Sulfur-containing pollutant visual probe as well as preparation method and application thereof

Abstract

The invention discloses a sulfur-containing pollutant visual probe and a preparation method and application thereof, and the sulfur-containing pollutant visual probe comprises a compound shown in a formula I. The compound shown in the formula I of the visual probe can be used for simultaneously detecting various sulfur-containing pollutants; and whether a thiophenol compound pollutant system contains sulfur dioxide or derivatives of sulfur dioxide or not shows different fluorescence or color differences.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental detection, and in particular to a sulfur-containing pollutant visualization probe, a preparation method thereof, and an application thereof. Background Art

[0002] With the development of my country's industry, the importance of effectively reducing environmental pollution and preventing sudden environmental incidents has become increasingly prominent. Benzothiophenol (PhSH), as an important intermediate, is widely used in the preparation of pharmaceuticals and chemical products. However, PhSH is irritating and highly toxic. When industrial wastewater containing PhSH enters human life, it can cause irreversible harm to the public. Furthermore, in industrial wastewater from the petrochemical and fine chemical industries, sulfur-containing pollutants, most notably sulfur dioxide, often coexist with PhSH. However, most current visualization probes can only respond to a single pollutant. Detecting two or more pollutants requires the use of multiple probes or a combination of multiple methods, which can hinder rapid detection. Therefore, developing simple and rapid on-site detection methods to specifically distinguish PhSH from other pollutants in industrial wastewater in real time can simplify the detection process when multiple pollutants coexist, providing a powerful technical support for environmental safety monitoring. Summary of the Invention

[0003] The present invention aims to solve at least one of the above-mentioned technical problems in the prior art. To this end, the present invention aims to provide a sulfur-containing pollutant visualization probe and its preparation method and application.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a sulfur-containing pollutant visualization probe comprising a compound of formula I:

[0006]

[0007] Wherein, X is a halogen;

[0008] R1 is selected from H, halogen, carbonyl, amide, carboxyl, nitro, cyano, aldehyde, amino, sulfonyl, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C6-C 10 Aryl, C5~C 10 Heteroaryl; the alkyl, alkenyl, alkynyl, aryl, heteroaryl are optionally unsubstituted or substituted by one or more R 11 replace;

[0009] Or R1 and the atoms connected to it form C6~C 10 aryl;

[0010] R 11 Selected from halogen, C1-C6 alkyl;

[0011] R2 is selected from C6~C 10 Aryl, C5~C 10 Heteroaryl; said optionally unsubstituted, or substituted by one or more R 11 replace;

[0012] R3 is selected from C1 to C6 alkyl.

[0013] In some embodiments of the present invention, the halogen includes fluorine, chlorine, bromine, and iodine.

[0014] In some embodiments of the present invention, the C1-C6 alkyl group includes methyl, ethyl, propyl, isopropyl, butyl, pentyl, and hexyl.

[0015] In some embodiments of the present invention, the C6~C 10 Aryl groups include phenyl and naphthyl.

[0016] In some embodiments of the present invention, the compound of formula I is selected from the following compounds:

[0017]

[0018] The second aspect of the present invention provides a method for preparing the sulfur-containing pollutant visualization probe, comprising the following steps:

[0019] The compound of formula II and the compound of formula III are reacted to prepare the compound of formula I;

[0020]

[0021] Wherein, X, R1, R2, and R3 are as defined above.

[0022] In some embodiments of the present invention, the reaction is carried out in an organic solvent; the organic solvent comprises at least one of ethanol, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, and N-methylpyrrolidone.

[0023] In some embodiments of the present invention, the reaction temperature is 40 to 120° C.; and the reaction time is 2 to 24 hours.

[0024] A third aspect of the present invention provides a method for detecting sulfur-containing pollutants, comprising the following steps:

[0025] The sulfur-containing pollutant visualization probe is added to the sulfur-containing pollutant to perform spectrum detection.

[0026] In the present invention, when the sulfur-containing pollutant is a thiophenol compound, the thiophenol compound can nucleophilically attack the phenyl ether group of the compound of formula I, causing the phenyl ether to undergo thiolysis, and the dinitrophenyl ether is replaced and converted into a phenolic hydroxyl group. Further, through a removal reaction, the compound of formula I removes the strong electron-withdrawing group 2,4-dinitrobenzene, freeing the phenolic hydroxyl group of the fluorophore, thereby causing the probe to produce color or emit fluorescence, thereby producing a visual color difference.

