A water-soluble carbohydrazide derivative, a preparation method thereof, and a method for detecting ions or amino acids

Abstract

The present application relates to a kind of water-soluble carbohydrazide derivative and its preparation method, the method for detecting ion or amino acid, belong to organic small molecule probe technical field.The present application introduces different pyridyl on the hydrazine group of carbohydrazide, obtains a kind of pyridyl substituted carbohydrazide derivative.Compared with existing carbohydrazide compound, the recognition function of pyridyl substituted carbohydrazide derivative provided by the present application has been expanded and regulated, can be used for Cu 2+ , Hg 2+ , Ca 2+ , Cd 2+ , Zn 2+ , AcO ‑ , HSO4 ‑ And glutamic acid (Glu) / L-Asp, lysine (Lys) / arginine (Arg) recognition detection.The water-soluble carbohydrazide derivative provided by the present application as molecular probe, its structure is stable, synthesis method is simple, has the ability of responding to multiple substrates, and water-soluble, has wide application prospect.

Description

Technical Field

[0001] This invention relates to an organic small molecule probe, and more specifically, to a water-soluble carbazide derivative thereof, its preparation method, and a method for detecting ions or amino acids. Background Technology

[0002] It is well known that various bioactive substances exist in living systems, influencing metabolism and the processes of birth, aging, illness, and death. These include amino acids, enzymes, hypochlorous acid, hydrogen sulfide, and various anions and cations. The detection of these bioactive substances has become a research hotspot. Amino acids, as essential nutrients for the human body, play a crucial role in metabolic regulation and information transmission. Various anions and cations also play vital roles in the normal functioning of the body; for example, calcium... 2+ Cu 2+ Zn 2+ Cations such as AcO participate in biological processes such as bone development, synaptic transmission, metalloenzyme construction, and hematopoiesis; - HSO4 - Anions play a crucial role in regulating acid-base balance, lipid synthesis, drug metabolism, and protein structure stability in the human body. However, another class of ions, such as Hg... 2+ Cd 2+ These substances possess significant biotoxicity; even very low concentrations can cause substantial harm to the body and they can accumulate in the human body through the food chain. Therefore, the detection and quantification of these active substances, as well as timely and sensitive environmental monitoring of toxic ions, are of great importance in research fields such as food safety, environmental protection, and medical diagnosis.

[0003] In recent years, molecular probe detection methods, which use small organic molecules as probes to detect ions and small molecules, have attracted widespread attention due to their many advantages, such as high sensitivity, good selectivity, simple operation, low cost, real-time online monitoring, and applicability in living organisms.

[0004] Most reported molecular probes are "one-to-one" probes, meaning that a single probe can only selectively recognize one type of ion or molecule. Furthermore, the reported molecular probes have poor water solubility, making them unusable in completely aqueous solutions and failing to meet the detection needs of complex real-world samples. Therefore, developing efficient "one-to-many" multi-substrate detection probes that can be used in aqueous solutions is of significant application value for detecting complex real-world environmental samples. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a water-soluble carbazide derivative, its preparation method, and a method for detecting ions or amino acids. This invention introduces different pyridine groups onto the hydrazine group of carbazides, obtaining a class of pyridine-substituted carbazide derivatives. Compared to existing carbazide compounds, the recognition function of the pyridine-substituted carbazide derivatives provided by this invention is expanded and regulated, enabling their application in Cu... 2+ Hg 2+ Ca 2+ Cd 2+ Zn 2+ AcO - HSO4 - In addition, it can be used to identify and detect glutamic acid (Glu) / L-aspartic acid (Asp) and lysine (Lys) / arginine (Arg).

[0006] One of the objectives of this invention is to provide a water-soluble carbonyl hydrazine derivative.

[0007] The water-soluble carbazide derivative is L1 or L2;

[0008] The structural formula of L1 is: Named N',2-bis(3-pyridyl)carbonylhydrazine,

[0009] The structural formula of L2 is: It was named N,1-bis(2-pyridyl)carbonylhydrazide.

[0010] This invention uses carbonyl hydrazine as the parent compound and introduces pyridinium or pyridyl acyl groups onto the NH2 or NH group of the hydrazine group to construct a molecular probe with multiple recognition sites. The carbonyl and pyridinium groups in the molecule can bind metal ions, while the NH or NH2 groups can form hydrogen bonds with anions and amino acids. The molecule contains both relatively fixed acyl (urea) and pyridinium groups, as well as rotatable N–N, CN, and CC bonds, and its conformation can change depending on the binding of different recognition substrates, resulting in recognition selectivity. Aromatic heterocyclic pyridines expand the planar structure of the molecule, enhance its optical properties, and improve the probe's photoresponse capability.

[0011] The nitrogen-containing pyridinium group introduced onto the hydrazine group of carbonyl hydrazine can coordinate with metal ions and its structure is easily modified. Introducing different pyridinium groups into carbonyl hydrazine can adjust the acidity of NH, affecting its recognition ability for acidic amino acids; the introduced pyridinium N atom can also provide additional metal ion recognition sites and different ion coordination modes, improving the recognition ability for Cu. 2+ Hg 2+ Cd 2+ Ni 2+The selectivity for metal ions provides a structural basis for multi-substrate detection. Simultaneously, the planar conjugated structure of the introduced pyridine group improves the optical properties of carbazide, enhancing the sensitivity of optical signal detection. Furthermore, the carbazide derivatives obtained by introducing the pyridine group exhibit excellent water solubility, significantly increasing their practicality. Therefore, the pyridine-substituted carbazide derivatives provided by this invention represent a class of "one-to-many" molecular probes with excellent water solubility, showing promising applications in the detection of anions, cations, and amino acids.

[0012] The second objective of this invention is to provide a method for preparing the above-mentioned water-soluble carbazide derivatives.

[0013] The synthetic route for the water-soluble carbazide derivatives is shown below:

[0014]

[0015] in, R in when R in When the product is L1, the product is the compound represented by formula a. R in When the product is L2, the product is the compound shown in formula b.

[0016] The method for preparing the water-soluble carbazide derivative L1 includes: using 3-hydrazine-pyridine compounds and triphosgene as reactants, and using a base as an initiator, the reaction is carried out in solvent A under the protection of a protective gas; the 3-hydrazine-pyridine compounds are one or more of 3-hydrazylpyridine and 3-hydrazylpyridine hydrochloride.

[0017] In the preparation method of water-soluble carbazide derivative L1:

[0018] The molar ratio of the 3-hydrazine pyridine compound, the base, and triphosgene is 1-6:0.4-4:1, preferably 1-3:1-4:1. In some embodiments of the present invention, the molar ratio of 3-hydrazylpyridine hydrochloride, the base, and triphosgene is 3.1:3.9:1.

[0019] The base is an inorganic base, such as one or more of NaOH, NaHCO3, and KOH. In some embodiments of the present invention, NaOH is used as the base to improve the yield of L1.

[0020] Solvent A is a mixture of water and an organic solvent, preferably one or more of chloroform, dichloromethane, carbon tetrachloride, and benzene; for example, a mixture of water and chloroform, dichloromethane, carbon tetrachloride, or benzene. The volume ratio of water to organic solvent in the mixture can be 1-5:5-50. To improve the yield of L1, in some embodiments of the present invention, solvent A is a mixture of water and chloroform in a 1:1 ratio.

[0021] The protective gas is an inert gas or nitrogen. In some embodiments of the present invention, the protective gas used is argon.

[0022] The reaction temperature is 0-78°C, preferably 18-70°C. In some embodiments of the present invention, the reaction temperature is 25°C.

