2-aminothiazolyl rhodamine 6G derivative as well as preparation method and application thereof

Abstract

The invention belongs to an advanced material technology, and relates to a novel rhodamine derivative, in particular to a 2-aminothiazolyl rhodamine 6G derivative as well as a preparation method and application thereof. Rhodamine 6G and 2-aminothiazole are used as raw materials, the 2-aminothiazolyl rhodamine 6G derivative RGAT is prepared through a one-step reaction, on one hand, RGAT shows excellent selectivity and very high sensitivity to Fe < 3 + >, fluorescence enhancement is remarkable, the linear range of Fe < 3 + > is wide, in the Fe < 3 + > concentration range of 0-50 M, a good linear relation with the Fe < 3 + > concentration is shown, and the detection limit is as low as 2.4 nM; on the other hand, the RGAT has better antibacterial performance on gram-positive bacteria and gram-negative bacteria than commercially available bleaching water, and the RGAT is very low in cytotoxicity, so that the RGAT has a good application prospect in the fields of environmental monitoring and biological medicine.

Description

Technical Field

[0001] The present invention belongs to advanced material technology and relates to a new rhodamine derivative, in particular to a 2-aminothiazolyl rhodamine 6G derivative and a preparation method and application thereof. Background Art

[0002] Rhodamine and its derivatives are a class of classic fluorescent dyes. Due to their excellent photophysical properties such as large molar extinction coefficient, high fluorescence quantum yield, and long absorption and emission wavelengths, they are widely used as spectral probes in analytical science, environmental testing, biomedicine and other fields [Wang Y, Wang X, Ma W, et al. Recent developments inrhodamine-based chemosensors: A review of the years 2018–2022[J].Chemosensors, 2022, 10(10): 399].

[0003] Fe 3+ It is a trace element necessary for maintaining life processes. Too much or too little will affect human health. 3+ The monitoring of metal ions is very important. Spectroscopic probe method is a common method for monitoring metal ions. 3+ The research on spectral probes is very active. For example, Yin et al. synthesized a Fe-based 3+ Fluorescent probe, reacts with Fe in methanol 3+ After binding, the fluorescence increased by about 193 times, Fe 3+ The linear range is 4-12 μM, and the detection limit is 4.3 μM [Yin W, Cui H, Yang Z, et al. Facilesynthesis and characterization of rhodamine-based colorimetric and “off–on”fluorescent chemosensor for Fe 3+ [J]. Sensors and Actuators B: Chemical, 2011,157(2): 675-680]. She et al. synthesized a rhodamine-type Fe 3+ Fluorescent probe, in methanol solution with Fe 3+ After binding, the fluorescence intensity increased by 64 times, and Fe 3+The linear range is 5-20 μM, and the detection limit is 5 μM [She M, Yang Z, Yin B, et al. A novel rhodamine-based fluorescent and colorimetric “off–on” chemosensor and investigation of the recognizing behavior towards Fe 3+ [J]. Dyes and Pigments, 2012, 92(3): 1337-1343]. Zhang et al. first chlorinated rhodamine B with trichlorinated phosphorus oxychloride, and then dehydrochlorinated and condensed it with 2-aminothiazole to synthesize a Fe 3+ Spectroscopic probe, Fe-bound in CH3CN / H2O (1 / 1, v / v) 3 + The fluorescence intensity increased by about 20 times. 3+ The linear range is 2-7 μM [Zhang F, Gao Q, Zhao J, et al. Design and synthesis of a novel rhodamine-based chemosensor and recognition studies to Fe 3+ [J]. Heterocyclic Communications, 2016, 22(1): 37-42].

[0004] These reported Fe 3+ Some spectral probes require the use of highly volatile and toxic organic solvents such as methanol as detection media, some have complex synthesis processes and narrow linear ranges, some have low fluorescence enhancement multiples, high detection limits, and are not sensitive enough; moreover, these rhodamine derivatives can only detect Fe 3+ single function. Summary of the invention

[0005] If rhodamine derivatives can have multiple functions at the same time, it is more important than being able to detect only one metal ion. Therefore, the research on multifunctional rhodamine derivatives has attracted more and more attention. At present, most reports are about a probe recognizing multiple ions or molecules, which are multifunctional in the same field. Rhodamine derivatives with multifunctionality in different fields have not been reported. The present invention synthesizes a new multifunctional rhodamine 6G derivative RGAT by a one-step method. On the one hand, RGAT has a strong affinity for Fe 3+ It exhibits excellent selectivity and high sensitivity, with significant fluorescence enhancement. 3+ Wide linear range, from 0-50 µM Fe3+ Concentration range, with Fe 3+ The concentration showed a good linear relationship, and the detection limit was as low as 2.4 nM; on the other hand, RGAT had better antibacterial properties against both Gram-positive and Gram-negative bacteria than commercially available bleach, and the cytotoxicity of RGAT was very low, showing its good application prospects in environmental monitoring and biomedicine.

