Fluorescent probe compound, preparation method and application of fluorescent probe compound in detection of sulfite

Abstract

The invention particularly relates to a fluorescent probe compound, a preparation method and application of the fluorescent probe compound to detection of sulfite. The fluorescent probe TM2 capable of being used for detecting HSO3 <-> is designed and synthesized by taking acenaphthene imidazole as a parent body, and the structure of the fluorescent probe TM2 is shown in the specification. The compound can be used as a ratio type fluorescent probe for measuring HSO3 <->, and an analysis method established based on TM2 has the characteristics of quick response, good selectivity, high sensitivity, mild conditions and the like, and can be widely used for measuring the content of HSO3 <-> in a liquid environment.

Description

Technical Field

[0001] This invention belongs to the field of sulfite fluorescent probe technology, specifically relating to a fluorescent probe compound, its preparation method, and its application in detecting sulfite ions. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Currently, the main methods for detecting sulfite include spectrophotometry, fluorescence spectrophotometry, chemiluminescence, phosphorescence, chromatography, electrochemical analysis, and ion-selective electrode methods. However, some of these methods have poor selectivity, some require complex sample pretreatment, and some lack sufficient sensitivity to meet the sample detection requirements. Therefore, developing new analytical methods for detecting sulfite with good selectivity, convenience, and high sensitivity is of great significance. Summary of the Invention

[0004] This invention designs and synthesizes a reagent for detecting HSO3 using acenaphthene-imidazole as the parent compound. - The fluorescent probe TM2 combines the acenaphthene-imidazole parent compound with a hemicyanine dye to construct a fluorescence sensing platform. Fluorescence response is achieved through bisulfite interaction, cleaving or linking the conjugated system, exhibiting a significant advantage of short response time. Therefore, the TM2 molecule can be used as a probe for measuring HSO3. - A ratiometric fluorescent probe. The analytical method based on TM2 features rapid response, good selectivity, high sensitivity, and mild conditions, and can be widely used for HSO3 in aqueous solutions. - Content determination.

[0005] Based on the above-mentioned technical effects, the present invention provides the following technical solution: In a first aspect, the present invention provides a fluorescent probe compound, the structure of which is shown in Formula I, or is a pharmaceutically acceptable salt or ester or solvate, tautomer, meso compound, racemic compound, stereoisomer, metabolite or prodrug of the compound shown in Formula I: Formula I is as follows: Formula I.

[0006] In the first aspect mentioned above, the fluorescent probe compound with the structure shown in Formula I is named fluorescent probe TM2. In this application, "fluorescent probe TM2" or "TM2" refers to the structure shown in Formula I.

[0007] In addition, according to the common understanding in the art, the pharmaceutically acceptable salt includes inorganic or organic salts of compounds represented by Formula I, wherein the inorganic salt includes salts formed with inorganic acids, such as hydrochloric acid, sulfuric acid, nitric acid, or hydrobromic acid, and the organic salt includes salts formed with organic acids, such as methanesulfonic acid, toluenesulfonic acid, or trifluoroacetic acid.

[0008] In a second aspect, the present invention provides a method for preparing the fluorescent probe compound described in the first aspect, comprising the following steps: (1) Dissolve acenaphthene, terephthalaldehyde and ammonium acetate in an organic reagent to obtain a solution. Heat the solution in a water bath to 90~98℃ and react for 1.5~3h. After the solution changes color, continue the reaction for 1~3h. After the reaction is completed, filter and retain the solid part to obtain intermediate TM1. (2) Dissolve intermediate TM1, 1,1,2-trimethyl-3-(4-butyl nitrate)-1H-benzo[E]indole inner salt and piperidine in an alcohol solvent, heat to 75~85℃ and react. After the solution color turns dark red, continue the reaction for 20~28h. After the reaction is completed, remove the solvent to obtain crude TM2.

[0009] The reaction route of the above preparation method is as follows: The above step (1) has the following preferred technical solution: The organic reagent is a low-carbon chain alkyl-substituted benzene, preferably toluene, xylene, or ethylbenzene. In one embodiment verified by the present invention, the organic reagent is toluene.

