Hydrogen sulfide fluorescent probe, preparation method and application thereof

Abstract

The present application relates to a kind of hydrogen sulfide fluorescent probe, preparation method and application, the hydrogen sulfide fluorescent probe has the following structural formula: Its preparation method includes the following steps: 2-(3-formyl-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid ethyl ester is dissolved in glacial acetic acid with carboxymethyl rhodanine Heating reflow reaction, after reaction is complete, cooling to room temperature, after filtration, washing and drying, obtain hydrogen sulfide fluorescent probe.The hydrogen sulfide fluorescent probe described in the present application is used for hydrogen sulfide detection.The present application can realize visual quantitative detection of hydrogen sulfide, can realize fast, sensitive in solution and solid qualitative or quantitative detection of hydrogen sulfide, has wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of polymer compound technology, and in particular to a hydrogen sulfide fluorescent probe, its preparation method and application. Background Technology

[0002] Hydrogen sulfide (H2S) is a gaseous signaling molecule that participates in multiple physiological processes and is closely related to human health. Furthermore, H2S molecules are released during food spoilage, and excessive intake of H2S can negatively impact human health. Therefore, accurate detection of H2S content in biological systems and food is of great significance.

[0003] Currently, widely used methods for H2S detection include atomic absorption spectrometry, inductively coupled plasma mass spectrometry, and electrochemical analysis. However, these methods require expensive and complex instruments and skilled professionals, resulting in cumbersome analysis processes, long analysis times, and high costs, making them unsuitable for rapid on-site H2S detection. In recent years, fluorescence detection analysis methods based on chemical sensors have attracted significant attention due to their simplicity, high selectivity and sensitivity, rapid analysis time, non-destructive nature, and convenient visual qualitative identification.

[0004] In recent years, there have been many reports on fluorescent probes for detecting H2S. However, the synthesis steps of these probes are complicated, and test strips cannot be prepared for real-time monitoring of H2S, which reduces the applicability of the probes. Summary of the Invention

[0005] Therefore, it is necessary to address the problems of cumbersome synthesis steps, low selectivity, and low sensitivity of existing probes for identifying hydrogen sulfide, and to provide a hydrogen sulfide fluorescent probe, its preparation method, and its application.

[0006] A hydrogen sulfide fluorescent probe, the structural formula of which is shown in formula (I): (I).

[0007] A method for preparing a hydrogen sulfide fluorescent probe as described above includes the following steps: Ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazol-5-carboxylic acid was dissolved in glacial acetic acid and subjected to a reflux reaction. After the reaction was complete, the mixture was cooled to room temperature, filtered, washed and dried to obtain a hydrogen sulfide fluorescent probe.

[0008] The specific reaction formula is as follows:

[0009] It should be noted that in this invention, glacial acetic acid is used as the reaction system, and the actual amount used is sufficient to dissolve all the reactants. This invention does not specify the specific amount of glacial acetic acid used.

[0010] As a preferred embodiment, the molar ratio of ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid to carboxymethyl bortanin is 1:1.1-1.3. An appropriate excess of carboxymethyl bortanin facilitates the reflux reaction without causing difficulty in removing the carboxymethyl bortanin after the reaction.

[0011] As a preferred embodiment, the heating temperature in the reflux heating is 120-130℃, and the reaction time is 5-6h.

[0012] As a preferred option, the filtered solid is washed with ethanol, and the washing process is performed at least twice.

[0013] A hydrogen sulfide fluorescent probe as described above is used for hydrogen sulfide detection.

[0014] As a preferred embodiment, the hydrogen sulfide detection is the detection of hydrogen sulfide in an aquatic environment system and / or the sensing detection of hydrogen sulfide content.

[0015] As a preferred embodiment, the hydrogen sulfide detection is a sensor-based detection of the hydrogen sulfide content in food.

[0016] As a preferred embodiment, the hydrogen sulfide content sensing detection is a combination of colorimetric fluorescence detection and visual qualitative detection.

[0017] A hydrogen sulfide detection test strip includes filter paper on which a hydrogen sulfide fluorescent probe as described above is attached.