[0023] The preparation method of L1 may specifically include the following steps: dissolving a 3-hydrazine-pyridine compound and a base in solvent A to obtain an alkaline solution of the 3-hydrazine-pyridine compound; dissolving triphosgene in solvent A to obtain a triphosgene solution; mixing the alkaline solution of the 3-hydrazine-pyridine compound and the triphosgene solution and reacting to obtain a crude product; concentrating the crude product and then separating and purifying it to obtain L1. Preferably, the concentration refers to vacuum distillation, and the purification is performed using column chromatography / thin-layer chromatography and recrystallization. Specifically, after the reaction is completed, the reaction solution solvent A is removed under reduced pressure, and separation is performed using preparative thin-layer chromatography with dichloromethane / methanol (2 / 1, V / V) as the developing solvent. The second band under ultraviolet light (245 nm) is collected, and the red flaky crystals obtained are L1.

[0024] The preparation method of L2 includes: using 2-pyridinecarboxylhydrazide and triphosgene as reactants, and using a base as an initiator, the reaction is carried out in solvent B under the protection of a protective gas.

[0025] In the preparation method of water-soluble carbazide derivative L2:

[0026] The molar ratio of 2-pyridinecarboxylhydrazide, the base, and triphosgene is 1-6:0.4-4:1, preferably 1-3:1-4:1. In some embodiments of the present invention, the molar ratio of 2-pyridinecarboxylhydrazide, the base, and triphosgene is 1.2:1:1.

[0027] The base is an organic base, such as one or both of triethylamine and DBU. In some embodiments of the invention, triethylamine is used as the base to improve the yield of L2.

[0028] Solvent B is an organic solvent, preferably one or more of chloroform, dichloromethane, carbon tetrachloride, and benzene; for example, chloroform, dichloromethane, carbon tetrachloride, or benzene. In some embodiments of the present invention, solvent B is chloroform to improve the yield of L2.

[0029] The protective gas is an inert gas or nitrogen. In some embodiments of the present invention, the protective gas used is argon.

[0030] The reaction temperature is 0-78°C, preferably 18-70°C. In some embodiments of the present invention, the reaction temperature is 25°C.

[0031] The preparation method of L2 may specifically include the following steps: dissolving 2-pyridinecarboxylhydrazide and a base in solvent B to obtain an alkaline solution of 2-pyridinecarboxylhydrazide; dissolving triphosgene in solvent B to obtain a triphosgene solution; mixing the alkaline solution of 2-pyridinecarboxylhydrazide and the triphosgene solution and reacting to obtain a crude product; concentrating the crude product and then separating and purifying it to obtain L2; preferably, the concentration refers to vacuum distillation, and the purification is performed using column chromatography / thin-layer chromatography and recrystallization. Specifically, after the reaction is completed, the reaction solution solvent B is removed under reduced pressure, and separation is performed using preparative thin-layer chromatography with ethyl acetate / methanol (80 / 1, V / V) as the developing solvent. The first band under ultraviolet light (245 nm) is collected, and the pale yellow needle-like solid obtained is L2.

[0032] A third objective of this invention is to provide a method for detecting metal ions or amino acid acids using the aforementioned water-soluble carbazide derivatives L1 and L2 as detection probes.

[0033] The method for detecting metal ions or amino acid acids includes:

[0034] Using the water-soluble carbazide derivative L1 as a detection probe, Cu was selectively detected by visual colorimetry or ultraviolet light. 2+ or Hg 2+ Alternatively, using the water-soluble carbazide derivative L2 as a detection probe, Cu can be identified by visual colorimetry and fluorescence methods. 2+ Ca 2+ Zn 2+ Cd 2+ AcO - HSO4 - Lysine, arginine, glutamic acid, or L-aspartic acid. It is important to note that during detection and identification, both L1 and L2 are in solution form as detection probes, and the sample to be tested is also in solution form. Specifically, the solvent of the sample to be tested should be the same as the solvent of the corresponding L1 or L2, or the solvent of the sample to be tested should be the same as at least one of the solvents of the corresponding L1 or L2.

[0035] Specifically, the methods for detecting metal ions or amino acids mentioned above include any one or more of the following detection methods.

[0036] Using the water-soluble carbazide derivative L1 as a detection probe, the presence of Cu in the sample is identified by visual colorimetry.2+ or Hg 2+ Selective identification of Cu by visual colorimetry 2+ / Hg 2+ The method is as follows: (1) The L1 probe is in full contact with the sample to be tested to form a sample containing the probe and Cu. 2+ / Hg 2+ (1) Detection system of the compound obtained from the reaction; (2) Directly observe with the naked eye whether the color of the detection system changes from colorless to purple, in order to determine whether the sample to be tested contains Cu. 2+ / Hg 2+ For example, when the test sample causes the aqueous solution, CH3OH / H2O solution, or THF / H2O solution of the water-soluble carbazide derivative L1 to turn a visually recognizable purple color, the test sample contains Cu. 2+ For example, when the test sample causes the CH3CN / H2O solution or DMF / H2O solution of the water-soluble carbazide derivative L1 to turn a visually recognizable purple color, the test sample contains Hg. 2+ .

[0037] Using the water-soluble carbazide derivative L1 as a detection probe, the presence of Cu in the sample is identified by changes in the ultraviolet-visible absorption spectrum. 2+ or Hg 2+ Selective detection of Cu by changes in ultraviolet-visible absorption spectroscopy. 2+ / Hg 2+ The method is as follows: (1) The L1 probe is in full contact with the sample to be tested to form a sample containing the probe and Cu. 2+ / Hg 2+ (1) Detection system of the compound obtained from the reaction; (2) Measure the ultraviolet absorption spectrum of the system to determine the Cu content in the sample. 2+ / Hg 2+ The content. For example:

[0038] When the sample causes an increase in the intensity of the absorption peaks at 234 nm and 289 nm and a blue shift in the UV-Vis absorption spectra of the aqueous solution, CH3OH / H2O solution, or THF / H2O solution of the water-soluble carbazide derivative L1, and a new absorption peak appears at 522 nm, the sample contains Cu. 2+ ; For Cu 2+ The detection limit is 3.55 × 10⁻⁶. -6 M.

[0039] When the UV-Vis absorption spectra of the water-soluble carbazide derivative L1 in CH3CN / H2O or DMF / H2O solution show a decrease in the intensity of the absorption peaks at 235 nm and 290 nm, respectively, and a red shift to 240 nm and 308 nm, respectively, while a new absorption peak appears at 547 nm, the sample to be tested contains Hg. 2+ ; For Hg 2+ The detection limit was 4.74 × 10⁻⁶. -6 M.

[0040] Using the water-soluble carbazide derivative L2 as a detection probe, the presence of Cu in the sample is identified by visual colorimetry. 2+ For example, when the test sample causes the aqueous solution of the water-soluble carbazide derivative L2 to change to a visually perceptible pale yellow, the test sample contains Cu. 2+ .

[0041] Using the water-soluble carbazide derivative L2 as a detection probe, the presence of Cu in the sample is identified by changes in the ultraviolet-visible absorption spectrum. 2+ For example, when the sample causes a new absorption peak to appear at 221 nm and a decrease in the intensity of the absorption peak at 285 nm and a blue shift to 274 nm in the UV-Vis absorption spectrum of the aqueous solution of the water-soluble carbazide derivative L2, the sample contains Cu. 2+ ; For Cu 2+ The detection limit was 4.18 × 10⁻⁶. -6 M.