[0006] The present invention adopts the following technical scheme.

[0007] A 2-aminothiazolyl rhodamine 6G derivative, whose chemical structure is as follows: .

[0008] The invention discloses a preparation method of the 2-aminothiazolyl rhodamine 6G derivative, comprising the following steps: using rhodamine 6G and 2-aminothiazole as raw materials, and preparing the 2-aminothiazolyl rhodamine 6G derivative by a one-step reaction.

[0009] In the present invention, the reaction is carried out in an inert atmosphere, preferably, the inert atmosphere includes a nitrogen atmosphere.

[0010] In the present invention, the reaction temperature is 50-100° C., and the reaction time is 2-20 hours; preferably, the reaction temperature is 65-85° C., and the reaction time is 7-14 hours.

[0011] The present invention discloses the above-mentioned 2-aminothiazolyl rhodamine 6G derivative as Fe 3+ Application of spectral probes.

[0012] The present invention discloses the above-mentioned 2-aminothiazolyl rhodamine 6G derivative in the preparation of Fe 3+ Application of detection reagents.

[0013] The invention discloses the application of the 2-aminothiazolyl rhodamine 6G derivative as an antibacterial agent.

[0014] The invention discloses application of the 2-aminothiazolyl rhodamine 6G derivative in preparing an antibacterial agent.

[0015] The invention discloses a Fe 3+ The detection method comprises the following steps: using the above-mentioned 2-aminothiazolyl rhodamine 6G derivative to detect Fe 3+ Specifically, the method comprises the following steps: mixing the above 2-aminothiazolyl rhodamine 6G derivative with the system to be detected, and detecting Fe by spectroscopy. 3+ .

[0016] In the present invention, the spectrum detection includes one or both of ultraviolet-visible spectrum detection and fluorescence spectrum detection.

[0017] In the present invention, the solvent system for spectral detection includes an organic solvent and water; wherein the organic solvent includes acetonitrile, N,N-dimethylformamide (DMF), etc., preferably acetonitrile.

[0018] Preferably, the volume ratio of the organic solvent to water is 1: (1-10); more preferably, the volume ratio of the organic solvent to water is 1: (1-8); more preferably, the volume ratio of the organic solvent to water is 1: (2-6).

[0019] The present invention discloses an antibacterial method, comprising the following steps, using the above-mentioned 2-aminothiazolyl rhodamine 6G derivative for antibacterial purposes. Specifically, the method comprises the following steps, mixing the above-mentioned 2-aminothiazolyl rhodamine 6G derivative with a system containing bacteria to achieve antibacterial effects.

[0020] In the present invention, bacteria include one or more of Gram-positive bacteria and Gram-negative bacteria.

[0021] Specifically, Gram-positive bacteria include Staphylococcus, Enterococcus, Streptococcus, Bacillus, Corynebacterium, etc.; Gram-negative bacteria include Klebsiella, Escherichia coli, Pseudomonas aeruginosa, Haemophilus influenzae, Salmonella, etc. As an example, the antibacterial ability of the present invention against Bacillus thuringiensis and Serratia marcescens is better than that of commercially available bleach, and the RGAT cytotoxicity is very low, showing its good application prospects in environmental monitoring and biomedicine.

[0022] Currently, most reports are that one probe recognizes multiple ions or molecules and is multifunctional in the same field. Rhodamine derivatives with multifunctionality in different fields have not been reported. The present invention synthesizes a novel multifunctional rhodamine 6G derivative RGAT by a one-step method. On the one hand, RGAT can detect Fe 3+ It exhibits excellent selectivity and high sensitivity, with significant fluorescence enhancement. 3+ Wide linear range, from 0-50 µM Fe 3+ Concentration range, with Fe 3+ The concentration showed a good linear relationship, and the detection limit was as low as 2.4 nM; on the other hand, RGAT had better antibacterial properties against both Gram-positive and Gram-negative bacteria than commercially available bleach, and the cytotoxicity of RGAT was very low, showing its good application prospects in environmental monitoring and biomedicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the synthesis of 2-aminothiazolyl rhodamine 6G derivative (RGAT); Figure 2The response photos of RGAT (10 µM) to 17 metal ions in DMF / H2O (1 / 99, v / v) solvent system, top: natural light, bottom: 365 nm ultraviolet light, metal ion concentration: 50 µM.

