence intensity of the terbium complex at 545 nm (excitation wavelength: 275 nm) (b);

[0031] Figure 3 Relative fluorescence intensity at 545 nm (excitation wavelength: 275 nm) of the suspension formed by dispersing the terbium complex of the present invention in different anion solutions;

[0032] Figure 4 Relative fluorescence intensity at 545 nm (excitation wavelength: 275 nm) of the suspension formed by dispersing the terbium complex of the present invention in amino acid solutions;

[0033] Figure 5 Relative fluorescence intensity of the terbium complex of the present invention in different metal ion solutions (gray) and relative fluorescence intensity at 545 nm (excitation wavelength: 275 nm) after introducing Fe 3+ ions (black);

[0034] Figure 6 Relative fluorescence intensity of the terbium complex of the present invention in different anion solutions (gray) and relative fluorescence intensity at 545 nm (excitation wavelength: 275 nm) after introducing Cr 2 O 7 2- ions (black);

[0035] Figure 7 Relative fluorescence intensity of the terbium complex of the present invention in different amino acid solutions (gray) and relative fluorescence intensity at 545 nm (excitation wavelength: 275 nm) after introducing Arg (black). Detailed implementation manners

[0036] The technical solutions of the present invention will be further introduced in detail below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto.

[0037] In the following embodiments, unless otherwise specified, the raw materials used are all ordinary commercially available products that can be directly purchased or can be prepared by conventional methods in the art. Room temperature refers to 25 ± 5 °C.

[0038] Example 1 Synthesis of terbium complex

[0039] 0.05 mmol of triphenylamine tricarboxylic acid and 0.2 mmol of terbium nitrate were added to 8 mL of H 2In a mixed solution composed of O and 2 mL of DMA, it was magnetically stirred for 1 h to make it evenly mixed. 6 mol / L HAc was added dropwise to adjust the pH to about 5, and then it was transferred to a 25 mL polytetrafluoroethylene reaction kettle and reacted at 150 °C for 72 h. After the reaction, it was cooled to room temperature at a cooling rate of 5 °C / h, washed with distilled water, filtered, and dried at 60 °C for 12 h to obtain light yellow block crystals, which were terbium complexes with a yield of 63.02% (based on H 3 NTB).

[0040] Example 2 Structure Characterization of Terbium Complex

[0041] At a temperature of 150(2) K, using graphite monochromatic MoKα rays as the excitation light source, single crystal diffraction data was collected by a Bruker Smart CCD X-ray single crystal diffractometer. The crystal structure was analyzed by the direct method, and the crystallographic data was corrected and calculated using the SADABS program and the SHELXTL program. The data was refined using the full matrix least squares method. The detailed crystallographic parameters are listed in Table 1. The crystal structure diagram and three-dimensional structure diagram of the terbium complex [Tb 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n are as shown Figure 1 in the figure.

[0042] Table 1 Crystallographic Data of Terbium Complex with Ternary Aromatic Acid

[0043]

[0044]

[0045] Figure 1 The (a) coordination environment, (b) coordination mode of H 3 NTB, (c) geometric configuration of the Tb(Ⅲ) atom center, (d) one-dimensional chain structure of the Tb(Ⅲ) atom along the c-axis direction, (e) two-dimensional layered structure of the terbium complex, and (f) three-dimensional spatial structure of the terbium complex of the terbium complex are given. It can be seen from Figure 1 that: Tb 3+ forms a binuclear terbium complex through coordination bonds ( Figure 1 in a); Figure 1 in b is the coordination mode of the H 3 NTB ligand: μ 6 -η 1 :η 1 :η 1 :η 1 :η 1 :η 2 ;Figure 1 In c, Tb1 forms an eight - coordinate distorted dodecahedron with O2, O4, O5, O8, O1W, O7a, O2Wa, and O2Wb (from three NTB 3- ligands, one acetic acid molecule, and four coordinated water molecules). Tb2 forms a nine - coordinate distorted tridecahedron with four oxygen atoms O1, O3, O4, O6 from three NTB 3- ligands, two oxygen atoms O8, O9 of one acetic acid molecule, and bridging oxygen atoms O7a, O7b, O2W of three coordinated water molecules. Figure 1 In d, a one - dimensional chain formed by Tb1, Tb2 and the connected oxygen atoms in the c - axis direction. Parallel one - dimensional chains are connected by the ligand NTB 3- to form a two - dimensional planar structure ( Figure 1 in e), and then form a three - dimensional structure ( Figure 1 in f).