[0042] Using the water-soluble carbazide derivative L2 as a detection probe, the presence of Ca in the sample is identified by changes in fluorescence emission spectra. 2+ Zn 2+ Cd 2+ AcO - HSO4 - Amino acid A or amino acid B. Ca2+ can be selectively detected by changes in fluorescence emission spectroscopy. 2+ Cd 2+ Zn 2+ AcO - HSO4 - The method for adding glutamic acid (Glu), L-aspartic acid (Asp), lysine (Lys) or arginine (Arg) is as follows: (1) The L2 probe is in full contact with the sample to be tested to form a sample containing the probe and Ca 2+ Cd 2+ Zn 2 + AcO - HSO4 -(1) A detection system for compounds obtained by reacting glutamic acid (Glu), L-aspartic acid (Asp), lysine (Lys), or arginine (Arg); (2) Measuring the fluorescence emission spectrum of the system to determine the Ca content in the sample. 2+ Cd 2+ Zn 2+ AcO - HSO4 - The content of glutamic acid (Glu), L-aspartic acid (Asp), lysine (Lys), or arginine (Arg). The excitation wavelength of the fluorescence emission spectrum of the water-soluble carbazide derivative L2 probe is 330 nm. For example:

[0043] The water-soluble carbazide derivative L2 is used as a detection probe. Its CH3OH / H2O solution, when excited with 330 nm UV light, exhibits a weak fluorescence emission peak at 412 nm. When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 440 nm and the fluorescence intensity increases to 5.4 ± 0.5 times the original value, the sample contains Ca. 2+ ; for Ca 2+ The detection limit was 8.89 × 10⁻⁶. -6 M.

[0044] The water-soluble carbazide derivative L2 is used as a detection probe. Its CH3OH / H2O solution, when excited with 330 nm UV light, exhibits a weak fluorescence emission peak at 412 nm. When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 459 nm and the fluorescence intensity increases to 7.7 ± 0.5 times the original value, the sample contains Zn. 2+ ; For Zn 2+ The detection limit is 7.80 × 10⁻⁶. -6 M.

[0045] The water-soluble carbazide derivative L2 is used as a detection probe. Its CH3OH / H2O solution, when excited with 330 nm UV light, exhibits a weak fluorescence emission peak at 412 nm. When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 437 nm and the fluorescence intensity increases to 10.9 ± 0.5 times the original value, the sample contains Cd. 2+ ; For Cd 2+ The detection limit was 8.58 × 10⁻⁶. -6 M.

[0046] An acetonitrile solution of the water-soluble carbazide derivative L2, when excited with 330 nm UV light, exhibits a fluorescence emission peak at 423 nm. When the sample increases the emission peak intensity of the acetonitrile solution of the water-soluble carbazide derivative L2 by 1.7 ± 0.5 times, the sample contains AcO. - ; For AcO - The detection limit is 1.11 × 10⁻⁶. -6 M.

[0047] An acetonitrile solution of the water-soluble carbazide derivative L2 exhibits a fluorescence emission peak at 423 nm when excited by 330 nm UV light. When the sample to be tested reduces the emission peak of the acetonitrile solution of the water-soluble carbazide derivative L2 to 1 / 10-1 / 8 of its original value, the sample to be tested contains HSO4. - ; For HSO4 - The detection limit is 2.51 × 10⁻⁶. -6 M.

[0048] The CH3CN / H2O solution of the water-soluble carbazide derivative L2, when excited with 330 nm UV light, exhibits a fluorescence emission peak at 430 nm. When the sample increases the emission peak intensity of the CH3CN / H2O solution of the water-soluble carbazide derivative L2 by 2 ± 0.5 times, the sample contains lysine (Lys) and / or L-arginine (Arg); the detection limit for lysine is 2.75 × 10⁻⁶. -6 M; The detection limit for L-arginine is 5.15 × 10⁻⁶. -6 M.

[0049] The CH3CN / H2O solution of the water-soluble carbazide derivative L2, when excited with 330 nm UV light, exhibits a fluorescence emission peak at 430 nm. When the analyte quenches the fluorescence emission spectrum of the CH3CN / H2O solution of the water-soluble carbazide derivative L2, reducing the fluorescence intensity of the emission peak to 1 / 9-1 / 7 of its original value, the analyte contains glutamic acid; the detection limit for glutamic acid is 1.52 × 10⁻⁶. -5 M. When the sample to be tested causes fluorescence quenching in the CH3CN / H2O solution of the water-soluble carbazide derivative L2, reducing the fluorescence intensity of the emission peak to 1 / 27-1 / 25 of its original value, the sample to be tested contains L-aspartic acid; the detection limit for L-aspartic acid is 8.88 × 10⁻⁶. -6 M.

[0050] This invention detects Cu by visual colorimetry and ultraviolet light. 2+The solvent used can be water, CH3OH / H2O, or THF (tetrahydrofuran) / H2O; Hg is detected by visual colorimetry and ultraviolet light. 2+ The solvent used can be DMF (N,N-dimethylformamide) / H2O or CH3CN / H2O; Ca is detected by fluorescence methods. 2+ Cd 2+ Zn 2+ The solvent used can be CH3OH / H2O or water; AcO is detected by fluorescence methods. - HSO4 - The solvent used can be acetonitrile; the solvent used for detecting Glu / Asp / Lys / Arg by fluorescence methods can be CH3CN / H2O; the concentration of L1 or L2 probes can be 5.0 × 10⁻⁶. -5 mol / L.

[0051] Experiments have verified that Cu in the detection system 2+ / Hg 2+ When ions are present, they are at least not affected by the following ions: Na + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ Ca in the detection system 2+ Cd 2+ Zn 2+ When ions are present, they are at least not affected by the following ions: Na + Mg 2+ Ca 2+ Mn 2+ Co 2+ Zn 2+ 、Sr 2+ Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ AcO in the detection system - When ions are present, they are at least not affected by the following ions: Br - Cl -HSO4 - I - NO3 - H2PO4 - F - ClO4 - HSO4 in the detection system - When ions are present, they are at least not affected by the following ions: Br - Cl - I - NO3 - ClO4 - When detecting glutamic acid / L-aspartic acid / lysine / arginine, it shall not be affected by at least the following amino acids: glycine, alanine, serine, threonine, valine, leucine, tryptophan, tyrosine, histidine, L-proline, L-phenylalanine, D-cysteine, L-methionine, L-(+)-asparagine, and L-glutamine.

[0052] The detection performance of the probe molecules synthesized in this invention is evaluated using the following process:

[0053] Visual colorimetric evaluation: The prepared concentration is 5.0 × 10⁻⁶. -5 mol / L probe molecule solution and 2.5×10 -3 Different mol / L aqueous solutions of metal ions were used. A certain amount of probe molecule solution was mixed with one equivalent of the metal ion aqueous solution, and the color change of the solution was directly observed with the naked eye. The results showed that in H2O, CH3OH / H2O, and THF / H2O, Cu... 2+ It can change the color of probe L1 solution from colorless to purple; in DMF / H2O and CH3CN / H2O, Hg 2+ It can change the color of probe L1 solution from colorless to purple; in H2O, Cu 2+ The color of the L2 probe solution changed from colorless to yellow; while the other ions showed no significant change. This indicates that the L1 and L2 probe molecules can react with Cu in different solvent systems. 2+ or Hg 2+ Ions exhibit significant colorimetric selectivity.

[0054] Evaluation by UV-Vis absorption spectroscopy: The concentration was 5.0 × 10⁻⁶. -5 mol / L probe molecule solution and 2.5×10 -3 Aqueous solutions of different metal ions at mol / L were used. A certain amount of probe molecule solution was mixed with one equivalent of the aqueous solution of metal ions, and the UV-Vis absorption spectra of the probe molecules and their mixtures with different ions were measured. The results showed that Cu in H₂O, CH₃OH / H₂O, and THF / H₂O... 2+This causes a blue shift in the absorption peaks of probe L1 at 234 nm and 289 nm, and a new absorption peak appears near 522 nm; in DMF / H2O and CH3CN / H2O, Hg 2+ This causes a red shift in the absorption peaks of probe L1 at 235 nm and 290 nm, resulting in a new absorption peak at 547 nm; in H2O, the addition of Cu... 2+ Subsequently, L2 exhibited a new absorption peak at 221 nm, with the absorption peak intensity at 285 nm decreasing and blue-shifting to 274 nm (Δλ = -11 nm), and a weak absorption band appearing at 415 nm. The other ions did not show such significant changes. This indicates that the probe molecules L1 and L2 can target Cu in different solvent systems. 2+ or Hg 2+ Ions exhibit significant ultraviolet-based selective recognition.