[0024] Figure 3 UV-visible spectra (a) and fluorescence spectra (b) of RGAT for metal ions, solvent: DMF / H2O (1 / 99, v / v); RGAT concentration: 10 µM; metal ion concentration: 50 µM; excitation wavelength: 530 nm; slit width: 2.5 nm.

[0025] Figure 4 The response photos of RGAT (10 µM) to 17 metal ions in CH3CN / H2O (20 / 80, v / v) solvent system, top: natural light, bottom: 365 nm ultraviolet light, metal ion concentration: 50 µM.

[0026] Figure 5 UV-visible spectra (a) and fluorescence spectra (b) of RGAT for metal ions, solvent: CH3CN / H2O (20 / 80, v / v); RGAT concentration: 10 µM; metal ion concentration: 50 µM; excitation wavelength: 530 nm; slit width: 2.5 nm.

[0027] Figure 6 The expression of RGAT in response to different concentrations of Fe 3+ UV-visible absorption (a) and fluorescence intensity (b) spectra of Fe 3+ Relationship between the concentration of and the absorbance at 530 nm / fluorescence intensity at 554 nm; solvent: CH3CN / H2O (20 / 80, v / v); RGAT concentration: 10 µM; metal ion concentration: 0-150 µM; excitation wavelength: 530 nm, slit width: 2.5 nm.

[0028] Figure 7 For the coexisting metal ions, RGAT-Fe 3+ Effect of solution absorbance at 530 nm (a) and fluorescence intensity at 554 nm (b); concentration: RGAT 10 µM, Fe 3+ is 50 µM; solvent system: CH3CN / H2O (20 / 80, v / v); absorption wavelength: 530 nm, excitation wavelength: 530 nm, slit width: 2.5 nm, fluorescence wavelength: 554 nm.

[0029] Figure 8 RGAT-Fe 3+Time response of UV-visible absorption (a) and fluorescence intensity (b) of the solution; concentration: RGAT 10 µM, Fe 3+ is 50 µM; solvent system: CH3CN / H2O (20 / 80, v / v); absorption wavelength: 530 nm, excitation wavelength: 530 nm, slit width: 2.5 nm, fluorescence wavelength: 554 nm.

[0030] Fig. 9 Fe detection for RGAT 3+ UV-visible absorption (a) and fluorescence spectra (b); Concentration: RGAT 10 µM, Fe 3+ =50 µM, EDTA 60 µM; solvent: CH3CN / H2O (20 / 80, v / v); excitation wavelength: 530 nm, slit width: 2.5 nm; inset: Fe was added to CH3CN / H2O (20 / 80, v / v) solution of RGAT 3+ Then, excessive EDTA solution was added, and the color of the solution under visible light and the fluorescence change under 365 nm ultraviolet light were plotted as follows: a: natural light, b: 365 nm ultraviolet light.

[0031] Fig.10 is the survival rate of cik cells incubated with 20, 40, and 60 μM RGAT.

[0032] Fig.11 These are photos of the quantitative killing experiment of RGAT suspension, where a: Bacillus thuringiensis + sterile water; b: Bacillus thuringiensis + DMSO; c, d, e, f, g: Bacillus thuringiensis + RGAT solution, where the RGAT concentrations are 1.6 (c), 1.7 (d), 1.8 (e), 1.9 (f), 2.0 (g) mg / mL, respectively; h: Bacillus thuringiensis + bleach, the bleach concentration is 2.0 mg / mL.

[0033] Fig.12 These are photos of the quantitative killing experiment of RGAT suspension; among them, a: Serratia marcescens + sterile water; b: Serratia marcescens + DMSO; c, d, e, f, g: Serratia marcescens + RGAT solution, in which the RGAT concentrations were 1.6 (c), 1.7 (d), 1.8 (e), 1.9 (f), 2.0 (g) mg / mL, respectively; h: Serratia marcescens + bleach, the bleach concentration was 2.0 mg / mL. DETAILED DESCRIPTION

[0034] The present invention synthesizes a novel multifunctional rhodamine 6G derivative RGAT by a one-step method. On the one hand, RGAT has a strong affinity for Fe 3+ It exhibits excellent selectivity and high sensitivity, with significant fluorescence enhancement.3+ Wide linear range, from 0-50 µM Fe 3 + Concentration range, with Fe 3+ The concentration showed a good linear relationship, and the detection limit was as low as 2.4 nM; on the other hand, RGAT had better antibacterial properties against both Gram-positive and Gram-negative bacteria than commercially available bleach, and the cytotoxicity of RGAT was very low, showing its good application prospects in environmental monitoring and biomedicine.