[0018] The principle of fluorescence detection of hydrogen sulfide: The hydrogen sulfide fluorescent probe of this invention comprises a fluorophore (benzothiazole-chalcone conjugated structure) and a recognition / quenching group (thioacetamide-rhodamine fragment). Under normal conditions, the quenching group inhibits the excited-state electronic transition of the fluorophore through photoinduced electron transfer (PET) or intramolecular charge transfer (ICT) effects, therefore the hydrogen sulfide fluorescent probe itself is almost non-fluorescent; when hydrogen sulfide is added, the sulfur ions (HS-H2O) of hydrogen sulfide... - The fluorophore attacks the electrophilic center (carbonyl carbon) of the thioacetamide ring in the hydrogen sulfide fluorescent probe, initiating a thiolysis reaction that causes the thioacetamide ring to open, releasing a free fluorophore. Simultaneously, the previously quenched conjugated π-bond system regains its electron delocalization ability, the intramolecular conjugated system of the fluorophore is restored, and the electronic transition efficiency is significantly improved. When excited at a wavelength of 400 nm, the fluorophore emits strong fluorescence (usually green or yellow), and its fluorescence intensity is positively correlated with the concentration of H₂S, thus enabling quantitative detection.

[0019] The beneficial effects of this invention are as follows: the synthesis of the hydrogen sulfide fluorescent probe can be completed in one step, the raw materials are simple, inexpensive and readily available, the post-processing is simple, the hydrogen sulfide fluorescent probe responds only to H2S and is not interfered with by other thiols (such as glutathione and cysteine) in the body, it has high selectivity, good detection specificity for H2S, low detection limit, and high linearity between fluorescence intensity and H2S concentration, which can realize rapid and sensitive qualitative or quantitative detection of H2S in solution and solid, and has broad application prospects. Attached Figure Description

[0020] Figure 1 The hydrogen sulfide fluorescent probe of this invention (concentration 1×10⁻⁶) -5 Selectivity results of different analytes in EtOH / H2O (1 / 9, v / v, pH = 7.4) system (mol / L); Figure 2 The hydrogen sulfide fluorescent probe of this invention (concentration 1×10⁻⁶) -5 Fluorescence spectrum response of H2S at different concentrations in EtOH / H2O (1 / 9, v / v, pH = 7.4) system (mol / L); Figure 3 The hydrogen sulfide fluorescent probe of this invention (concentration 1×10⁻⁶) -5 The graph shows the relationship between fluorescence intensity at 650 nm and H2S concentration in the EtOH / H2O (1 / 9, v / v, pH = 7.4) system (mol / L). Figure 4 The hydrogen sulfide fluorescent probe of this invention (concentration 1×10⁻⁶) -5 UV-Vis spectral response of H2S at different concentrations in the EtOH / H2O (1 / 9, v / v, pH = 7.4) system (mol / L); Figure 5 The image shows the observation results of the hydrogen sulfide fluorescent probe of the present invention under sunlight and 365nm ultraviolet light conditions after the addition of hydrogen sulfide. Figure 6 This is a graph showing the response of the fluorescent probe test strip of the present invention to H2S. Figure 7 The image shows the detection results of H2S in pork, fish, chicken and fresh shrimp using the fluorescent probe test strip of this invention. Detailed Implementation

[0021] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0022] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention. Example 1

[0023] Preparation of hydrogen sulfide fluorescent probe Accurately weigh 291.06 mg (1 mmol) of ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazolium-5-carboxylate and 210.34 mg (1.1 mmol) of carboxymethyl rotannin, dissolve them in 20 mL of glacial acetic acid, and heat under reflux at 130 °C for 6 h. Monitor the reaction progress using a TLC plate during the reaction. After the reaction is complete, cool the system to room temperature. A precipitate will form after cooling. Filter the precipitate and remove the solid portion. Wash the solid portion with ethanol 2-3 times and dry it to obtain a yellow solid product with a yield of 60.39%, which is the hydrogen sulfide fluorescent probe. Example 2

[0024] Preparation of hydrogen sulfide fluorescent probe Accurately weigh 291.06 mg (1 mmol) of ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazol-5-carboxylate and 229.46 mg (1.2 mmol) of carboxymethyl rotannin, dissolve them in 20 mL of glacial acetic acid, and heat under reflux at 120 °C for 5 h. Monitor the reaction progress using a TLC plate during the reaction. After the reaction is complete, cool the system to room temperature. A precipitate will form after cooling. Filter the precipitate and remove the solid portion. Wash the solid portion with ethanol 2-3 times and dry it to obtain a yellow solid product with a yield of 60.39%, which is the hydrogen sulfide fluorescent probe. Example 3

[0025] Preparation of hydrogen sulfide fluorescent probe Accurately weigh 291.06 mg (1 mmol) of ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazolium-5-carboxylate and 248.58 mg (1.3 mmol) of carboxymethyl rotannin, dissolve them in 20 mL of glacial acetic acid, and heat under reflux at 125 °C for 5.5 h. Monitor the reaction progress using a TLC plate during the reaction. After the reaction is complete, cool the system to room temperature. A precipitate will form after cooling. Filter the precipitate and remove the solid portion. Wash the solid portion with ethanol 2-3 times and dry it to obtain a yellow solid product with a yield of 60.39%, which is the hydrogen sulfide fluorescent probe.