[0055] Fluorescence emission spectroscopy evaluation: The concentration was 5.0 × 10⁻⁶. -5 mol / L probe molecule solution and 2.5×10 -3 A mol / L aqueous solution of different metal ions / anions / amino acids was prepared. A certain amount of probe molecule solution was mixed with 1 equivalent of ion / amino acid aqueous solution, and excited with 330 nm light. The fluorescence emission spectra of the probe molecule and its mixtures with different ions were measured in the range of 330–650 nm. The cation test (CH3OH / H2O) results showed that probe L2 had a weak fluorescence emission peak at 412 nm. When Ca was added... 2+ Subsequently, the L2 fluorescence emission peak red-shifted to 440 nm (Δλ = 28 nm), and the fluorescence intensity increased to approximately 5.4 times its original value; with the addition of Zn 2+ Subsequently, the L2 fluorescence emission peak red-shifted to 459 nm (Δλ = 45 nm), and the fluorescence intensity increased to approximately 7.7 times its original value; with the addition of Cd... 2+ Subsequently, the L2 fluorescence emission peak red-shifted to 437 nm (Δλ = 25 nm), and the fluorescence intensity increased to approximately 10.9 times its original value. Other tested metal ions did not cause significant changes. Anion testing (acetonitrile) results indicated that the addition of AcO... - Afterwards, the fluorescence emission peak intensity of L2 at 423 nm increased to approximately 1.7 times its original value; with the addition of HSO4 - When tested, the fluorescence intensity of L2 decreased to approximately 1 / 10 to 1 / 8 of its original value, while other tested anions did not cause significant changes. Amino acid assays (CH3CN / H2O) showed that lysine (Lys) / arginine (Arg) increased the fluorescence emission peak intensity of probe L2 at 430 nm by approximately two times, while glutamic acid (Glu) and L-aspartic acid (Asp) weakened the fluorescence of L2 to approximately 1 / 8 and 1 / 26 of its original value, respectively. Other tested amino acids did not cause significant changes. This indicates that the probe molecule L2 reacts with Ca in different solvents.2+ Zn 2+ Cd 2+ AcO - HSO4 - Lysine (Lys), arginine (Arg), glutamic acid (Glu), and L-aspartic acid (Asp) exhibit significant fluorescence recognition selectivity.

[0056] The beneficial effects of this invention are as follows:

[0057] (1) The water-soluble carbazide derivatives provided by this invention are molecular probes with stable structure, simple synthesis method, ability to respond to a variety of substrates, good water solubility, and broad application prospects.

[0058] (2) Probe L1 can achieve Cu detection by adjusting the detection solvent. 2+ or Hg 2+ Highly selective colorimetric / UV recognition detection with a detection limit up to 10. -6 M. In particular, L1 and L2 can achieve Cu in pure water. 2+ For single-eye colorimetric identification, the detection limit in the ultraviolet-visible spectrum can reach 3.55 × 10⁻⁶. -6 M and 4.18×10 -6 M.

[0059] (3) Probe L2 can serve as a multifunctional probe, enabling fluorescent recognition of cations, anions, and amino acids in various solvents. For Ca... 2+ Zn 2+ Cd 2+ Fluorescent recognition can be performed in water; for AcO - HSO4 - Differential identification can be achieved through different signal modes (fluorescence enhancement and fluorescence quenching); in aqueous solvents, different fluorescence responses can also be achieved for small molecule amino acids lysine (Lys), arginine (Arg), glutamic acid (Glu), and L-aspartic acid (Asp). The detection limits for both anions and cations, as well as amino acids, can reach 10. -6 M.

[0060] In this invention, "***nm" refers to "***±5nm". Attached Figure Description

[0061] Figure 1 The L1 probe prepared for Example 1 of this invention reacts with Cu in water. 2+ Color change diagram before and after application;

[0062] Figure 2The UV-Vis absorption spectra of the L1 probe prepared in Example 1 of this invention after interacting with different metal ions in water; where the horizontal axis represents the absorption wavelength and the vertical axis represents the absorbance.

[0063] Figure 3 The L1 probe prepared for Example 1 of this invention was used to test Cu in an aqueous solution. 2+ The ultraviolet titration graph; where the horizontal axis is the absorption wavelength and the vertical axis is the absorbance;

[0064] Figure 4 The L1 probe prepared in Example 1 of this invention was reacted with Hg in CH3CN / H2O. 2+ Color change diagram before and after application;

[0065] Figure 5 The UV-Vis absorption spectra of the L1 probe prepared in Example 1 of this invention after interacting with different metal ions in CH3CN / H2O; where the horizontal axis is the absorption wavelength and the vertical axis is the absorbance.

[0066] Figure 6 The L1 probe prepared in Example 1 of this invention was used to target Hg in CH3CN / H2O. 2+ The ultraviolet titration graph; where the horizontal axis is the absorption wavelength and the vertical axis is the absorbance;

[0067] Figure 7 The L2 probe prepared for Example 2 of this invention reacts with Cu in water. 2+ Color change diagram before and after application;

[0068] Figure 8 The UV-Vis absorption spectra of the L2 probe prepared in Example 2 of this invention after interacting with different metal ions in water; where the horizontal axis represents the absorption wavelength and the vertical axis represents the absorbance.

[0069] Figure 9 The fluorescence emission spectra of the L2 probe prepared in Example 2 of the present invention after reacting with different metal ions in CH3OH / H2O are shown, where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity.

[0070] Figure 10 The L2 probe prepared in Example 2 of this invention was used to target Ca in CH3OH / H2O. 2+ The fluorescence titration graph; where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity;

[0071] Figure 11 The L2 probe prepared for Example 2 of this invention was used to target Zn in CH3OH / H2O. 2+ The fluorescence titration graph; where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity;

[0072] Figure 12 The L2 probe prepared in Example 2 of this invention was used to target Cd in CH3OH / H2O. 2+ The fluorescence titration graph; where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity;

[0073] Figure 13 The fluorescence emission spectra of the L2 probe prepared in Example 2 of the present invention after reacting with different anions in acetonitrile are shown, where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity.

[0074] Figure 14 The L2 probe prepared for Example 2 of this invention was used to react with AcO in acetonitrile. - The fluorescence titration graph; where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity;

[0075] Figure 15 The L2 probe prepared for Example 2 of this invention reacts with HSO4 in acetonitrile. - The fluorescence titration graph; where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity;

[0076] Figure 16 The fluorescence emission spectrum of the L2 probe prepared in Example 2 of this invention after reacting with amino acids in CH3CN / H2O is shown, where the horizontal axis is the emission wavelength and the vertical axis is the fluorescence intensity.

[0077] Figure 17 The image shows the fluorescence titration of the L2 probe prepared in Example 2 of this invention on lysine (Lys) in CH3CN / H2O; where the horizontal axis represents the emission wavelength and the vertical axis represents the fluorescence intensity.

[0078] Figure 18 The image shows the fluorescence titration of the L2 probe prepared in Example 2 of this invention with arginine (Arg) in CH3CN / H2O; where the horizontal axis represents the emission wavelength and the vertical axis represents the fluorescence intensity.