[0035] See also Figure 1 The present invention uses rhodamine 6G and 2-aminothiazole as raw materials to react and prepare 2-aminothiazolyl rhodamine 6G derivatives. Specifically, rhodamine 6G and sodium acetate (or N,N-diisopropylethylamine) are dissolved in a solvent, 2-aminothiazole is added under N2 protection, and reflux reaction is carried out. After the reaction is completed, the reaction solution is cooled to room temperature, the solvent is removed under reduced pressure, and the crude product is separated by silica gel column chromatography to obtain a granular product with a yield of 13.2%-71.1%.

[0036] In the present invention, the molar ratio of rhodamine 6G to 2-aminothiazole is 1:(0.5-3), preferably, the molar ratio of rhodamine 6G to 2-aminothiazole is 1:(1-2.5).

[0037] In the present invention, the reflux reaction time is 1 to 20 hours, preferably 5 to 15 hours.

[0038] In the present invention, the molar ratio of rhodamine 6G to sodium acetate is 1:(1-3), preferably, the molar ratio of rhodamine 6G to sodium acetate is 1:(1.5-2.5).

[0039] In the present invention, the molar ratio of rhodamine 6G to N,N-diisopropylethylamine is 1:(1-3), preferably, the molar ratio of rhodamine 6G to N,N-diisopropylethylamine is 1:(1.5-2.5).

[0040] In the present invention, the solvent includes acetonitrile and ethanol.

[0041] The creativity of the present invention lies in the design and synthesis of a new type of rhodamine 6G derivative, which can be used as a Fe 3+ The spectral probe is a rhodamine 6G derivative with antibacterial properties.

[0042] The invention discloses a chemical structure and a synthesis method of a rhodamine 6G derivative and a method for synthesizing the rhodamine 6G derivative in Fe 3+ The invention has the following advantages: RGAT is easy to synthesize and has multiple functions in different fields: it can recognize Fe 3+and antibacterial; and RGAT as a Fe 3+ The spectral probe has good selectivity and high sensitivity; in particular, RGAT has almost no cytotoxicity; unexpectedly, RGAT has excellent antibacterial properties, which are better than commercially available bleach.

[0043] The following is a detailed description of the technical progress of the present invention. The raw materials (cells, bacteria) used are all commercially available products, and the specific preparation operations and performance tests are conventional techniques. The preparation of metal ions is a conventional technique in the art and does not affect the understanding of the technical effects of the present invention by those skilled in the art. 3+ , Fe 2+ Cr 3+ , Ag + , Cu 2+ , Al 3+ 、 + , K + Mg 2+ , Ca 2+ , Hg 2+ 、Zn 2+ 、Co 2+ 、Cd 2+ , Pb 2+ , Mn 2+ 、Ni 2+ Compounds corresponding to metal ion solutions: anhydrous FeCl3, FeCl2·7H2O, CrCl3·6H2O, AgNO3, CuSO4·5H2O, AlCl3·6H2O, NaCl, KCl, MgCl2, CaCl2, HgCl2, Zn(NO3)2·6H2O, CoCl2·6H2O, CdCl2·2.5H2O, Pb(NO3)2, MnSO4·H2O, Ni(NO3)2·6H2O.

[0044] Example 1 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile and stirred under N2 protection. Then 2-aminothiazole (0.02 g, 0.2 mmol) was added and refluxed at 75 °C for 11 h to stop the reaction. The reaction solution was naturally cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 35.2 mg of light pink granular product with a yield of 71.1%.