[0027] When sulfur-containing pollutants include sulfur dioxide or its derivatives and thiophenol compounds, traditional detection methods typically require multiple probes or a combination of multiple methods, which can be inconvenient for rapid detection. However, when using the compounds of Formula I of the present invention for detection, sulfur dioxide or its derivatives can attack unsaturated C=C bonds through nucleophilic addition, changing the distribution of electron clouds in hemicyanine molecules and interrupting their macroconjugated structure, thereby changing the color and fluorescence of the molecular probe, thereby achieving simultaneous detection of sulfur dioxide or its derivatives and thiophenol compounds. The detection mechanism of the compounds of Formula I is as follows:

[0028]

[0029] In some embodiments of the present invention, the detection is carried out in a mixed solvent of ethanol and water; the mixing volume ratio of ethanol and water is (4-8): (2-6), such as (5-7): (3-5), 6:4, etc.

[0030] In some embodiments of the present invention, the spectral detection includes ultraviolet-visible spectral detection and / or fluorescence spectral detection.

[0031] In some embodiments of the present invention, the ultraviolet-visible light spectrum detection includes detecting the light absorption intensity at a wavelength of 300 to 580 nm; such as a wavelength of 300 to 340 nm, a wavelength of 320 nm, a wavelength of 530 to 570 nm, a wavelength of 550 nm, and a wavelength of 560 nm.

[0032] In some embodiments of the present invention, the fluorescence spectrum detection includes detecting the fluorescence intensity at a wavelength of 400 to 600 nm under excitation at an excitation wavelength of 380 to 420 nm; such as at a wavelength of 410 to 450 nm, a wavelength of 430 nm, a wavelength of 450 nm, a wavelength of 550 to 590 nm, and a wavelength of 570 nm.

[0033] In some embodiments of the present invention, the sulfur-containing pollutants include sulfur-containing pollutants in at least one of water, soil, or biological systems.

[0034] In some embodiments of the present invention, the mass concentration of the sulfur-containing pollutant is 1.0 μM to 100.0 μM; such as 1.0 μM to 80.0 μM, 1.0 μM to 50.0 μM.

[0035] In some embodiments of the present invention, the sulfur-containing pollutants include sulfur dioxide or its derivatives, and / or benzenethiophenol compounds.

[0036] In some embodiments of the present invention, the sulfur dioxide or its derivatives include at least one of sulfur dioxide, sodium sulfate, and sodium bisulfate.

[0037] In some embodiments of the present invention, the thiophenol compound includes at least one of thiophenol, p-aminothiophenol, and p-nitrothiophenol.

[0038] In some embodiments of the present invention, the ultraviolet-visible light spectrum has an absorption peak at a wavelength of 530 to 570 nm; and / or, when excited at an excitation wavelength of 380 to 420 nm, the fluorescence spectrum has an absorption peak at a wavelength of 550 to 590 nm, the sulfur-containing pollutant is a thiophenol compound.

[0039] In some embodiments of the present invention, the absorption peak of the ultraviolet-visible light spectrum disappears at a wavelength of 530-570 nm and has an absorption peak at a wavelength of 300-340 nm; and / or, when excited at an excitation wavelength of 380-420 nm, the fluorescence spectrum has an absorption peak at a wavelength of 460 nm, and the sulfur-containing pollutant is at least one of sulfur dioxide, sodium sulfate, sodium bisulfate, and thiophenol compounds.

[0040] The beneficial effects of the present invention are:

[0041] The visualization probe compound of formula I of the present invention can simultaneously detect multiple sulfur-containing pollutants, and exhibits different fluorescence or color differences depending on whether the benzenethiol compound-containing pollutant system contains sulfur dioxide or its derivatives.

[0042] The fluorescent probe compound of formula I of the present invention can perform qualitative and quantitative detection on thiophenol compounds.

[0043] The probe preparation method of the present invention is simple, the raw material sources are diversified, and it is easy to produce and apply on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the fluorescent probe P-1 in Example 1 of the present invention.

[0045] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the fluorescent probe P-2 in Example 2 of the present invention.

[0046] Figure 3 (a) UV-visible absorption spectrum and (b) fluorescence emission spectrum of the ethanol / water solution of the fluorescent probe P-1 in Example 3 of the present invention before and after the addition of thiophenol.