[0079] Figure 19 The image shows the fluorescence titration of the L2 probe prepared in Example 2 of this invention on glutamate (Glu) in CH3CN / H2O; where the horizontal axis represents the emission wavelength and the vertical axis represents the fluorescence intensity.

[0080] Figure 20 The image shows the fluorescence titration of L-aspartic acid (Asp) with the L2 probe prepared in Example 2 of this invention in CH3CN / H2O; where the horizontal axis represents the emission wavelength and the vertical axis represents the fluorescence intensity.

[0081] Figure 21 The L2 probe prepared for Example 2 of this invention was used to test Cu in water. 2+ The ultraviolet titration graph; where the horizontal axis represents the absorption wavelength and the vertical axis represents the absorbance. Detailed Implementation

[0082] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0083] Unless otherwise specified, all materials and reagents used in the following examples are commercially available products.

[0084] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0085] Example 1

[0086] Synthesis of N',2-bis(3-pyridyl)carbonylhydrazine (L1)

[0087] The synthesis route for L1 is as follows:

[0088]

[0089] Under argon protection, 50 mg (0.34 mmol) of 3-hydrazinopyridine hydrochloride, 17 mg (0.43 mmol) of NaOH, and 5 mL of ultrapure water were dissolved in a 50 mL three-necked flask to obtain an alkaline solution of 3-hydrazinopyridine hydrochloride. 33 mg (0.11 mmol) of triphosgene was dissolved in 5 mL of chloroform solution to obtain a chloroform solution of triphosgene. The chloroform solution of triphosgene was added to the alkaline solution of 3-hydrazinopyridine hydrochloride, and the reaction was carried out at 25 °C. The reaction progress was monitored by thin-layer chromatography. After the reaction was complete, the solvent in the reaction solution was removed under reduced pressure, and the mixture was separated by preparative thin-layer chromatography using dichloromethane / methanol (2 / 1, V / V) as the developing solvent. The second band under a UV lamp (245 nm) was collected, yielding 29 mg of red flaky crystals, with a yield of 70%. Mp 102–103 °C. 1 H NMR(500MHz,DMSO-d6)δ8.57(2H,s,NHCO),8.11–8.04(2H,m,pyridyl),7.97–7.90(2H,m,py ridyl),7.90–7.81(2H,m,NH),7.18(2H,t,J=8.2Hz,pyridyl),7.09–7.00(2H,m,pyridyl). 13C NMR(125MHz,DMSO-d6)δ159.45(CONH),146.13,139.79,135.20,123.77,118.67(pyridyl).MS(EI):m / z calculated for C 11 H 12 N6O[M+H] + :245.25,found 245.05.

[0090] Example 2

[0091] Synthesis of N,1-bis(2-pyridyl)carbonylhydrazide (L2)

[0092] The synthesis route for L2 is as follows:

[0093]

[0094] Under argon protection, 50 mg (0.36 mmol) of 2-pyridinecarboxylhydrazide, 61 μL (0.44 mmol) of triethylamine, and 15 mL of chloroform were dissolved in a 50 mL three-necked flask to obtain an alkaline solution of 2-pyridinecarboxylhydrazide. 108 mg (0.36 mmol) of triphosgene was dissolved in 5 mL of chloroform to obtain a chloroform solution of triphosgene. The chloroform solution of triphosgene was added to the alkaline solution of 2-pyridinecarboxylhydrazide, and the reaction was carried out at 25 °C. The reaction progress was monitored by thin-layer chromatography. After the reaction was complete, the solvent in the reaction solution was removed under reduced pressure, and the mixture was separated by preparative thin-layer chromatography using ethyl acetate / methanol (80 / 1, V / V) as the developing solvent. The first band under UV light (245 nm) was collected, yielding 44 mg of a pale yellow needle-like solid, with a yield of 80%. Mp 184-185 °C. 1 H NMR(500MHz,DMSO-d6)δ8.66(2H,d,J=5.2Hz,pyridyl),7.97–7.91(2H,m,pyridyl),7.90–7.84(2H,m,pyridyl),7.53–7.47(2H,m,pyridyl),6.07(4H,s,NH2). 13 C NMR(125MHz,DMSO-d6)δ157.77,153.78(CON),150.35,144.22,137.91,125.60,121.39(pyridyl).MS(EI):m / zcalced for C 13 H 12 N6O3[M+H] + :301.1044,found301.1029.

[0095] Example 3

[0096] The effect of L1 prepared in Example 1 on various ions in the ultraviolet detection method

[0097] Prepare 1×10 in 100mL volumetric flasks. -4 Prepare 2.5 × 10⁻⁶ mol / L aqueous solutions of L⁻¹ in 25 mL volumetric flasks. -3 Cu mol / L 2+ Na + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Aqueous solutions of metal ions.

[0098] Take 1 mL of 1×10 -4 Add 1 mL of deionized water to an aqueous solution of L1 (mol / L) to obtain the L1 probe solution; For example... Figure 2 As shown, the L1 probe solution is colorless. 40 μL of each of the above-mentioned aqueous solutions of metal ions were added to the L1 probe solution and mixed thoroughly. The color change of the L1 probe solution was observed under sunlight, and its ultraviolet-visible absorption spectrum was measured.

[0099] like Figure 1 As shown, Cu was added 2+ Subsequently, the color of the L1 probe solution changed from colorless to purple. For example... Figure 2 As shown, Cu was added 2+ Subsequently, the UV-Vis spectrum of the L1 probe showed increased absorption peak intensities at 234 nm and 289 nm with a blue shift (Δλ = -1 nm, -4 nm), while a new absorption peak appeared near 522 nm. Its selectivity was demonstrated by the addition of Na... + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Subsequently, no significant changes were observed in the color of the L1 probe solution or the UV-Vis spectrum of the L1 probe. This detection result is also applicable to L1 probe molecules in CH3OH / H2O (7-3 / 3-7, V / V) and THF / H2O (7-3 / 3-7, V / V) solution systems.

[0100] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 After adding 1 mL of deionized water to an aqueous solution of Cu mol / L L1, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the above Cu were added respectively. 2+ The ion-water solution was mixed, and its UV-Vis absorption spectrum was measured. The results were obtained using UV technology. Figure 3 The UV titration diagram shown indicates the reaction between the L1 probe molecule and Cu. 2+ The complexation constant is 2.19 × 10⁻⁶. 3 M -1 The detection limit was calculated to be 3.55 × 10⁻⁶ using the Benesi-Hiderbrand (B-H equation) method. - 6 M. The same method was used to determine the effect of L1 probe CH3OH / H2O solution or THF / H2O solution on Cu. 2+ The detection limits were 2.5 × 10⁻⁶. -5 M, 1.06×10 -4 M.

[0101] Example 4

[0102] The effect of L1 prepared in Example 1 on various ions in the ultraviolet detection method

[0103] Prepare 1×10 in a 100mL volumetric flask. -4 Prepare a 2.5 × 10⁻⁶ mol / L acetonitrile solution in a 25 mL volumetric flask. -3 Cu mol / L 2+ Na + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn2+ 、Sr 2+ Ag + Cd 2+ Ba 2 + Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Aqueous solutions of metal ions.

[0104] Take 1 mL of 1×10 -4 Add 1 mL of deionized water to a mol / L acetonitrile solution of L1 to obtain a CH3CN / H2O solution for the L1 probe; For example... Figure 4 As shown, the L1 probe CH3CN / H2O solution was colorless. 40 μL of each of the above-mentioned aqueous solutions of metal ions were added to the L1 probe CH3CN / H2O solution and mixed thoroughly. The color change of the L1 probe CH3CN / H2O solution was observed under sunlight, and its UV-Vis absorption spectrum was measured.