[0045] The molecular formula of RGAT is C 29 H 28N4O2S, molecular weight M is 496.00. Mass spectrometry analysis found that the peak with a mass-to-charge ratio of 497.09 is [M+H] of RGAT + Molecular ion peak. Then the sample was analyzed by infrared spectroscopy, and the characteristic absorption peak of RGAT structure (ν / cm -1 ): ν(COC): 1243.96; ν(Ar-H): 1416.07, 1519.64, 745.80; ν(CN): 1376.05; ν(C=O): 1621.09; ν(C=N): 1693.44; ν(CSC): 1059.31; ν(CH3,CH2): 2998.47, 2914.62. The sample was further analyzed by nuclear magnetic hydrogen spectrum, and the following data were obtained: 1 H NMR (400 MHz, CDCl3, δ / ppm): 8.04 (dd, J = 5.9, 1H, PhH), 7.57-7.49 (t, J = 3.5 Hz, 2H, PhH, SCHCHN), 7.22 (d, J =3.3 Hz, 1H, PhH)), 7.15-7.10 (m, 1H, SCHCHN), 6.79 (d, J = 3.2 Hz, 1H, PhH), 6.42 (s, 2H, PhH), 6.17 (s, 2H, PhH), 3.45 (s, 2H, CH3CH2NH), 3.24-3.16 (m,4H, CH3CH2NH), 1.83 (s, 6H, PhCH3), 1.31 (t, J = 7.2 Hz, 6H, CH3CH2NH). The results of mass spectrometry, infrared spectrum and H-NMR spectrum analysis proved that the sample was RGAT.

[0046] Example 2 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of ethanol, stirred under N2 protection, 2-aminothiazole (0.015 g, 0.15 mmol) was added, and the reaction was refluxed at 75 °C for 11 h. The reaction was stopped, the reaction solution was cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 6.5 mg of light pink granular product with a yield of 13.2%.

[0047] Example 3 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and N,N-diisopropylethylamine (DIPEA) (35 μL, 0.2 mmol) were dissolved in 8 mL of acetonitrile. After stirring under N2 protection, 2-aminothiazole (0.015 g, 0.15 mmol) was added. The reaction was refluxed at 75 °C for 11 h. The reaction was stopped, and the reaction solution was cooled to room temperature. The solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 18.3 mg of light pink granular product with a yield of 36.8%.

[0048] Example 4 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile, stirred under N2 protection, and 2-aminothiazole (0.025 g, 0.25 mmol) was added. The reaction was refluxed at 75 °C for 11 h to stop the reaction. The reaction solution was cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as the eluent to obtain 34.4 mg of light pink granular product with a yield of 69.4%.

[0049] Example 5 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile and stirred under N2 protection. 2-Aminothiazole (0.01 g, 0.1 mmol) was added and refluxed at 75 °C for 11 h. The reaction was stopped and the reaction solution was cooled to room temperature. The solvent was removed under reduced pressure and the crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 28.6 mg of light pink granular product with a yield of 57.7%.

[0050] Example 6 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile. After stirring under N2 protection, 2-aminothiazole (0.015 g, 0.15 mmol) was added. The reaction was refluxed at 75 °C for 11 h. The reaction was stopped, and the reaction solution was cooled to room temperature. The solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 32.1 mg of light pink granular product with a yield of 64.7%.

[0051] Example 7 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile, stirred under N2 protection, 2-aminothiazole (0.02 g, 0.2 mmol) was added, and the reaction was refluxed at 65 °C for 11 h. The reaction was stopped, the reaction solution was cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 30.8 mg of light pink granular product with a yield of 62.1%.

[0052] Example 8 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile, stirred under N2 protection, 2-aminothiazole (0.02 g, 0.2 mmol) was added, and the reaction was refluxed at 85 °C for 11 h. The reaction was stopped, the reaction solution was cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 32.5 mg of light pink granular product with a yield of 65.6%.

[0053] Example 9 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile, stirred under N2 protection, 2-aminothiazole (0.02 g, 0.2 mmol) was added, and the reaction was refluxed at 75 °C for 7 h. The reaction was stopped, the reaction solution was cooled to room temperature, and the solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 32.9 mg of light pink granular product with a yield of 66.3%.

[0054] Example 10 Synthesis of RGAT Rhodamine 6G (0.048 g, 0.1 mmol) and sodium acetate (CH3COOONa) (0.016 g, 0.2 mmol) were dissolved in 8 mL of acetonitrile. After stirring under N2 protection, 2-aminothiazole (0.02 g, 0.2 mmol) was added. The reaction was refluxed at 75 °C for 14 h. The reaction was stopped, and the reaction solution was cooled to room temperature. The solvent was removed under reduced pressure. The crude product was separated by silica gel column chromatography using ethyl acetate / petroleum ether = 1 / 4 (v / v) as eluent to obtain 34.8 mg of light pink granular product with a yield of 70.2%.

