A type of Fe 3+ and Cr 3+ Rhodamine-like fluorescent probes with dual-response thiophene structures, their synthesis methods and applications

Abstract

This invention discloses three methods for reacting with Fe 3+ and Cr 3+ This invention relates to thiophene-containing probes with dual responses and their applications, belonging to the field of organic small molecule fluorescent probes. The probes are labeled FS-1, FS-2, and FS-3. Specifically, probe FS-1, under an excitation spectrum of 555 nm in acetonitrile solution, reacts with Fe... 3+ and Cr 3+ The binding caused a dramatic increase in fluorescence intensity at 584 nm; the FS-2 probe pair, in acetonitrile solution, under an excitation spectrum of 530 nm, reacted with Fe... 3+ and Cr 3+ The binding caused a sharp increase in fluorescence intensity at 555 nm; the FS-3 probe, in acetonitrile solution, under an excitation spectrum of 560 nm, reacted with Fe... 3+ and Cr 3+ The binding caused a sharp increase in fluorescence intensity at 584 nm in the fluorescence spectrum. All three probes were effective against Fe. 3+ and Cr 3+ It has high sensitivity, which is beneficial for detecting food containing these heavy metal ions and for playing a role in environmental monitoring.

Description

Technical Field

[0001] This invention belongs to the field of organic small molecule fluorescent probe technology, specifically relating to a probe for Fe... 3+ and Cr 3+ Rhodamine-based fluorescent probes with dual responses and containing thiophene structures, their synthesis methods, and applications. Background Technology

[0002] Iron in nature exists primarily in compound form, exhibiting divalent or trivalent oxidation states. Driven by industrial activities, including mining, iron ions are carried into human society, present in the environment, food, and medical spheres. For humans, iron is an essential trace element, largely bound to hemoglobin for oxygen transport, with the remainder distributed among various cells involved in metabolic and physiological activities. However, industrial development has made iron pollution a major factor harming human health. As a heavy metal, excessive iron levels inevitably affect protein transport and normal cellular metabolism, leading to iron deposition and impairing normal bodily functions. Similarly, chromium ions, another heavy metal, are primarily absorbed into rivers and seas by rainwater and accumulate in the food chain. Their harm to humans is mainly through absorption via the skin and mucous membranes, entering the systemic circulation, binding to cell membrane proteins, affecting transport functions, and damaging cell membrane structure and function, leading to cerebrovascular diseases, gastrointestinal and renal dysfunction, and possessing a certain degree of carcinogenicity. Therefore, developing ion probes for detection in three environments and food is particularly important and is a key part of clinical diagnosis.

[0003] With the interdisciplinary integration of various fields, instruments and methods based on principles such as atomic absorption spectrometry, neutron activation analysis, X-ray fluorescence spectrometry, ion chromatography, and Raman spectroscopy have been developed for the detection of heavy metal ions. However, these techniques generally suffer from high costs, complex operations, and the need for large-scale instruments, which limits the detection of iron ions to some extent. Therefore, considering all aspects, the development of three highly efficient and sensitive probes is urgently needed. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a method for treating Fe 3+ and Cr 3+ Rhodamine-like fluorescent probes with dual-response thiophene structures, their synthesis methods, and applications: The fluorescent probes provided by this invention can efficiently selectively detect Fe. 3+ and Cr 3+ To achieve the control of trace amounts of Fe 3+ and Cr 3+ Visualization and high-sensitivity detection.

[0005] The technical solution of the present invention is as follows:

[0006] This invention provides a method for treating Fe 3+ and Cr 3+ A rhodamine-based fluorescent probe with a thiophene-containing structure exhibiting dual response, wherein the rhodamine-based fluorescent probe has a general formula (I) structure:

[0007]

[0008] Where R is -CHO, -CH3, or C7H5N3O1.

[0009] The present invention also provides a method for treating Fe 3+ and Cr 3+ A method for synthesizing a rhodamine-based fluorescent probe with a thiophene-containing structure exhibiting dual response includes the following steps:

[0010] (1) Rhodamine B and hydrazine hydrate were dissolved in anhydrous ethanol solution and reacted by heating. The gray solid obtained by separation and purification was compound 1, with the structure shown in (II):

[0011]

[0012] (2) Compound 1 was mixed with 2,5-thiophene dicarboxaldehyde and dissolved in ethanol solution. The mixture was refluxed and purified to obtain a yellow product, which is the fluorescent probe FS-1. Its chemical structure is shown in III.