[0105] like Figure 4 As shown, add Hg 2+ Subsequently, the color of the L1 probe CH3CN / H2O solution changed from colorless to purple. For example... Figure 5 As shown, add Hg 2+ Subsequently, the UV-Vis spectrum of the L1 probe showed a decrease in absorption peak intensity at 235 nm and 290 nm, which then red-shifted to 240 nm and 308 nm, respectively, while a new absorption peak appeared near 547 nm. Its selectivity was demonstrated by the addition of Na... + Mg 2+ Al 3 + Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Cu 2+ Subsequently, the color of the L1 probe CH3CN / H2O solution and the UV-Vis spectrum of the L1 probe did not show any significant changes.

[0106] This detection result is also applicable to the DMF / H2O solution system of L1 probe molecules.

[0107] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 After adding 1 mL of deionized water to a mol / L L1 acetonitrile solution, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the above-mentioned Hg were added respectively. 2+ The ion-water solution was mixed, and its UV-Vis absorption spectrum was measured. The results were obtained using UV technology. Figure 6 The UV titration diagram shown indicates the reaction between the L1 probe molecule and Hg. 2+ The complexation constant is 1.26 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 4.74 × 10⁻⁶ using the Benesi-Hiderbrand (B-H equation) method. - 6 M. The DMF / H2O solution of L1 was used to determine the effect of Hg on Hg using the same method. 2+ The detection limit was 4.95 × 10⁻⁶. -6 M.

[0108] Example 5

[0109] The effect of L2 prepared in Example 2 on various ions in the ultraviolet detection method

[0110] Prepare 1×10 in 100mL volumetric flasks. -4 Prepare 2.5 × 10⁻⁶ mol / L L⁻¹ aqueous solutions in 25 mL volumetric flasks. -3 Cu mol / L 2+ Na + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Aqueous solutions of metal ions.

[0111] Take 1 mL of 1×10 -4 Add 1 mL of deionized water to an aqueous solution of L2 (mol / L) to obtain the L2 probe solution; For example... Figure 7As shown, the L2 probe solution is colorless. 40 μL of each of the above-mentioned aqueous solutions of metal ions were added to the L2 probe solution and mixed thoroughly. The color change of the L2 probe solution was observed under sunlight, and its ultraviolet-visible absorption spectrum was measured.

[0112] like Figure 7 As shown, Cu was added 2+ Subsequently, the color of the L2 probe solution changed from colorless to pale yellow. For example... Figure 8 As shown, Cu was added 2+ Subsequently, the L2 probe's UV-Vis spectrum showed a new absorption peak at 221 nm, a decreased absorption peak intensity at 285 nm that blue-shifted to 274 nm (Δλ = -11 nm), and a weak absorption band at 365 nm. Its selectivity was demonstrated by the addition of Na... + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Afterwards, the color of the L2 probe solution and the UV-Vis spectrum of the L2 probe did not change significantly.

[0113] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 After adding 1 mL of deionized water to an aqueous solution of Cu mol / L L2, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the above-mentioned Cu 2+ The ion-water solution was mixed, and its UV-Vis absorption spectrum was measured. The results were obtained using UV technology. Figure 21 The UV titration diagram shown indicates the reaction between the L2 probe molecule and Cu. 2+ The complexation constant is 7.40 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 4.18 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). - 6 M.

[0114] Example 6

[0115] The effect of L2 prepared in Example 2 on metal ions in a fluorescence detection method

[0116] Prepare 1×10 in 100mL volumetric flasks. -4 A methanol solution of mol / L L⁻¹ was prepared in a 25 mL volumetric flask to achieve a concentration of 2.5 × 10⁻⁶ mol / L. -3 Cu mol / L 2+ Na + Mg 2+ Al 3+ Ca 2+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ 、Sr 2+ Ag + Cd 2+ Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Hg 2+ Aqueous solutions of metal ions.

[0117] Take 1 mL of 1×10 -4 Add 1 mL of deionized water to a methanol solution of L2 (mol / L) to obtain an L2 probe CH3OH / H2O solution. Add 40 μL of each of the above-mentioned aqueous solutions of metal ions to the L2 probe CH3OH / H2O solution and mix thoroughly. Observe the color change of the L2 probe CH3OH / H2O solution under sunlight and test its fluorescence emission spectrum.

[0118] like Figure 9 As shown, the L2 probe molecule is only sensitive to Ca 2+ Zn 2+ Cd 2+ The ions produce changes in fluorescence emission spectra. The L2 probe CH3OH / H2O solution, when excited with 330 nm light, shows a weak fluorescence emission peak at 412 nm; the addition of Ca... 2+ Subsequently, the fluorescence emission peak of the L2 probe red-shifted to 440 nm (Δλ = 28 nm), and the fluorescence intensity increased to 5.4 times its original value; with the addition of Zn 2+ Subsequently, the fluorescence emission peak of the L2 probe red-shifted to 459 nm (Δλ = 45 nm), and the fluorescence intensity increased to 7.7 times its original value; with the addition of Cd... 2+ Subsequently, the fluorescence emission peak of the L2 probe red-shifted to 437 nm (Δλ = 25 nm), and the fluorescence intensity increased to 10.9 times its original value. Its selectivity is demonstrated by the addition of Na... + Mg 2+ Al 3+ Cr 3+ Mn 2+ Fe 3+ Co 2+ Ni 2+ Hg 2+ 、Sr 2+ Ag + Ba 2+ Pb 2+ La 3+ 、Nd 3+ and Cu 2+ Afterwards, the fluorescence properties of the L2 probe did not change significantly.

[0119] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 After adding 1 mL of deionized water to a methanol solution of mol / L L2, the solution was then reacted with 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the aforementioned Ca2+ solution. 2+ / Zn 2+ / Cd 2+ The ion-water solution was mixed, and its fluorescence emission spectrum was measured. The fluorescence spectrum was obtained using fluorescence techniques. Figure 10 The fluorescence titration diagram shown indicates the reaction between the L2 probe molecule and Ca. 2+ The complexation constant is 0.36 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 8.89 × 10⁻⁶ using the Benesi-Hiderbrand (B-H equation) method. -6 M. Obtained through fluorescence technology, such as Figure 11 The fluorescence titration diagram shown indicates the interaction between the L2 probe molecule and Zn. 2+ The complexation constant is 4.13 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 7.80 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -6 M. Obtained through fluorescence technology, such as Figure 12 The fluorescence titration diagram shown indicates the reaction between the L2 probe molecule and Cd. 2+ The complexation constant is 1.85 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 8.58 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -6 M.

[0120] Example 7

[0121] The effect of L2 prepared in Example 2 on anions in a fluorescence detection method

[0122] Prepare 1×10 in 100mL volumetric flasks. -4 Prepare 2.5 × 10⁻⁶ mol / L L⁻¹ acetonitrile solutions in 25 mL volumetric flasks. -3 mol / L AcO - HSO4 - ,Br - Cl - I - NO3 - H2PO4 - F - ClO4 - Anionic acetonitrile solution.

[0123] Take 1 mL of 1×10 -4 Add 1 mL of acetonitrile to a mol / L L2 acetonitrile solution to obtain an L2 probe acetonitrile solution. Add 40 μL of each of the above anion acetonitrile solutions to the L2 probe acetonitrile solution respectively, mix thoroughly, and then measure their fluorescence emission spectra.