[0055] Example 11 Response of RGAT to metal ions In order to explore the response of RGAT to metal ions, RGAT was subjected to the addition of Fe 3+ , Fe 2+ Cr 3+ , Ag + , Cu 2+ , Al 3+ 、 + , K + Mg 2+ , Ca 2+ , Hg 2+ 、Zn 2+ 、Co 2+ 、Cd 2+ , Pb 2+ , Mn 2+ 、Ni 2+ The color, fluorescence, UV-visible spectrum and fluorescence spectrum of the solutions before and after the treatment of 17 metal ions were analyzed, and the results are as follows.

[0056] Figure 2 The color of RGAT in DMF / H2O (1 / 99, v / v) solution under visible light and fluorescence under 365 nm UV light before and after adding metal ions. It can be seen that the color of the solution did not change significantly and did not show fluorescence.

[0057] Figure 3 The UV-visible absorption spectra of RGAT in DMF / H2O (1 / 99, v / v) solution before and after adding metal ions ( Figure 3 a) and fluorescence spectra ( Figure 3 As shown in Figure b), the 17 metal ions did not cause significant changes in the UV-visible and fluorescence spectra of RGAT, indicating that in the DMF / H2O (1 / 99, v / v) system, RGAT did not respond significantly to the 17 metal ions.

[0058] Example 12 Response of RGAT to Metal Ions In order to explore the response of RGAT to metal ions, RGAT was subjected to the addition of Fe 3+ , Fe 2+ Cr 3+ , Ag + , Cu 2+ , Al 3+ 、 + , K + Mg 2+ , Ca 2+ , Hg 2+ 、Zn2+ 、Co 2+ 、Cd 2+ , Pb 2+ , Mn 2+ 、Ni 2+ The color, fluorescence, UV-visible spectrum and fluorescence spectrum of the solutions before and after the treatment of 17 metal ions were analyzed, and the results are as follows.

[0059] Figure 4 The color under visible light and the fluorescence under 365 nm UV light are shown in CH3CN / H2O (20 / 80, v / v) solution of RGAT before and after adding metal ions. 3+ The CH3CN / H2O (20 / 80, v / v) solution of RGAT turns red and emits yellow-green fluorescence.

[0060] Figure 5 The UV-visible absorption spectra of RGAT in CH3CN / H2O (20 / 80, v / v) solution before and after adding metal ions ( Figure 5 a) and fluorescence spectra ( Figure 5 b). From Figure 5 It can be found in a that Fe 3+ The RGAT solution showed an absorption peak at 530 nm, with an absorbance enhancement factor of 24 times, which corresponds to the color observed by the naked eye, while other ions did not cause significant changes in the UV-visible absorption spectrum of the RGAT solution. Figure 5 In b, it can be found that Fe 3+ The fluorescence of RGAT at 554 nm was enhanced by 69 times, and other ions did not significantly change the fluorescence spectrum of RGAT solution. Therefore, in the CH3CN / H2O (20 / 80, v / v) system, the UV-visible absorption and fluorescence spectra of RGAT were significantly different from those of Fe 3+ Has a highly selective response.

[0061] Example 13 RGAT absorption and fluorescence spectra and Fe 3+ The relationship between concentration In order to explore the relationship between RGAT absorption and fluorescence spectra and Fe 3+ The relationship between the concentration of RGAT and the addition of different concentrations of Fe 3+ The UV-visible absorption and fluorescence spectra are shown in Figure 2. Figure 6 As shown. 3+ As the concentration gradually increased, the absorbance of RGAT at around 530 nm ( Figure 6 a) and the fluorescence intensity near 554 nm ( Figure 6b) gradually increased, and in the range of 0 to 50 µM Fe 3+ Concentration range, with Fe 3+ The concentration showed a good linear relationship, and the linear equations of absorbance and fluorescence intensity were A=0.00227×[Fe 3+ ]–0.01093 and F=16.239101×[Fe 3+ ]–18.34921, with correlation coefficients of 0.997 and 0.997, respectively. Fe was detected by UV-visible absorption spectroscopy and fluorescence spectroscopy. 3+ The detection limits were 1.8×10 -6 mol / L and 2.4×10 -9 mol / L.

[0062] Example 14 RGAT detection of Fe 3+ Anti-interference In order to investigate the detection of Fe in CH3CN / H2O (20 / 80, v / v) system, RGAT 3+ The anti-interference ability of other coexisting ions is 3+ Al 3+ Cr 3+ , Fe 2+ , Ag + , Cu 2+ 、 + , K + Mg 2+ , Ca 2+ , Hg 2+ 、Zn 2+ 、Co 2+ 、Cd 2+ , Pb 2+ , Mn 2+ 、Ni 2+ One of them is to compare the UV-visible absorption and fluorescence spectra of the solution before and after adding these ions. Figure 7 As shown, after adding other interfering ions, the absorbance at 530 nm ( Figure 7 (a) or the fluorescence intensity near 554 nm ( Figure 7 Therefore, RGAT detects Fe in CH3CN / H2O (20 / 80, v / v) system. 3+ It has strong anti-interference ability.