[0013]

[0014] (3) Compound 1 was mixed with thiophene formaldehyde, dissolved in ethanol solution, and refluxed. After separation and purification, a white powder compound was obtained, which is the fluorescent probe FS-2. Its chemical structure is shown in IV.

[0015]

[0016] (4) Fluorescent probe FS-1 was mixed with 4-aminobenzoylhydrazine, dissolved in ethanol solution, and refluxed to obtain an orange product, which is fluorescent probe FS-3, with the chemical structure shown in V:

[0017]

[0018] Preferably, in step (1), the molar ratio of rhodamine B to hydrated hydrazine is 1:10.

[0019] Preferably, in step (2), the molar ratio of compound 1 to 2,5-thiophene dicarboxaldehyde is 1:1.

[0020] Preferably, in step (3), the molar ratio of compound 1 to thiophene formaldehyde is 1:2.

[0021] Preferably, in step (4), the molar ratio of the fluorescent probe to 4-aminobenzoyl hydrazine is 1:1.

[0022] Preferably, in step (1), the heating temperature is 90°C and the heating time is 12 hours.

[0023] Preferably, in step (1), the separation and purification process adopts column chromatography separation, and the eluent is a mixture of petroleum ether and ethyl acetate with a volume ratio of 2:1.

[0024] Preferably, the reflux reaction temperature in steps (2), (3) and (4) is 90°C and the reflux reaction time is 12h; the separation and purification process in step (2) adopts column chromatography, and the eluent is a mixture of petroleum ether and ethyl acetate with a volume ratio of 7:1; the separation and purification process in step (3) adopts column chromatography, and the eluent is a mixture of petroleum ether and ethyl acetate with a volume ratio of 15:1.

[0025] The present invention also provides a method for treating Fe 3+ and Cr 3+ Application of thiophene-containing fluorescent probes with dual responses in the detection of aquatic products and the environment.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) This invention is the first to design and synthesize three identifiable Fe3+ compounds. 3+ and Cr 3+ The thiophene-containing fluorescent probes FS-1, FS-2, and FS-3 provided by this invention induce a visible colorimetric response (from colorless to bright pink) in acetonitrile solution, and activate strong fluorescence, generating new spectral bands; they exhibit extremely high sensitivity, good selectivity, and stable light energy characteristics during the sensing process.

[0028] (2) Compared with existing fluorescent probe technologies, the synthesis methods of the fluorescent probes FS-1, FS-2, and FS-3 provided by this invention are simple, with considerable yield, low cost, and simple operation. Furthermore, as open-type fluorescent probes, they avoid background interference caused by objective factors, exhibiting high accuracy and can be applied to Fe in food. 3+ and Cr 3+ The safety assessment of contamination has a promising future in the field of food safety.

[0029] Figure Labels

[0030] Figure 1The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-1 synthesized in Example 1 of this invention;

[0031] Figure 2 The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-2 synthesized in Example 1 of this invention;

[0032] Figure 3 The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-3 synthesized in Example 1 of this invention;

[0033] Figure 4 The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-1 synthesized in Example 1 of this invention;

[0034] Figure 5 The image shows the carbon NMR spectrum of the thiophene-containing fluorescent probe FS-1 synthesized in Example 1 of this invention.

[0035] Figure 6 The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-2 synthesized in Example 1 of this invention;

[0036] Figure 7 The image shows the carbon NMR spectrum of the thiophene-containing fluorescent probe FS-2 synthesized in Example 1 of this invention.

[0037] Figure 8 The above is the 1H NMR spectrum of the thiophene-containing fluorescent probe FS-3 synthesized in Example 1 of this invention;

[0038] Figure 9 The image shows the carbon NMR spectrum of the thiophene-containing fluorescent probe FS-3 synthesized in Example 1 of this invention.

[0039] Figure 10 The images show the fluorescence spectra of the thiophene-containing fluorescent probe FS-1 synthesized in Example 1 of this invention in acetonitrile solution with different ions (A is the fluorescence spectrum, B is the fluorescence intensity spectrum).

[0040] Figure 11 The fluorescence spectra of the thiophene-containing fluorescent probe FS-3 synthesized in Example 1 of this invention in acetonitrile solution with different ions are shown in Figure A (fluorescence spectrum, fluorescence intensity spectrum).