[0010] The dosage of acenaphthene, terephthalaldehyde, and ammonium acetate should be sufficient to allow them to react in a molar ratio of 1:3:2. Those skilled in the art may adjust the actual dosage of the raw materials based on factors such as purity, solubility, reaction rate, and characteristics of the reaction apparatus; this is also a foreseeable approach in this application. In some feasible embodiments verified by this invention, the addition ratio of acenaphthene, terephthalaldehyde, ammonium acetate, and toluene is 0.1~0.2g:0.3~0.4g:1~1.5g:12~20mL.

[0011] After the reaction is complete, the solid portion can be separated by filtration. The separated solid portion also needs to be washed, for example, by using the solvent of the reaction system, sodium bicarbonate solution, and water in sequence. Those skilled in the art can increase the number of washing times as needed, such as 1 to 5 times.

[0012] The above step (2) has the following preferred technical solution: The alcohol solvent is anhydrous, low-carbon alcohol solvent, such as methanol, ethanol, propanol, etc., and more preferably anhydrous ethanol. The amount of intermediate TM1, 1,1,2-trimethyl-3-(4-nitrate butyl)-1H-benzo[E]indole inner salt and piperidine should be sufficient to allow the above raw materials to react in a molar ratio of 1:1:1. Adjusting the dosage ratio is also a foreseeable approach in the art. In some feasible embodiments verified by this invention, the feeding ratio of intermediate TM1, 1,1,2-trimethyl-3-(4-nitrate butyl)-1H-benzo[E]indole inner salt, piperidine and anhydrous ethanol is 0.15~0.25g:0.2~0.3g:40~70μL:30~50mL.

[0013] After the reaction is complete, the solvent can be removed by evaporation, vacuum distillation, or other methods to obtain crude TM2. In a preferred embodiment, the crude TM2 is further purified. One feasible purification method is liquid-liquid extraction, in which the crude TM2 is dissolved in an organic reagent, then extracted with water, and the organic phase is retained while the solvent is evaporated to obtain TM2 solid powder.

[0014] In a third aspect, the present invention provides a composition comprising an active dose of the fluorescent probe compound described in the first aspect.

[0015] As generally understood, the "active dose" refers to the concentration at which the fluorescent probe compound can achieve the detection effect, which is something that a person skilled in the art can reasonably calculate based on the intended use.

[0016] In addition to the active dose of the fluorescent probe compound, the above composition also includes other active or auxiliary components; such auxiliary components include protective agents, carriers, solubilizers, antioxidants, stabilizers, pH adjusters, etc.

[0017] In a fourth aspect, the present invention provides the application of the fluorescent probe compound described in the first aspect and the composition described in the third aspect in the detection of sulfite.

[0018] In a fifth aspect, the present invention provides a method for detecting sulfite, comprising using the fluorescent probe compound described in the first aspect and the composition described in the third aspect for detection.

[0019] In one embodiment verified by the present invention, the detection method is an ultraviolet spectroscopy detection method, and the steps of the detection method are as follows: The fluorescent probe compound described in the first aspect is added to the test solution, and the absorption peak intensity at 366 nm is detected; if the absorption peak intensity increases, it indicates that sulfite ions are present in the test environment.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. The fluorescent probe TM2 provided by this invention combines acenaphthene imidazole parent compound with hemicyanine dye to construct a fluorescent sensing platform. It achieves fluorescence response by cleaving or linking conjugated systems through bisulfite action, and has the outstanding advantage of short response time. It has important application value for detecting sulfites in the water environment.