[0124] like Figure 13 As shown, the L2 probe molecule is only effective against AcO - HSO4 - The ions produce a change in the fluorescence emission spectrum. The L2 probe acetonitrile solution, when excited with 330 nm light, shows a fluorescence emission peak at 423 nm; the addition of AcO... - Afterwards, the fluorescence emission peak intensity of the L2 probe at 423 nm increased to 1.7 times its original value; with the addition of HSO4 - At that time, the fluorescence intensity of the L2 probe decreased to 1 / 9 of its original value. Its selectivity was as follows: upon addition of Br... - Cl - I - NO3 - H2PO4 - F - ClO4 - Afterwards, the fluorescence properties of the L2 probe did not change significantly.

[0125] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 After adding 1 mL of acetonitrile to a mol / L L2 acetonitrile solution, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the above AcO2 solution were added respectively. - / HSO4 - The fluorescence emission spectrum of a mixture of ionic acetonitrile solutions was measured. Fluorescence techniques were used to obtain... Figure 14 The fluorescence titration diagram shown indicates the reaction between the L2 probe molecule and AcO. - The complexation constant is 1.01 × 10⁻⁶. 5 M-1 The detection limit was calculated to be 1.11 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). - 6 M. Obtained through fluorescence technology, such as Figure 15 The fluorescence titration diagram shown indicates the reaction of L2 probe molecules with HSO4. - The complexation constant is 2.44 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 2.51 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -6 M.

[0126] Example 8

[0127] The effect of L2 prepared in Example 2 on amino acids in a fluorescence detection method

[0128] Prepare 1×10 in 100mL volumetric flasks. -4 A solution of acetonitrile in L2 at a concentration of mol / L was prepared in a 25 mL volumetric flask to a concentration of 2.5 × 10⁻⁶ mol / L. -3 Aqueous solutions of lysine (Lys), L-arginine (Arg), glutamic acid (Glu), L-aspartic acid (Asp), glycine, alanine, serine, threonine, valine, leucine, tryptophan, tyrosine, histidine, L-proline, L-phenylalanine, D-cysteine, L-methionine, L-(+)-asparagine and L-glutamine.

[0129] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 A solution of 1 mol / L L2 acetonitrile was added to 400 μL of acetonitrile and 600 μL of deionized water, and then mixed with 40 μL of the above-mentioned amino acid aqueous solutions, and the fluorescence emission spectra were measured.

[0130] like Figure 16 As shown, the L2 probe in CH3CN / H2O solution exhibits a fluorescence emission peak at 430 nm under UV excitation at 330 nm. The fluorescence intensity of the emission peak doubles upon the addition of lysine (Lys) and / or L-arginine (Arg). Fluorescence quenching occurs upon the addition of Glu or / Asp, with the fluorescence intensity decreasing to 1 / 8 and 1 / 26 of the original values, respectively. Its selectivity is demonstrated by the fact that the fluorescence spectrum of the L2 probe does not change significantly upon the addition of glycine, alanine, serine, threonine, valine, leucine, tryptophan, tyrosine, histidine, L-proline, L-phenylalanine, D-cysteine, L-methionine, L-(+)-asparaginic acid, and L-glutamine.

[0131] Use a pipette to take 1 mL of 1×10⁻⁶ fluid from the volumetric flask. -4 A solution of acetonitrile in L2 at a concentration of mol / L was mixed with 400 μL of acetonitrile and 600 μL of deionized water, and then further mixed with 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, and 40 μL of the aforementioned amino acid aqueous solution, respectively. The fluorescence emission spectra were then measured. The fluorescence spectra were obtained using fluorescence techniques. Figure 17 The fluorescence titration diagram shown indicates that the complexation constant between the L2 probe molecule and lysine (Lys) is 4.62 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 2.75 × 10⁻⁶ using the Benesi-Hiderbrand (B-H equation) method. -6 M. Obtained through fluorescence technology, such as Figure 18 The fluorescence titration diagram shown indicates that the complexation constant between the L2 probe molecule and L-arginine (Arg) is 2.46 × 10⁻⁶. 4 M -1 The detection limit was calculated to be 5.15 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -6 M. Obtained through fluorescence technology, such as Figure 19 The fluorescence titration diagram shown indicates that the complexation constant between the L2 probe molecule and glutamate (Glu) is 3.01 × 10⁻⁶. 3 M -1 The detection limit was calculated to be 1.52 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -5 M. Obtained through fluorescence technology, such as Figure 20 The fluorescence titration diagram shown indicates that the complexation constant between the L2 probe molecule and L-aspartic acid (Asp) is 5.36 × 10⁻⁶. 3 M -1 The detection limit was calculated to be 8.88 × 10⁻⁶ using the Benesi-Hiderbrand equation (B-H equation). -6 M.

Claims

1. A water-soluble carbazide derivative, characterized in that, The water-soluble carbazide derivative is L1 or L2; The structural formula of L1 is: The structural formula of L2 is .

2. A method for preparing the water-soluble carbazide derivative L1 as described in claim 1, characterized in that, The reaction is carried out using 3-hydrazine-pyridine compounds and triphosgene as reactants, with a base as an initiator, in solvent A under the protection of a protective gas; the 3-hydrazine-pyridine compounds are one or both of 3-hydrazylpyridine and 3-hydrazylpyridine hydrochloride.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the 3-hydrazine pyridine compound, the base, and triphosgene is 1-6:0.4-4:1; The alkali is an inorganic alkali; Solvent A is a mixture of water and organic solvent; The protective gas is an inert gas or nitrogen; The reaction temperature is 0-78℃.

4. The preparation method according to claim 3, characterized in that, The molar ratio of the 3-hydrazine pyridine compound, the base, and triphosgene is 1-3:1-4:1; The alkali is one or more of NaOH, NaHCO3 and KOH; The organic solvent is one or more of chloroform, dichloromethane, carbon tetrachloride, and benzene; The reaction temperature is 18~70℃.

5. The preparation method according to claim 2, characterized in that, Includes the following steps: A 3-hydrazine-pyridine compound and a base are dissolved in solvent A to obtain an alkaline solution of the 3-hydrazine-pyridine compound. Triphosgene is dissolved in solvent A to obtain a triphosgene solution. The alkaline solution of the 3-hydrazine-pyridine compound and the triphosgene solution are mixed and reacted to obtain a crude product. The crude product was concentrated and then separated and purified to obtain L1.

6. A method for preparing the water-soluble carbazide derivative L2 as described in claim 1, characterized in that, The reaction was carried out in solvent B under the protection of a protective gas, using 2-pyridinecarboxylhydrazine and triphosgene as reactants and a base as an initiator.

7. The preparation method according to claim 6, characterized in that, The molar ratio of 2-pyridinecarboxylhydrazide, base, and triphosgene is 1-6:0.4-4:1; The alkali is an organic alkali; Solvent B is an organic solvent; The protective gas is an inert gas or nitrogen; The reaction temperature is 0-78℃.

8. The preparation method according to claim 7, characterized in that, The molar ratio of 2-pyridinecarboxylhydrazide, base and triphosgene is 1-3:1-4:1; The base is one or both of triethylamine and DBU; Solvent B is one or more of chloroform, dichloromethane, carbon tetrachloride, and benzene; The reaction temperature is 18~70℃.

9. The preparation method according to claim 6, characterized in that, Includes the following steps: 2-Pyridinecarboxylhydrazide and a base were dissolved in solvent B to obtain an alkaline solution of 2-pyridinecarboxylhydrazide; triphosgene was dissolved in solvent B to obtain a triphosgene solution; the alkaline solution of 2-pyridinecarboxylhydrazide and the triphosgene solution were mixed and reacted to obtain a crude product; the crude product was concentrated and then separated and purified to obtain L2.