[0047] Figure 4 The ethanol / water solution of the fluorescent probe P-1 in Example 3 of the present invention has SO3 2- (a) UV-visible absorption spectra and (b) fluorescence emission spectra before and after the addition of thiophenol in the presence of .

[0048] Figure 5 (a) UV-absorption spectra of the ethanol / water solution of the fluorescent probe P-1 in Example 3 of the present invention and different sulfur-containing pollutants, and (b) selectivity analysis histogram of the probe P-1.

[0049] Figure 6 (a) UV-visible absorption spectrum and (b) fluorescence emission spectrum of the ethanol / water solution of the fluorescent probe P-2 in Example 4 of the present invention before and after the addition of thiophenol.

[0050] Figure 7 The ethanol / water solution of the fluorescent probe P-2 in Example 4 of the present invention has SO3 2- (a) UV-visible absorption spectra and (b) fluorescence emission spectra before and after the addition of thiophenol in the presence of .

[0051] Figure 8 (a) UV-visible absorption spectrum and (b) fluorescence emission spectrum of the ethanol / water solution of the fluorescent probe P-2 in Example 4 of the present invention after adding different concentrations of thiophenol. DETAILED DESCRIPTION

[0052] The present invention is further described in detail below using specific examples. Unless otherwise specified, the raw materials, reagents, and apparatus used in the examples and comparative examples are available from conventional commercial sources or by conventional methods. Unless otherwise specified, all experimental or testing methods are conventional in the art.

[0053] Example 1

[0054] This example prepares a sulfur-containing pollutant visualization probe, and the specific process is as follows:

[0055] S1: 4.9 mmol (600 mg) of p-hydroxybenzaldehyde, 6 mmol (828 mg) of potassium carbonate, and 5 mmol (1012 mg) of 1-chloro-2,4-dinitrobenzene were weighed and dissolved in 3 mL of N,N-dimethylformamide. The mixture was heated at 50°C for 5 h. After the reaction, it was cooled to room temperature and the residue was removed by filtration to obtain an orange-yellow filtrate. The organic solvent was removed to obtain 1.1 g of an orange-yellow solid, which was intermediate A, with a yield of 78%.

[0056]

[0057] S2: Weigh 5 mmol (760.75 mg) of 4-hydrazinobenzoic acid and 5 mmol (430.65 mg) of 3-methylbutan-2-one and dissolve them in 10 mL of acetic acid. Under nitrogen protection, react in an oil bath at 100°C for about 13 h. After the reaction, cool to room temperature and add 45.5 mL of ether dropwise to the reaction solution to produce a small amount of precipitate. Adjust the pH to neutral with saturated sodium carbonate solution, extract with dichloromethane, and remove the organic solvent to obtain 0.41 g of an orange-yellow solid, which is intermediate B, with a yield of 40%.

[0058]

[0059] S3: Weigh 2 mmol (406 mg) of intermediate B and 3 mmol of iodomethane and dissolve them in 10 mL of anhydrous acetonitrile. Under nitrogen protection, heat and stir in an oil bath at 82°C for 24 h. After the reaction, cool to room temperature and add 20 mL of ethyl acetate to adjust the polarity and precipitate the solute. Filter and wash; dry in a vacuum drying oven at 45°C to obtain 0.51 g of orange-gray powder, which is intermediate C, with a yield of 74%.

[0060]

[0061] S4: Weigh 1 mmol (288 mg) of intermediate A and 1 mmol (345 mg) of intermediate C and dissolve them in 8 mL of EtOH. Under nitrogen protection, heat and stir in an oil bath at 79°C for 12 h. After the reaction, cool to room temperature and remove EtOH. Add an appropriate amount of ethyl acetate until no more precipitates are formed. Filter and wash, and vacuum dry to obtain 0.4065 g of an orange solid, which is the target fluorescent probe P-1, with a yield of 86%.

[0062]

[0063] The nuclear magnetic resonance hydrogen spectrum of the fluorescent probe P-1 is shown in Figure 1 shown.

[0064] Example 2

[0065] This example prepares a sulfur-containing pollutant visualization probe, and the specific process is as follows:

[0066] S1: 2 mmol (0.42 g) of 1,1,2-trimethyl-1H-benz[e]indole was weighed and dissolved in 10 mL of anhydrous acetonitrile. 3 mmol of iodomethane was then added, and the mixture was heated under reflux at 83°C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and 20 mL of ethyl acetate was added until no more precipitate was formed. The precipitate was washed by filtration, and the solvent was dried under vacuum to obtain 0.36 g of a gray-green solid, which was intermediate D, with a yield of 51.8%.