[0021] 2. The preparation methods of the fluorescent probes TM1 and TM2 provided by this invention have the advantages of inexpensive raw materials, mild synthesis process, easy purification and high yield, and are worthy of being put into research. They also have good selectivity and high sensitivity. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 The mass spectrum of TM1 described in Example 1; Figure 2 The ultraviolet-visible spectrum of TM1 described in Example 1; Figure 3 The infrared spectrum of TM1 described in Example 1; Figure 4 The mass spectrum of TM2 described in Example 1; Figure 5 The ultraviolet-visible spectrum of TM2 described in Example 1; Figure 6 The infrared spectrum of TM2 described in Example 1; Figure 7 The TM2 (30 μL) described in Example 4 was used to treat different volumes of HSO3. - Changes in the ultraviolet spectrum. Detailed Implementation

[0024] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0027] Example 1 This embodiment provides the preparation method and structural characterization results of the fluorescent probe TM2: The synthesis route for TM2 is as follows: Step (1) is as follows: Dissolve 0.145 g of acenaphthene, 0.322 g of terephthalaldehyde, and 1.230 g of ammonium acetate in 15 ml of toluene, and add the solution to a 100 ml three-necked flask. Stir the mixture in a 95°C water bath for 2 hours at 400–600 rpm. The solution color changes from yellow to a light yellowish-brown. After the reaction is complete, cool the solution, filter it, and wash it three times successively with toluene, 10% sodium bicarbonate, and deionized water to obtain TM1.

[0028] Step (2) is as follows: 0.21904 g (0.74 mmol) of TM1 was placed in a 100 mL three-necked flask. 0.2609 g (0.74 mmol) of 1,1,2-trimethyl-3-(4-butyl nitrate)-1H-benzo[E]indole inner salt was added to 40 mL of anhydrous ethanol. 61 μl of piperidine (0.74 mmol) was accurately pipetted into a round-bottom flask using a 100 μl pipette. The mixture was stirred until dissolved, and the solution turned yellow. The solution was heated to 80 °C and refluxed, changing from a yellow liquid to a deep red liquid. Reflux was continued for 24 h. The solvent was evaporated to dryness to obtain a reddish-black solid. Separation and purification: The crude product was dissolved in an appropriate amount of CH2Cl2, extracted three times with deionized water, and the organic phase was collected. The CH2Cl2 was evaporated to dryness to obtain a reddish-black powder.

[0029] Structural characterization I. TM1 1. Mass spectrometry structural characterization Its mass spectrometry results are as follows Figure 1 As shown, distinct peaks can be observed, such as m / z 297.3 and 318.5. Based on mass spectrometry analysis, the molecular weight of the obtained compound is equal to the calculated value, and its chemical formula is C. 20 H 12 N2O has the same molecular weight as the structure shown in TM1 above.

[0030] 2. Ultraviolet-Visible Spectrum Prepare a solution with a concentration of 1×10 using an ethanol:water solution (v:v, 1:1). -5 A mol / L TM1 solution. The UV spectrum of TM1 at room temperature is as follows. Figure 2 As shown. From Figure 2The study shows a steep absorption peak around 266 nm, leading to a decrease in light intensity, indicating strong absorption in this wavelength range. A distinct absorption band is also present at 362 nm, suggesting electronic transitions at the ligand center. The peak at 266 nm is the π→π* absorption peak of the benzene ring, while the peak at 362 nm is the π→π* absorption peak of the fully conjugated system. Due to the participation of the aldehyde group (-C=O) in conjugation, the delocalization range of π electrons is further expanded, resulting in lower transition energies and longer absorption wavelengths.