10. A method for non-disease diagnosis or treatment using the water-soluble carbazide derivative L1 of claim 1 for detecting ions, characterized in that, The method includes: The presence of Cu in the sample is identified by visual colorimetry. 2+ or Hg 2+ When the test sample causes the aqueous solution, CH3OH / H2O solution, or THF / H2O solution of the water-soluble carbazide derivative L1 to turn a visually recognizable purple color, the test sample contains Cu. 2+ ; The presence of Cu in the sample is identified by visual colorimetry. 2+ or Hg 2+ When the test sample causes the CH3CN / H2O solution or DMF / H2O solution of the water-soluble carbazide derivative L1 to turn a visually recognizable purple color, the test sample contains Hg. 2+ ; The presence of Cu in a sample can be identified by analyzing changes in its ultraviolet-visible absorption spectrum. 2+ or Hg 2+ When the sample causes an increase in the intensity of the absorption peaks at 234 nm and 289 nm and a blue shift in the UV-Vis absorption spectrum of the aqueous solution, CH3OH / H2O solution, or THF / H2O solution of the water-soluble carbazide derivative L1, and a new absorption peak appears at 522 nm, the sample contains Cu. 2+ ; The presence of Cu in a sample can be identified by analyzing changes in its ultraviolet-visible absorption spectrum. 2+ or Hg 2+ When the sample causes a decrease in the intensity of the absorption peaks at 235 nm and 290 nm in the UV-Vis absorption spectrum of the water-soluble carbazide derivative L1 in CH3CN / H2O or DMF / H2O solution, and a red shift to 240 nm and 308 nm respectively, while a new absorption peak appears at 547 nm, the sample contains Hg. 2+ .

11. The method as described in claim 10, characterized in that, The aqueous solution, CH3OH / H2O solution, or THF / H2O solution of the water-soluble carbazide derivative L1 are effective against Cu. 2+ The detection limits were 3.55 × 10⁻⁶. -6 M, 2.5×10 -6 M, 1.06×10 -4 M; The DMF / H2O or CH3CN / H2O solution of the water-soluble pyridyl hydrazine derivative L1 is effective against Hg. 2+ The detection limits were 4.95 × 10⁻⁶. -6 M, 4.74×10 -6 M.

12. The method as described in claim 10, characterized in that, The sample to be tested is dissolved in a solvent; the solvent used to dissolve the sample to be tested is at least one of the same solvents used to detect the water-soluble carbazide derivative L1 of the sample to be tested.

13. A method for non-disease diagnosis or treatment using the water-soluble carbazide derivative L2 of claim 1 for ion detection, characterized in that, The method includes: The presence of Cu in the sample is identified by visual colorimetry. 2+ When the test sample causes the aqueous solution of the water-soluble carbazide derivative L2 to change to a visually perceptible pale yellow, the test sample contains Cu. 2+ ; The presence of Cu in a sample can be identified by analyzing changes in its ultraviolet-visible absorption spectrum. 2+ When the sample causes a new absorption peak to appear at 221 nm and a decrease in the intensity of the absorption peak at 285 nm, followed by a blue shift to 274 nm in the UV-Vis absorption spectrum of the aqueous solution of the water-soluble carbazide derivative L2, the sample contains Cu. 2+ ; The presence of Ca in a sample can be identified by changes in fluorescence emission spectra. 2+ When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 440 nm and the fluorescence intensity to increase to 5.4 ± 0.5 times the original value, the sample contains Ca. 2+ ; The presence of Zn in a sample can be identified by changes in fluorescence emission spectra. 2+ When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 459 nm and the fluorescence intensity increases to 7.7 ± 0.5 times the original value, the sample contains Zn. 2+ ; The presence of Cd in a sample can be identified by changes in fluorescence emission spectra. 2+ When the sample causes a red shift of the emission peak of the CH3OH / H2O solution of the water-soluble carbazide derivative L2 to 437 nm and the fluorescence intensity increases to 10.9 ± 0.5 times the original value, the sample contains Cd. 2+ ; The presence of AcO in a sample can be identified by changes in fluorescence emission spectra. - When the sample increases the emission peak intensity of the acetonitrile solution of the water-soluble carbazide derivative L2 by 1.7 ± 0.5 times, the sample contains AcO. - ; The presence of HSO4 in a sample can be identified by changes in fluorescence emission spectra. - When the sample to be tested reduces the emission peak intensity of the acetonitrile solution of the water-soluble carbazide derivative L2 to 1 / 10-1 / 8 of its original value, the sample to be tested contains HSO4. - .

14. The method as described in claim 13, characterized in that, The aqueous solution of the water-soluble carbazide derivative L2 has a positive effect on Cu. 2+ The detection limit was 4.18 × 10⁻⁶. -6 M; The CH3OH / H2O solution of the water-soluble carbazide derivative L2 affects Ca 2+ The detection limit was 8.89 × 10⁻⁶. -6 M; The CH3OH / H2O solution of the water-soluble carbazide derivative L2 has a positive effect on Zn. 2+ The detection limit is 7.80 × 10⁻⁶. -6 M; The CH3OH / H2O solution of the water-soluble carbazide derivative L2 has a positive effect on Cd. 2+ The detection limit was 8.58 × 10⁻⁶. -6 M; The acetonitrile solution of the water-soluble carbazide derivative L2 has a positive effect on AcO. - The detection limit is 1.11 × 10⁻⁶. -6 M; The acetonitrile solution of the water-soluble carbazide derivative L2 for HSO4 - The detection limit is 2.51 × 10⁻⁶. -6 M.

15. The method as described in claim 13, characterized in that, The sample to be tested is dissolved in a solvent; the solvent used to dissolve the sample to be tested is at least one of the same solvents used to detect the water-soluble carbazide derivative L2 of the sample to be tested.

16. The method as described in claim 13, characterized in that, The excitation wavelength of the fluorescence emission spectrum of the water-soluble carbazide derivative L2 probe is 330 nm.

17. A method for non-disease diagnosis or treatment using the water-soluble carbazide derivative L2 as described in claim 1, characterized in that, The method includes: The presence of amino acids in a sample can be identified by changes in fluorescence emission spectra. When the sample to be tested increases the emission peak intensity of the CH3CN / H2O solution of the water-soluble carbazide derivative L2 by 2 ± 0.5 times, the sample to be tested contains lysine or L-arginine. When the sample to be tested can quench the fluorescence emission spectrum of the CH3CN / H2O solution of the water-soluble carbazide derivative L2, and reduce the fluorescence intensity of the emission peak to 1 / 9-1 / 7 of the original, the sample to be tested contains glutamic acid. When the sample to be tested can quench the fluorescence emission spectrum of the CH3CN / H2O solution of the water-soluble carbazide derivative L2, reducing the fluorescence intensity of the emission peak to 1 / 27-1 / 25 of the original, the sample to be tested contains L-aspartic acid.

18. The method as described in claim 17, characterized in that, The detection limit for lysine in the CH3CN / H2O solution of the water-soluble carbazide derivative L2 was 2.75 × 10⁻⁶. -6 M; The detection limit for L-arginine in the CH3CN / H2O solution of the water-soluble carbazide derivative L2 was 5.15 × 10⁻⁶. -6 M; The detection limit for glutamic acid in the CH3CN / H2O solution of the water-soluble carbazide derivative L2 was 1.52 × 10⁻⁶. -5 M; The detection limit for L-aspartic acid in the CH3CN / H2O solution of the water-soluble carbazide derivative L2 was 8.88 × 10⁻⁶. -6 M.

19. The method as described in claim 17, characterized in that, The sample to be tested is dissolved in a solvent; the solvent used to dissolve the sample to be tested is at least one of the same solvents used to detect the water-soluble carbazide derivative L2 of the sample to be tested.

20. The method as described in claim 17, characterized in that, The excitation wavelength of the fluorescence emission spectrum of the water-soluble carbazide derivative L2 probe is 330 nm.

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