[0041] Figure 12 The images show the fluorescence spectra of the thiophene-containing fluorescent probe FS-1 synthesized in Example 1 of this invention in acetonitrile solution with different ions (A is the fluorescence spectrum, B is the fluorescence intensity spectrum). Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0043] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0044] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0045] The drying solvents used in the reaction were all dried using molecular sieve type 4A (sodium-A type molecular sieve) or molecular sieve type 3A (potassium-A type molecular sieve);

[0046] Argon was used as the protective gas in all inert atmospheres used in the reaction.

[0047] 1 The H-s spectra were recorded on a JEOL ECZ600S (600MHz) spectrometer using CDCl3 as the solvent.

[0048] Based on internal TMS (trimethylsilane) reference data, a front field chemical shift of one part per million was reported;

[0049] The coupling constant (J) is expressed in Hertz (Hz), and the spin multiple states are expressed in s (singlet state), d (doublet state), t (triplet state), and m (multiplex state);

[0050] Column chromatography was performed using thick-walled glass columns and silica gel (300-400 mesh); thin-layer chromatography (TLC) was performed using commercially available 0.25 mm silica gel plates under UV light.

[0051] The ultraviolet absorption spectrum of the solution was obtained using a Shimadzu UV-1900 UV-Vis-NIR spectrophotometer.

[0052] Fluorescence spectra were measured using a Spectrofluorometer FS5 fluorescence spectrometer; mass spectra were recorded using a ThermoFisher high-performance liquid chromatography-mass spectrometry system.

[0053] Example 1

[0054] A rhodamine-based fluorescent probe containing a thiophene structure has the general formula (I) structure:

[0055]

[0056] Where R is -CHO, -CH3, or C7H5N3O1

[0057] Example 2

[0058] This embodiment provides a method for dealing with Fe 3+ and Cr3+ The chemical structure of a rhodamine-based fluorescent probe containing a thiophene structure and exhibiting dual responsiveness is shown below:

[0059]

[0060] The synthesis method of the above-mentioned fluorescent probe FS-1 includes the following steps:

[0061] (1) Rhodamine B (444.24 mg, 1.00 mM) and hydrazine hydrate (320.40 mg, 10 mM) were mixed and dissolved in anhydrous ethanol solution (10 mL). The mixture was heated at 90 °C for 12 h, and the solvent was removed by rotary evaporation under reduced pressure. The mixture was then purified using a petroleum ether / ethyl acetate mixture with a volume ratio of 2:1 to obtain a light gray powder, which was compound 1. The yield was 207.94 mg, and the yield was 45.60%. The preparation process is as follows:

[0062]

[0063] (2) Compound 1 (207.94 mg, 1 mM) was mixed with 2,5-thiophene dicarboxaldehyde (139.99 mg, 1.00 mM) and dissolved in 15 mL of ethanol solution. The mixture was refluxed at 90 °C for 12 h. The solvent was removed by rotary evaporation under reduced pressure. The product was purified by separation using a petroleum ether / ethyl acetate mixture with a volume ratio of 7:1 to obtain a yellow solid, which was probe FS-1. 333 mg of the yellow product was obtained, with a yield of 57.5%. The reaction process is as follows:

[0064]

[0065] The fluorescent probe FS-1 synthesized according to the above method was subjected to spectral characterization, including fluorescence spectral analysis in acetonitrile solvent with 20 eq of other different ions. The process included the following steps:

[0066] (1) 32 other different ions were screened out: sodium fluoride, sodium bromide, sodium iodide, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium bisulfite, sodium sulfate, sodium bicarbonate, sodium carbonate, potassium chloride, lithium hydroxide monohydrate, sodium chloride, ammonium chloride, nickel chloride, cesium carbonate, zinc chloride, calcium chloride, magnesium chloride, manganese chloride, copper sulfate pentahydrate, cerium trichloride pentahydrate, aluminum chloride, cobalt chloride, tin trichloride, cadmium sulfate, chromium trichloride hexahydrate, ferrous chloride tetrahydrate, anhydrous ferric chloride, and lead chloride;

[0067] (2) The fluorescent probe FS-1 obtained in Example 1 was dissolved in dimethyl sulfoxide solution, placed in N,N-dimethylformamide solvent, diluted to 10 μM probe buffer solution, and the fluorescence spectrum after adding 200 μM of different ions was measured. The fluorescence intensity change at 584 nm was analyzed. The conditions of the fluorescence spectrometer were the same as in step 1.

[0068] like Figure 10 As shown in AB, the probe is in acetonitrile solvent and identifies Fe. 3+ and Cr 3+ Afterward, intense fluorescence was activated, with the fluorescence intensity changing by more than two million times at the emission wavelength of 584nm.