[0063] Example 15 RGAT detection of Fe 3+ Time responsiveness In order to investigate the detection of Fe in CH3CN / H2O (20 / 80, v / v) system, RGAT 3+The response speed of Fe 3+ Start and record the UV-visible absorption and fluorescence spectra of the solution at certain intervals, such as Figure 8 .Depend on Figure 8 From a, we can see that adding Fe 3+ The absorbance of the RGAT solution increased significantly within 7 minutes and reached a stable state after 8 minutes. Figure 8 As can be seen from b, adding Fe 3+ The fluorescence intensity of the RGAT solution increased rapidly to a maximum and stabilized within 30 min. Therefore, RGAT has the potential to rapidly detect Fe in the CH3CN / H2O (20 / 80, v / v) system. 3+ ability.

[0064] Example 16 RGAT detection of Fe 3+ Reversibility Fe was added to the CH3CN / H2O (20 / 80, v / v) solution of RGAT. 3+ Then, 60 μM EDTA solution was added to investigate the ability of RGAT to detect Fe 3+ The reversibility of Fig. 9 .Depend on Fig. 9 From a, we can see that Fe is added to the RGAT solution. 3+ After adding EDTA, the solution color changed from colorless to pink. After adding EDTA, the solution color changed from pink to colorless. 3+ After the solution was analyzed for absorbance, an absorption peak was found at 530 nm. The absorbance value decreased to a value close to the original absorbance value of RGAT by adding EDTA solution. Therefore, RGAT colorimetric detection of Fe 3+ It is reversible. Fig. 9 From b, we can see that Fe is added to the RGAT solution. 3+ The solution showed yellow fluorescence, and the fluorescence was quenched by adding EDTA solution. 3+ The fluorescence intensity of the solution was analyzed and it was found that the addition of Fe 3+ , the fluorescence of the solution was significantly enhanced. After adding excess EDTA solution, the fluorescence intensity at 554 nm decreased significantly and basically returned to the original fluorescence intensity of RGAT. 3+ It is a reversible process, which lays the foundation for the recycling of probes.

[0065] Example 17 Practicality of RGAT To investigate the practicability of RGAT, the pond water and tap water of the Dushu Lake Campus of Soochow University were spiked and analyzed using RGAT according to the conventional method.3+ Fluorescence emission spectrum of RGAT solution. 3+ The linear relationship between the concentration of Fe 3+ Concentration, Fe 3+ The recovery rate and relative standard deviation are shown in Table 1: 3+ Concentration and added Fe 3+ The concentrations are similar, Fe 3+ The recovery rate was between 96.10% and 102.45%, and the relative standard deviation of three parallel experiments was less than 1.21%. Therefore, RGAT can be used to effectively analyze Fe in actual environmental water samples. 3+ .

[0066] Table 1 Determination of Fe in pond water and tap water by RGAT 3+ (n=3)

[0067] Solvent system: CH3CN / H2O (20 / 80, v / v), RGAT concentration: 10 µM, RSD: relative standard deviation.

[0068] Example 18 Toxicity of RGAT Cytotoxicity assay method: 100 μL of cell suspension (about 5000 cells / well) was inoculated into each well of a 96-well plate. The plate was pre-cultured in an incubator at 37 °C (5% CO2) for 24 h, then 10 μL of CCK-8 solution was added to each well of the plate, the plate was incubated in the incubator for 1 h, and finally 1 μL of different concentrations of the test substance RGAT (solvent: CH3CN) was added to the well, the plate was incubated in the incubator for 24 h, and the absorbance at 450 nm was measured using a microplate reader.

[0069] Cytotoxicity assay results: The cytotoxicity of RGAT measured by microplate reader is as follows Fig.10 As shown. The survival rate of cells not treated with RGAT was set as 100%, and the survival rates of cells treated with 20, 40, and 60 μM RGAT were 100.02%, 100.96%, and 101.35%, respectively, indicating that RGAT had no negative impact on the survival rate of grass carp kidney cells (cik). Therefore, RGAT has very low cytotoxicity and can be used in biological samples.