[0046] Example 3 Fluorescent properties of terbium complex for Fe 3+ recognition

[0047] All fluorescence tests were completed using an Edinburgh FLS - 980 fluorescence spectrometer. The solid powder samples of the terbium complex were separately dispersed in equal volumes of aqueous solutions containing 10 -3 M of M(Cl) x (M = Cs + , Mn 2+ , Ba 2+ , Ca 2+ , Hg 2+ , Na + , Mg 2+ , Pb 2+ , Ni 2+ , Li + , Co 2+ , Cd 2+ , Al 3+ , Cu 2+ , Zn 2+ and Fe 3+ ) for fluorescence tests. As Figure 2 shown in a and b, when Fe 3+ is added, the terbium complex shows an obvious fluorescence quenching phenomenon, and the quenching rate is as high as 94.91%, while the fluorescence intensity of the terbium complex is less affected by other metal ions.

[0048] To further verify the selectivity of the terbium complex for Fe 3+ ion recognition, an anti - interference experiment was carried out. As Figure 5As shown (the gray bar graph represents the relative fluorescence intensity of the suspension containing the terbium complex and interfering ions, and the black bar graph represents the relative fluorescence intensity of the suspension containing the terbium complex, interfering ions, and Fe 3+ ), introducing Fe 3+ into the suspension containing the terbium complex and the above other metal ions, the corresponding fluorescence intensity is significantly weakened, indicating that the terbium complex has selectivity and anti-interference ability for the recognition of Fe 3+ .

[0049] Example 4 Fluorescent Properties of Terbium Complex for Recognizing Cr 2 O 7 2-

[0050] Similarly, the solid powder samples of the terbium complex were respectively dispersed in equal volumes of aqueous solutions containing 10 -3 M Na n X (X n- = S 2- , F - , NO 3 - , SO 4 2- , ClO 3 - , SCN - , BrO 4 - , Br - , H 2 PO 4 - , WO4 2- , B 4 O 7 2- , S 2 O 8 2- , Cl - , I - , IO 3 - , NO 2 - , CO 3 2- , OH - , HCO 3 - and Cr 2 O 7 2- ) for fluorescence tests, and the results are shown in Figure 3 . It can be seen from Figure 3 that: After adding Cr 2 O 7 2-After the addition of ions, the fluorescence of the terbium complex is almost completely quenched, and the fluorescence quenching efficiency is 97.76%.

[0051] Considering the practical applications of terbium complexes as fluorescent probes in biological and environmental systems, competitive experiments of a series of coexisting anions were studied. The experimental results are as Figure 6 shown. After the addition of the above-mentioned other interfering ions, the fluorescence intensity of the terbium complex decreased significantly ( Figure 6 ), indicating that the recognition of the complex for Cr 2 O 7 2- is not interfered by other anions and has specificity and anti-interference ability.

[0052] Example 5 Fluorescent properties of terbium complex for recognizing arginine Arg

[0053] In addition, solid powder samples of the terbium complex were respectively dispersed in equal volumes of aqueous solutions of amino acids {histidine (His), tyrosine (Tyr), lysine (Lys), glycine (Gly), valine (Val), leucine (Leu), cysteine (Cys), alanine (Ala), asparagine (Asn), threonine (Thr), serine (Ser), methionine (Met), proline (Pro), tryptophan (Trp), glutamine (Gln), phenylalanine (Phe), cystine (Cystine), glutamic acid (Glu), aspartic acid (Asp), arginine (Arg)} with a concentration of 10 -3 for fluorescence testing. The results are shown in Figure 4 . As Figure 4 shown, except for Arg, the influence of other amino acids on the fluorescence intensity of the terbium complex can be ignored. Arg significantly enhances the fluorescence intensity of the terbium complex, and the fluorescence intensity is about 4.5 times that of the blank sample.