[0026] Test Example 1 Fluorescence selectivity experiment of hydrogen sulfide fluorescent probe for different analytes The hydrogen sulfide fluorescent probe prepared in Example 1 was dissolved in ethanol to prepare a solution with a concentration of 1×10⁻⁶. -4 The mol / L stock solution was set aside for later use. Then, the stock solution was diluted with deionized water to prepare a solution with a concentration of 1×10⁻⁶. -5 A probe solution of mol / L (ethanol to water volume ratio 9:1, pH=7.4) was added with a concentration of 5×10⁻⁶. -5 A test solution was obtained by preparing an analyte solution at a concentration of mol / L; wherein the analytes include GSH (glutathione), Cys (cysteine), Hcy (homocysteine), Gly (glycine), Met (methionine / methionine), Arg (arginine), Lys (lysine), Leu (leucine), Pro (proline), Trp (tryptophan), Serine (serine), Threonine (threonine), Phe (phenylalanine), Tyr (phenylalanine), Val (valine), and ClO. - (hypochlorite ion), H2O2 (hydrogen peroxide), Ag + (Silver ions), K + (Potassium ions), Na + (Sodium ion), Li + (Lithium ion), Pb 2+ (Lead ions), Mg 2+ (Magnesium ions), Ca 2+ (Calcium ions), Ba 2+ (Barium ions), Hg 2+ (mercury ions), Ni 2+ (Nitrile ions), Sr 2+ (Barium ions), Al 3+ (Aluminum ions), Fe 3+ (Iron ions), Cr 3+ (complex ion), Bi 3+ (bismuth ion), Cu 2+ (Copper ions) and H2S (hydrogen sulfide).

[0027] The probe solution and test solution were tested using a fluorescence spectrophotometer (excitation wavelength 400 nm), and the results are as follows: Figure 1 As shown.

[0028] Depend on Figure 1 It was found that the probe solution exhibited weak green fluorescence under 400 nm ultraviolet light excitation. However, after the addition of H2S, it emitted strong red fluorescence at 645 nm. The addition of other analytes did not cause significant changes in the fluorescence spectrum.

[0029] Test Example 2 Experiments on the fluorescence characteristics of hydrogen sulfide fluorescent probes for different concentrations of hydrogen sulfide. The hydrogen sulfide fluorescent probe prepared in Example 1 was dissolved in ethanol to prepare a solution with a concentration of 1×10⁻⁶. -4 The mol / L stock solution was set aside for later use. Then, the stock solution was diluted with deionized water to prepare a solution with a concentration of 1×10⁻⁶. -5 A probe solution of mol / L (ethanol to water volume ratio 9:1, pH=7.4) was prepared by adding hydrogen sulfide solutions with concentrations ranging from 0 to 50 μM. The test solutions were then tested using a fluorescence spectrophotometer and a UV-Vis spectrophotometer, respectively. The results are shown below. Figure 2 , Figure 3 and Figure 4 As shown.

[0030] Depend on Figure 2 , Figure 3 and Figure 4 It can be seen that at 650 nm, the fluorescence intensity change of the hydrogen sulfide fluorescent probe has a good linear relationship with the H2S concentration, meaning that the hydrogen sulfide fluorescent probe can achieve quantitative detection of hydrogen sulfide through fluorescence intensity, and the detection limit is 2.29 × 10⁻⁶. -8 M. Furthermore, in the UV-Vis spectrum, at 230 nm, the absorbance change of the hydrogen sulfide fluorescent probe showed a good linear relationship with the H2S concentration.

[0031] Test Example 3 Visual experiment of hydrogen sulfide fluorescent probe on hydrogen sulfide The hydrogen sulfide fluorescent probe prepared in Example 1 was dissolved in ethanol to prepare a solution with a concentration of 1×10⁻⁶. -4 The mol / L stock solution was set aside for later use. Then, the stock solution was diluted with deionized water to prepare a solution with a concentration of 1×10⁻⁶. -5 A probe solution of mol / L (ethanol to water volume ratio 9:1, pH=7.4) was prepared by gradually adding 0~5×10 mol / L of water. -5 A mol / L hydrogen sulfide solution was observed under sunlight and under a 365nm ultraviolet lamp, respectively. The results are as follows: Figure 5 As shown.