[0070] Example 19 Antibacterial properties of RGAT Antibacterial activity determination method: Take 16 1 mL EP tubes and number them from 1 to 16. Add 50 μL of Bacillus thuringiensis standard solution (Bio-52496) to tubes 1 to 8, and then add 50 μL of sterile water, 50 μL of DMSO solvent, 50 μL of 1.6, 1.7, 1.8, 1.9, 2.0 mg / mL RGAT antibacterial solution (solvent is DMSO) and 50 μL of 2.0 mg / mL bleach. Add 50 μL of Serratia marcescens standard solution (Bio-72774) to tubes 9 to 16, and then operate the same as tubes 1 to 8. Mix quickly and record the time immediately. When the test bacteria interact with the disinfectant for 30 minutes, add the sterilized neutralizer and mix well to stop the reaction. After 10 min, take 50 μL of the uniformly mixed reaction solution into the culture dishes with the same number containing LB culture medium, heat the coating stick over the flame of an alcohol lamp to sterilize it, then dip the reaction solution and spread it evenly on the LB culture medium, seal it with a sealing film, and place it in a biochemical box at 37 ℃ for natural growth for 24 h, and take pictures and record.

[0071] Antibacterial test results: The antibacterial properties of RGAT measured by suspension quantitative killing test are as follows Fig.11 and 12 As shown. Under suitable growth conditions, Bacillus thuringiensis (Gram-positive bacteria, Fig.11 a) and Serratia marcescens (Gram-negative bacteria, Fig.12 a) grows and multiplies all over the surface of the culture medium. DMSO organic solvent has an effect on Bacillus thuringiensis ( Fig.11 b) and Serratia marcescens ( Fig.12 The growth of Bacillus thuringiensis (b) was slightly affected, and the surface of the culture medium was also covered, with almost no significant difference from the growth phenomenon under normal conditions. Analysis of the effects of different concentrations of RGAT antibacterial solution showed that: when the concentration of RGAT solution was 1.6 mg / mL, Bacillus thuringiensis ( Fig.11 c) A small number of large white round colonies grow on the surface of the culture medium, Serratia marcescens ( Fig.12 c) A small number of white tiny colonies survived on the surface of the culture medium. In the process of gradually increasing the concentration of the RGAT solution to 2.0 mg / mL, it was observed that the antibacterial effect gradually increased with the increase of the concentration of the RGAT solution ( Fig.11 1.9 mg / mL RGAT solution was mixed with 2.0 mg / mL bleach ( Fig.11 12 h and 12 h) had similar sterilization effects, and Bacillus thuringiensis ( Fig.11 f) and Serratia marcescens ( Fig.12f) No colonies grew on the surface of the culture medium. Therefore, RGAT has a strong inhibitory effect on the growth and reproduction of Gram-positive and Gram-negative bacteria, and RGAT has better antibacterial properties against Gram-positive and Gram-negative bacteria than commercially available bleach.

Claims

1. A 2-aminothiazolyl rhodamine 6G derivative, whose chemical structure is as follows: 。 2. The method for preparing the 2-aminothiazolyl rhodamine 6G derivative according to claim 1, characterized in that: The method comprises the following steps: taking rhodamine 6G and 2-aminothiazole as raw materials, and preparing a 2-aminothiazolyl rhodamine 6G derivative by one-step reaction.

3. The method for preparing the 2-aminothiazolyl rhodamine 6G derivative according to claim 2, characterized in that: The reaction is carried out in an inert atmosphere; the reaction temperature is 50-100° C. and the reaction time is 2-20 hours.

4. The 2-aminothiazolyl rhodamine 6G derivative of claim 1 as Fe 3+ Application of spectral probes.

5. The 2-aminothiazolyl rhodamine 6G derivative according to claim 1 is used in the preparation of Fe 3+ Application of detection reagents.

6. Use of the 2-aminothiazolyl rhodamine 6G derivative according to claim 1 as an antibacterial agent, or use of the 2-aminothiazolyl rhodamine 6G derivative according to claim 1 in the preparation of an antibacterial agent.

7. A kind of Fe 3+ The detection method is characterized in that The method comprises the following steps: using the 2-aminothiazolyl rhodamine 6G derivative according to claim 1 to detect Fe 3+ .

8. Fe according to claim 7 3+ The detection method is characterized in that Spectral detection includes one or both of ultraviolet-visible spectral detection and fluorescence spectral detection.

9. An antibacterial method, comprising the following steps: using the 2-aminothiazolyl rhodamine 6G derivative of claim 1 for antibacterial purposes.

10. The antibacterial method according to claim 9, characterized in that: The bacteria include one or more of Gram-positive bacteria and Gram-negative bacteria.

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