[0069] Example 3

[0070] This embodiment provides a method for dealing with Fe 3+ and Cr 3+ The chemical structure of a rhodamine-based fluorescent probe containing a thiophene structure and exhibiting dual responsiveness is shown below:

[0071]

[0072] The synthesis method of the above-mentioned fluorescent probe FS-2 includes the following steps:

[0073] (1) Rhodamine B (444.24 mg, 1.00 mM) and hydrazine hydrate (320.40 mg, 10 mM) were dissolved in anhydrous ethanol solution (10 mL), and the mixture was heated at 90 °C for 12 h. The solvent was removed by rotary evaporation under reduced pressure. The mixture was purified by separation using a petroleum ether / ethyl acetate mixture with a volume ratio of 2:1 to obtain a light gray powder, which was compound 1, 207.94 mg, with a yield of 45.60%. The preparation process is as follows:

[0074]

[0075] (2) Compound 1 (207.94 mg, 1 mM) was mixed with thiophene formaldehyde (252.02 mg, 2 mM) and dissolved in 15 mL of ethanol solution. The mixture was refluxed at 90 °C for 12 h. The solvent was removed by rotary evaporation under reduced pressure. The product was purified by separation using a petroleum ether / ethyl acetate mixture with a volume ratio of 15:1 to obtain 511.22 mg of a white powder compound, with a yield of 90.64%. This compound was identified as probe FS-2. The reaction process is as follows:

[0076]

[0077] The fluorescent probe FS-2 synthesized according to the above method was subjected to spectral characterization, including fluorescence spectral analysis in acetonitrile solvent with 20 eq of other different ions. The steps included:

[0078] (1) 32 other different ions were screened out: sodium fluoride, sodium bromide, sodium iodide, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium bisulfite, sodium sulfate, sodium bicarbonate, sodium carbonate, potassium chloride, lithium hydroxide monohydrate, sodium chloride, ammonium chloride, nickel chloride, cesium carbonate, zinc chloride, calcium chloride, magnesium chloride, manganese chloride, copper sulfate pentahydrate, cerium trichloride pentahydrate, aluminum chloride, cobalt chloride, tin trichloride, cadmium sulfate, chromium trichloride hexahydrate, ferrous chloride tetrahydrate, anhydrous ferric chloride, and lead chloride;

[0079] (2) The fluorescent probe FS-2 obtained in Example 3 was dissolved in dimethyl sulfoxide solution, placed in acetonitrile solvent, and diluted to 10 μM probe buffer solution. The fluorescence spectrum after adding 200 μM of different ions was measured, and the fluorescence intensity change at 555 nm was analyzed. The conditions of the fluorescence spectrometer were the same as in step 1.

[0080] like Figure 11 As shown in AB, the probe is in acetonitrile solvent and identifies Fe. 3+ and Cr 3+ Afterward, intense fluorescence was activated, with the fluorescence intensity changing by more than two million times at the emission wavelength of 555nm.

[0081] Example 4

[0082] This embodiment provides a method for dealing with Fe 3+ and Cr 3+ The chemical structure of a rhodamine-based fluorescent probe containing a thiophene structure and exhibiting dual responsiveness is shown below:

[0083]

[0084] The synthesis method of the above-mentioned fluorescent probe FS-3 includes the following steps:

[0085] (1) Rhodamine B (444.24 mg, 1.00 mM) and hydrazine hydrate (320.40 mg, 10 mM) were dissolved in anhydrous ethanol solution (10 mL), and the mixture was heated at 90 °C for 12 h. The solvent was removed by rotary evaporation under reduced pressure. The mixture was purified by separation using a petroleum ether / ethyl acetate mixture with a volume ratio of 2:1 to obtain a light gray powder, which was compound 1, 207.94 mg, with a yield of 45.60%. The preparation process is as follows:

[0086]

[0087] (2) Compound 1 (207.94 mg, 1 mM) was mixed with 2,5-thiophene dicarboxaldehyde (139.99 mg, 1.00 mM) and dissolved in 15 mL of ethanol solution. The mixture was refluxed at 90 °C for 12 h. The solvent was removed by rotary evaporation under reduced pressure. The product was purified by separation using a petroleum ether / ethyl acetate mixture with a volume ratio of 7:1 to obtain a yellow solid. 333 mg of the yellow product was obtained, with a yield of 57.5%, designated as FS-1. The reaction process is as follows:

[0088]