[0054] Adding Arg to the suspension containing the terbium complex and the above-mentioned other amino acids results in varying degrees of enhancement of the fluorescence intensity (see Figure 7 ), indicating that the recognition of the terbium complex for Arg has specificity and anti-interference ability.

[0055] In summary, the terbium complex can be used as a multifunctional fluorescent probe to detect Fe 3+ , Cr 2 O 7 2- and Arg.

[0056] Example 6 Comparison of fluorescence selectivity of rare earth complexes in the same series for Fe 3+ , Cr 2 O 7 2- and Arg

[0057] Using 4,4',4″-tricarboxyaniline (H 3 NTB) as a ligand and adopting the same preparation method as in Example 1 above, [Nd 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n , [Eu 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n , {[Gd 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)]·H 2 O]} n , {[Yb 2 (NTB)(OH) 3 (H 2 O)]·H 2 O} n , {[Ho 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)]·H 2 O} n , {[Tm 2 (NTB)(OH) 3 (H 2 O)]·DMA} n , {[Er 2 (NTB)(OH) 3 (H 2 O)]·H 2 O} n and {[Dy 2 (NTB)(OH) 3 (H 2 O)]·4H 2 O} n Nine rare earth complexes of the same series were prepared. Under the same experimental conditions as in Examples 3, 4, and 5, the fluorescence selectivity of this series of rare earth complexes for Fe 3+ , Cr 2 O 7 2- and Arg 的 was compared. The results shown in Table 2 indicate that the terbium complex of the present invention can be used as a multi-responsive fluorescent probe to simultaneously detect Fe 3+ , Cr2 O 7 2- and Arg, and no other rare earth complexes have this function. Experiments have proved that the terbium complex involved in the present invention can be used as Fe 3+ 、Cr 2 O 7 2- and Arg 荧光探针。

[0058] Table 2 Comparison of the fluorescence recognition performance of a series of rare earth complexes for Fe 3+ 、Cr 2 O 7 2- and Arg

[0059]

[0060]

[0061] Note: "-" indicates that the complex cannot be used as a multi-responsive probe to detect Fe 3+ 、Cr 2 O 7 2- and Arg.

[0062] Example 7 Comparison of the sensitivity of different rare earth complexes to the recognition of Fe 3+ 、Cr 2 O 7 2- and Arg

[0063] Sensitivity is one of the important factors for evaluating excellent fluorescent probes. The sensitivity of the terbium complex of the present invention as a fluorescent probe to recognize Fe 3+ 、Cr 2 O 7 2- and Arg molecules was tested by titration experiments respectively. As the concentration of Fe 3+ 、Cr 2 O 7 2- / Arg in the complex suspension increased continuously, the fluorescence intensity decreased continuously (Fe 3+ 、Cr 2 O 7 2- ) / increased (Arg). At low concentrations, the fluorescence intensity showed a linear relationship with the concentration of Fe 3+ 、Cr 2 O 7 2- / Arg. The Fe 3+ 、Cr 2 O 72- and the K sv values of Arg are 2.06×10 3 M -1 , 7.3×10 3 M -1 and 6.0×10 3 M -1 ; the LOD values are 1.07×10 -7 M, 8.17×10 -7 M, 5.8×10 -7 M, and their values are close to the reported 荧光探针数值 . The relevant data are shown in Table 3.

[0064] Table 3 Selectivity comparison of a series of rare earth complexes for Fe 3+ / Cr 2 O 7 2- / Trp fluorescence

[0065]

[0066] Note:

[0067] H 3 L = 2-(6-carboxypyridin-3-yl)terephthalic acid;

[0068] L = 1-(4-carboxybenzyl)-1H-pyrazole-3,5-dicarboxylic acid;

[0069] TDC = 2,5-thiophenedicarboxylic acid;

[0070] BTB = benzene-1,3,5-tribenzoate;

[0071] H 2 L = 2-(1H-1,2,4-triazol-1-yl)terephthalic acid;

[0072] Hpyznpy = 4-((3-(pyrazin-2-yl)-1H-pyrazol-1-yl)methyl)benzoic acid;