[0032] Depend on Figure 5 It can be seen that under a 365nm ultraviolet lamp, the fluorescence color of the probe solution changed from dark green to red after the addition of hydrogen sulfide solution; under sunlight, the color of the probe solution changed from dark green to dark red after the addition of hydrogen sulfide solution.

[0033] Test Example 4 Visual test of fluorescent probe test paper on hydrogen sulfide The hydrogen sulfide fluorescent probe prepared in Example 1 was dissolved in ethanol to prepare a solution with a concentration of 1×10⁻⁶. -4 The mol / L stock solution was set aside for later use. Then, filter paper was placed in the probe solution. After the solution evaporated, fluorescent probe test paper was obtained. Different concentrations of hydrogen sulfide solution (0 μM, 5 μM, 10 μM, 20 μM, 30 μM, 40 μM, and 50 μM) were gradually added. Fluorescent probe test paper without added hydrogen sulfide solution and fluorescent probe test paper with added hydrogen sulfide solution were observed under sunlight and under a 365 nm UV lamp. The results are as follows. Figure 6 As shown.

[0034] Depend on Figure 6 It was observed that the fluorescent probe paper without hydrogen sulfide solution was light yellow-green under sunlight and light yellow under a 365 nm ultraviolet lamp. However, the fluorescent probe paper with added hydrogen sulfide solution gradually changed from light yellow-green to dark red under sunlight, and from light yellow to red under a 365 nm ultraviolet lamp. These experiments demonstrate that the fluorescent probe paper prepared from hydrogen sulfide fluorescent probes can detect H2S through changes in fluorescence color and sunlight color.

[0035] Test Example 5 Detection experiments of fluorescent probe test strips on food The fluorescent probe test strips prepared in Test Example 4 were placed in sealed spaces along with pork, fish, chicken, and fresh shrimp, and observed under sunlight and a 365nm ultraviolet lamp, respectively. The results are as follows: Figure 7 As shown.

[0036] Depend on Figure 7 As the food was left for an extended period, it began to rot, releasing H2S gas. Under sunlight, the corresponding fluorescent probe changed color from dark green to dark red. Under a 365nm ultraviolet lamp, the fluorescence color of the corresponding fluorescent probe changed from dark green to dark red. In conclusion, hydrogen sulfide fluorescent probes can be used for the visual detection of H2S in food.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A hydrogen sulfide fluorescent probe, characterized in that, Its structural formula is shown in equation (I): （I）。 2. A method for preparing the hydrogen sulfide fluorescent probe as described in claim 1, characterized in that, Includes the following steps: Ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazol-5-carboxylic acid was dissolved in glacial acetic acid and subjected to a reflux reaction. After the reaction was complete, the mixture was cooled to room temperature, filtered, washed and dried to obtain a hydrogen sulfide fluorescent probe.

3. The method for preparing the hydrogen sulfide fluorescent probe according to claim 2, characterized in that, The molar ratio of ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid to carboxymethyl razotanine is 1:1.1-1.

3.

4. The method for preparing the hydrogen sulfide fluorescent probe according to claim 2, characterized in that, The heating temperature in the reflux process is 120-130℃, and the reaction time is 5-6 hours.

5. The method for preparing the hydrogen sulfide fluorescent probe according to claim 2, characterized in that, During the washing process, the filtered solid is washed with ethanol, and the washing is performed at least twice.

6. A hydrogen sulfide fluorescent probe as described in claim 1 for the detection of hydrogen sulfide.

7. The application according to claim 6, characterized in that, The hydrogen sulfide detection refers to the detection of hydrogen sulfide in the aquatic environment system and / or the sensing detection of hydrogen sulfide content.

8. The application according to claim 6, characterized in that, The hydrogen sulfide detection refers to the sensor detection of hydrogen sulfide content in food.

9. The application according to claim 7 or 8, characterized in that, The hydrogen sulfide content sensing detection is performed using colorimetric fluorescence detection and visual qualitative detection.

10. A hydrogen sulfide detection test strip, characterized in that, Includes filter paper on which the hydrogen sulfide fluorescent probe as described in claim 1 is attached.

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