[0067]

[0068] S2: Weigh 1.2 mmol (0.3456 g) of intermediate A and 1 mmol (0.3530 g) of intermediate D, dissolve them in 8 mL of acetonitrile, and heat and stir at 79°C for 24 h under nitrogen protection; after the reaction is completed, cool to room temperature, remove the solvent, add ethyl acetate for washing, let it stand to separate, absorb the supernatant and filter to obtain a gray-green solid, which is the target fluorescent probe P-2.

[0069]

[0070] The nuclear magnetic resonance hydrogen spectrum of fluorescent probe P-2 is shown in Figure 2 shown.

[0071] Example 3

[0072] This example uses fluorescent probe P-1 to detect sulfur-containing pollutants. The specific process is as follows:

[0073] The fluorescent probe P-1 was prepared into a test solution with a concentration of 10 μmol / L using an ethanol-water mixture (v / v, 6 / 4). 3 mL of the above solution was placed in a cuvette and the UV-visible absorption and fluorescence emission spectra of P-1 in the ethanol-water solution were obtained using a UV-visible spectrophotometer and a fluorescence spectrophotometer. 30 μL of a 10 μmol / L solution was then added. -3 mol / L PhSH ethanol solution, and the UV-visible absorption and fluorescence spectra were measured again. The results before and after addition were as follows: Figure 3 As shown. Figure 3 As can be seen in (a), there is a clear absorption peak at 550nm, and the color of the solution changes from colorless to rose red after adding PhSH. In addition, the fluorescence also changes from none to light pink after adding PhSH. In the fluorescence spectrum, after adding PhSH, with an excitation wavelength of 400nm, a new peak can be seen at 570nm (as shown in Figure 2). Figure 3 (b)).

[0074] When one of the SO2 derivatives Na2SO3 and NaHSO3 exists in the solution (concentration is 10μmol / L), the UV-visible absorption and fluorescence emission spectra of the P-1 ethanol-water mixed solution after adding PhSH are as follows: Figure 4As shown in (a) and (b) above, in the presence of SO₂ derivatives, the addition of PhSH causes the UV-Vis absorption spectrum of the solution to disappear at 550nm, while a distinct absorption peak appears at 320nm. The solution changes from pink to colorless. In the fluorescence emission spectrum, when SO₂ derivatives are present, the addition of PhSH causes the solution to produce strong blue fluorescence, accompanied by a significant increase in the fluorescence peak at 430nm, which is significantly different from the fluorescence spectrum of the solution containing only PhSH.

[0075] In addition, referring to the aforementioned detection method, 3 μL of prepared 50 mM cysteine ​​(Cys), glutathione (GSH), p-aminothiophenol, p-methylthiophenol, p-nitrothiophenol, NaHSO₃, and 10 mM thiophenol were added to a 3 mL ethanol-water solution containing 10 μM fluorescent probe P-1. The responses of fluorescent probe P-1 to the various substances were measured.

[0076] The results showed that the P-1 molecule has a certain specificity for thiophenol ( Figure 5 ).

[0077] Example 4

[0078] This example uses fluorescent probe P-2 to detect sulfur-containing pollutants. The specific process is as follows:

[0079] The fluorescent probe P-2 was prepared into a test solution with a concentration of 10 μmol / L using an ethanol-water mixture (v / v, 6 / 4). 3 mL of the above solution was placed in a cuvette and the UV-visible absorption and fluorescence emission spectra of P-2 in the ethanol-water solution were obtained using a UV-visible spectrophotometer and a fluorescence spectrophotometer. 30 μL of a 10 μmol / L solution was then added. -3 mol / L PhSH ethanol solution, and the UV-visible absorption and fluorescence spectra were measured again. The results before and after addition were as follows: Figure 6 After adding PhSH, Figure 6 As can be seen in (a), in the UV-visible spectrum, a clear absorption peak appears at 560nm, and the color of the solution changes from colorless to rose red. In addition, the fluorescence of the molecular probe also changes from light pink to colorless after the addition of PhSH. The fluorescence emission spectrum shows that the peaks at 455nm and 600nm decrease significantly with the addition of PhSH ( Figure 6 (b)).