[0073] H 3 tcmb = 1,3,5-tris-(carboxymethoxy)benzene;

[0074] H 3TBOT = 2,4,6-tris[1-(3-carboxylphenoxy)ylmethyl]mesitylene;

[0075] H 4 BTEC = 1,2,4,5-benzenetetracarboxylic acid; H3ICA = imidazole units;

[0076] H 2 L = 5-((2-cyano-[1,1-biphenyl]-4-yl)methoxy)isophthalic acid;

[0077] H 3 TATAB = 4,4’,4”-s-triazine--s-triazine-1,3,5-triyltri-m-aminobenzoicacid;

[0078] H 2 pta = 2-(4-pyridyl)-terephthalic acid;

[0079] H 2 DMTP-DC = 2',5"-dimethoxytriphenyl-4,4"-dicarboxylic acid;

[0080] H 3 NTB = 4,4',4"-nitrilotrisbenzoic acid.

[0081] The complexes reported in the literature for Fe 3+ / Cr 2 O 7 2- / Arg only have a single fluorescence recognition function, while the terbium complexes of the present invention have the multifunctional characteristics of selectively recognizing Fe 3+ 、Cr 2 O 7 2- and Arg, and exhibit a lower detection limit; Structural analysis shows that the terbium complexes of the present invention have the characteristics of simple structure and mild synthesis conditions.

[0082] The present invention is used as Fe 3+ 、Cr 2 O 7 2-The terbium complex of the Arg fluorescent probe and its preparation method have been described through specific examples. Those skilled in the art can draw on the content of the present invention and appropriately change raw materials, process conditions and other aspects to achieve corresponding other purposes. Any relevant changes do not depart from the content of the present invention. All similar substitutions and modifications are obvious to those skilled in the art and are regarded as being included within the scope of the present invention.

Claims

1. A ternary terbium complex of aromatic acid used as a multifunctional fluorescent probe for Fe 3+ , Cr 2 O 7 2- and arginine It is characterized in that The chemical formula of the complex is [Tb 2 (NTB)(CH 3 COO)(OH) 2 (H 2 O)] n , where H 3 NTB is triphenylamine-4,4',4″-tricarboxylic acid; The crystal belongs to the triclinic system, and the space group is P -1. The unit cell parameters are: α α = 66.4805(10)˚, β = 80.7997(9)˚, γ = 83.5726(9)˚, a a = 7.2340(2) Å, b b = 15.2266(4) Å, c c = 15.4251(4) Å.

2. The preparation method of the ternary aromatic acid terbium complex according to claim 1, It is characterized in that comprises the following steps: 1) Uniformly dissolve triphenylamine-4,4',4''-tricarboxylic acid and terbium nitrate in a solvent; 2) Adjust the pH to 4-6, and then react at 140-160 °C for 48-72 h; 3) After the reaction is completed, cool to room temperature, wash with distilled water, filter, and dry to obtain the product; In step 1), the solvent is a mixed solution composed of N,N-dimethylacetamide and distilled water; In step 2), HAc with a concentration of 4-7 mol / L is used to adjust the pH to 4-6.

3. The preparation method of the ternary aromatic acid terbium complex according to claim 2, It is characterized in that in step 1), the molar ratio of triphenylamine-4,4',4''-tricarboxylic acid to terbium nitrate is 0.05:0.1-0.

3.

4. The preparation method of the ternary aromatic acid terbium complex according to claim 2, It is characterized in that the volume ratio of N,N-dimethylacetamide to distilled water is 1:3-5.

5. The preparation method of the ternary aromatic acid terbium complex according to claim 2, It is characterized in that in step 1), 10-12 ml of solvent is added per 0.2 mmol of terbium nitrate.

6. The preparation method of the ternary aromatic acid terbium complex according to claim 2, It is characterized in that in step 3), the drying temperature does not exceed 60 °C, and the drying time is 10-15 h.

7. Use of the ternary aromatic acid terbium complex according to claim 1 in preparing a fluorescent probe for detecting Fe 3+ , Cr 2 O 7 2- , and arginine.

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