[0089] (3) FS-1 (333 mg, 1 Mm) was mixed with 4-aminobenzoylhydrazine (151.07 mg, 1 Mm) and dissolved in ethanol solution (10 mL). The mixture was refluxed at 90 °C for 12 h to give 54 mg of orange product, with a yield of 7.6%. The reaction process is as follows:

[0090]

[0091] The fluorescent probe FS-3 synthesized according to the above method was subjected to spectral characterization, including fluorescence spectral analysis in acetonitrile solvent with 20 eq of other different ions. The steps included:

[0092] (1) 32 other different ions were screened out: sodium fluoride, sodium bromide, sodium iodide, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium bisulfite, sodium sulfate, sodium bicarbonate, sodium carbonate, potassium chloride, lithium hydroxide monohydrate, sodium chloride, ammonium chloride, nickel chloride, cesium carbonate, zinc chloride, calcium chloride, magnesium chloride, manganese chloride, copper sulfate pentahydrate, cerium trichloride pentahydrate, aluminum chloride, cobalt chloride, tin trichloride, cadmium sulfate, chromium trichloride hexahydrate, ferrous chloride tetrahydrate, anhydrous ferric chloride, and lead chloride;

[0093] (2) The fluorescent probe FS-3 obtained in Example 4 was dissolved in dimethyl sulfoxide solution, placed in acetonitrile solvent, and diluted to 10 μM probe buffer solution. The fluorescence spectrum after adding 200 μM of different ions was measured, and the fluorescence intensity change at 584 nm was analyzed. The conditions of the fluorescence spectrometer were the same as in step 1.

[0094] like Figure 12 As shown in AB, the probe is in acetonitrile solvent and identifies Fe. 3+ and Cr 3+ Afterward, intense fluorescence was activated, with the fluorescence intensity changing by more than two million times at the emission wavelength of 584nm.

[0095] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for treating Fe 3+ and Cr 3+ Rhodamine-based fluorescent probes with a thiophene-containing structure exhibiting dual response are characterized by, The rhodamine-based fluorescent probe has a general formula (I) structure: （Ⅰ） Where R is -CHO or C7H5N3O1.

2. The method for treating Fe as described in claim 1 3+ and Cr 3+ A method for synthesizing a rhodamine-based fluorescent probe with a thiophene-containing structure exhibiting dual response, characterized in that... Includes the following steps: (1) Rhodamine B and hydrazine hydrate were dissolved in anhydrous ethanol solution and reacted by heating. The gray solid was obtained by separation and purification, which is compound 1. The chemical structure is shown in Figure (II): （Ⅱ） (2) Compound 1 was mixed with 2,5-thiophene dicarboxaldehyde and dissolved in ethanol solution. The mixture was refluxed and purified to obtain a yellow product, which is the fluorescent probe FS-1. Its chemical structure is shown in III. （Ⅲ） (3) Fluorescent probe FS-1 was mixed with 4-aminobenzoylhydrazine, dissolved in ethanol solution, and refluxed to obtain an orange product, which is fluorescent probe FS-3, with the chemical structure shown in V: （V）。 3. The method for treating Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing rhodamine-based fluorescent probes with a thiophene-containing structure exhibiting dual response, characterized by: In step (1), the molar ratio of Rhodamine B to hydrazine hydrate is 1:

10.

4. The Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing thiophene-containing structures with dual responses, characterized in that: In step (2), the molar ratio of compound 1 to 2,5-thiophene dicarboxaldehyde is 1:

1.

5. The Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing thiophene-containing structures with dual responses, characterized in that: In step (3), the molar ratio of the fluorescent probe to 4-aminobenzoyl hydrazine is 1:

1.

6. The method for treating Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing thiophene-containing structures with dual responses, characterized in that: In step (1), the heating temperature is 90 ℃ and the heating time is 12 h.

7. The Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing thiophene-containing structures with dual responses, characterized in that: In step (1), the separation and purification process is carried out by column chromatography, and the eluent is a mixture of petroleum ether and ethyl acetate with a volume ratio of 2:

1.

8. The method for treating Fe as described in claim 2 3+ and Cr 3+ A method for synthesizing thiophene-containing structures with dual responses, characterized in that: In step (2), the reflux reaction temperature is 90 °C and the reflux reaction time is 12 h. In step (2), the separation and purification process adopts column chromatography separation, and the eluent is a mixture of petroleum ether and ethyl acetate with a volume ratio of 7:

1.

9. A method for treating Fe as described in claim 1 3+ and Cr 3+ Application of thiophene-containing fluorescent probes with dual responses in the detection of aquatic products and the environment.

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