[0080] When one of the SO2 derivatives Na2SO3 and NaHSO3 exists in the solution (concentration is 10μmol / L), the UV-visible absorption and fluorescence emission spectra of the P-2 ethanol-water mixed solution after adding PhSH are as follows: Figure 7As shown in (a) and (b), in the presence of SO2 derivatives, the addition of PhSH causes the peak at 560nm in the solution's UV-Vis absorption spectrum to disappear, while a distinct absorption peak appears at 320nm, causing the solution to turn from pink to colorless. In the fluorescence emission spectrum, when SO2 derivatives are present, the P-2 solution produces blue fluorescence, with a new peak appearing at 450nm. The addition of PhSH causes a red shift in the solution spectrum to 460nm, accompanied by enhanced blue fluorescence. This is significantly different from the UV-Vis absorption and fluorescence spectra of solutions containing only PhSH and SO2 derivatives.

[0081] Example 5

[0082] This example uses fluorescent probe P-2 to perform quantitative analysis on sulfur-containing pollutants. The specific process is as follows:

[0083] Referring to the above detection method, 3 μL of prepared PhSH solutions of different concentrations were added to 3 mL of ethanol-water solution with a concentration of 10 μM fluorescent probe P-2. The molar ratios of PhSH to probe P-2 were 0, 0.1:1, 0.2:1, 0.5:1, 1:1, 2:1, and 5:1, respectively. The UV-visible absorption spectra ( Figure 8 As shown in (a), with the increase of PhSH concentration, the absorption peak at 550 nm gradually increases and then slows down; the fluorescence spectrum ( Figure 8 In (b), increasing PhSH concentration leads to a gradual decrease in the fluorescence intensity of P-2, with the peaks at 455 nm and 600 nm gradually decreasing before leveling off. The detection limit of the P-2 probe for PhSH is calculated to be as low as 1.5 μM.

[0084] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A sulfur pollutant visualization probe, characterized by: Includes compounds of formula I: Wherein, X is a halogen; R1 is selected from H, halogen, carbonyl, amide, carboxyl, nitro, cyano, aldehyde, amino, sulfonyl, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C6-C 10 Aryl, C5~C 10 Heteroaryl; the alkyl, alkenyl, alkynyl, aryl, heteroaryl are optionally unsubstituted or substituted by one or more R 11 replace; Or R1 and the atoms connected to it form C6~C 10 aryl; R 11 Selected from halogen, C1-C6 alkyl; R2 is selected from C6~C 10 Aryl, C5~C 10 Heteroaryl; said optionally unsubstituted, or substituted by one or more R 11 replace; R3 is selected from C1 to C6 alkyl.

2. The sulfur-containing pollutant visualization probe according to claim 1, characterized in that: The compound of formula I is selected from the following compounds:

3. A method for preparing the sulfur-containing pollutant visualization probe according to claim 1 or 2, characterized in that: The following steps are involved: The compound of formula II and the compound of formula III are reacted to prepare the compound of formula I; Wherein, X, R1, R2, and R3 are defined as described in claim 1 or 2.

4. A method for detecting sulfur-containing pollutants, characterized in that: The following steps are involved: Add the sulfur-containing pollutant visualization probe according to claim 1 or 2 to the sulfur-containing pollutant for spectral detection.

5. The method for detecting sulfur-containing pollutants according to claim 4, wherein: The detection is carried out in a mixed solvent of ethanol and water; preferably, the mixed volume ratio of ethanol to water is (4-8): (2-6).

6. The method for detecting sulfur-containing pollutants according to claim 4, wherein: The spectrum detection includes ultraviolet-visible spectrum detection and / or fluorescence spectrum detection.

7. The method for detecting sulfur-containing pollutants according to claim 6, wherein: The ultraviolet-visible light spectrum detection includes detecting the light absorption intensity at a wavelength of 300 to 580 nm; the fluorescence spectrum detection includes detecting the fluorescence intensity at a wavelength of 400 to 600 nm under excitation at an excitation wavelength of 380 to 420 nm.

8. The method for detecting sulfur-containing pollutants according to claim 4, wherein: The sulfur-containing pollutants include sulfur-containing pollutants in at least one of water, soil or biological systems.

9. The method for detecting sulfur-containing pollutants according to claim 8, wherein: The mass concentration of the sulfur-containing pollutant is 1.0 μM to 100.0 μM.

10. The method for detecting sulfur-containing pollutants according to claim 4, characterized in that: The sulfur-containing pollutants include sulfur dioxide or its derivatives, and / or benzenethiophenol compounds.

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