[0031] 3. Infrared spectrum like Figure 3 As shown, the infrared spectral data of TM1 are as follows: IR (KBr, cm⁻¹) -1 ):3425.68(m),1697.98(s),1633.41(s),1604.85(s),1557.29(s),1404.89(m),130 3.53(s),1208.55(s),1168.82(s),1016.33(s),820.59(s),772.18(s),654.58(m). The infrared spectrum is at 3425.68 cm⁻¹ -1 The moderately strong absorption peak observed at 1697.98 cm⁻¹ is attributed to the stretching vibration of the NH bond in the acenaphthene-imidazole ring. Intramolecular conjugation leads to an increase in the dipole moment of the NH bond, while intramolecular hydrogen bonding causes peak broadening. -1 A strong, sharp absorption peak is observed at this point, corresponding to the C=O stretching vibration of the aldehyde group. Because the aldehyde group forms a π-π conjugated system with the benzene ring, the electron cloud density of the C=O bond decreases, the bond force constant decreases, and the absorption peak red-shifts compared to the free aldehyde group's C=O vibration peak (approximately 1720 cm⁻¹). -1 ), shifting towards lower wavenumbers to 1700 cm -1 The following are typical spectral characteristics of aldehyde group conjugated with aromatic ring. At 1633.41 cm⁻¹ -1 1604.85 cm -1 1557.29 cm -1 The series of strong absorption peaks at 1404.89 cm⁻¹ originate from the C=C skeletal vibrations of the acenaphthene-imidazole ring and the benzene ring. The large π-conjugated system formed by the acenaphthene-imidazole ring and the benzene ring leads to the splitting of the C=C vibrational modes, and the coupling between these modes significantly enhances the absorption intensity, reflecting the structural characteristics of an aromatic conjugated molecular system. -1 The strong absorption peak at 1303.53 cm⁻¹ is due to the vibrational coupling between the CN stretching vibration of the acenaphthene-imidazole ring and the in-plane bending vibration of the CH group of the benzene ring. -1 The strong absorption peak corresponds to the in-plane bending vibration of the aromatic ring CH; at 820.59 cm⁻¹ -1The absorption peak at this point is attributed to the out-of-plane bending vibration of the benzene ring CH.

[0032] II. TM2 1. Mass spectrometry The results are as follows Figure 4 As shown, distinct peaks can be observed, such as m / z 516.5. Based on mass spectrometry analysis, the molecular weight of the obtained compound is equal to the calculated value, and its chemical formula is C. 37 H 30 N3 + It has a molecular weight comparable to that of the structure shown in TM2.

[0033] 2. Ultraviolet-Visible Spectrum A concentration of 1×10⁻⁶ was prepared using dimethyl sulfoxide. -5 A mol / L TM2 solution. The UV spectrum of TM2 at room temperature is as follows. Figure 5 As shown in the figure, the compound exhibits an absorption peak around 261 nm, indicating strong absorption in this wavelength range. A distinct absorption band also exists at 366 nm, suggesting electronic transitions at the ligand center. The peak at 261 nm for TM2 is the absorption peak of the π→π* transition of the aromatic ring. The peak at 366 nm is related to the large conjugated system formed by the vinyl-bridged benzene ring and the heterocycles on both sides. The conjugation effect of the C=C double bond and the aromatic ring expands the delocalization range of π electrons, further reducing the energy level difference of the π→π* transition, resulting in a redshift of the absorption wavelength.

[0034] 3. Infrared spectroscopy like Figure 6 As shown, the infrared spectral data of TM2 is as follows: IR(KBr,cm -1 ):3414.38(m),2925.25(m),2854.44(m),1637.59(s),1617.48(s),1518.77(s),1440.23(s),1383.91(s),1352.42 (s),1269.53(s),1138.80(s),1069.92(s),989.24(s),947.82(s),861.98(s),806.47(s),617.31(m),515.33(m). The infrared spectrum is at 3414.38 cm⁻¹ -1 The bands at 2925.25 and 2854.44 cm⁻¹ show moderate-intensity absorption, attributed to the NH stretching vibration in the compound. Due to hydrogen bonding or environmental influences, they exhibit moderately strong and broad peaks, reflecting the vibrational characteristics of intramolecular / intermolecular NH bonds. -1 The stretching vibrations corresponding to the alkyl side chains at the 2930 cm⁻¹ position correspond to the asymmetric stretching theory of alkanes. -1The theoretical value of symmetrical stretching is 2850 cm. -1 The match is very close, confirming the presence of saturated alkyl side chains in the molecule. (1637.59, 1617.48 cm) -1 Corresponding to the C=N stretching vibration of heterocyclic rings and the skeletal conjugation vibration of aromatic rings: The C=N bond is conjugated with the π bond of the aromatic ring, and the electron delocalization leads to a decrease in the bond force constant, causing the stretching vibration wavenumber to redshift to 1600-1650 cm⁻¹. -1 Within this region, the aromatic ring skeletal vibrations, due to enhanced conjugation, show increased peak intensity and couple with C=N vibrations, forming characteristic peaks in this area. These peaks reflect the large π-conjugated structure of the molecule and relate to the conjugated double bonds and heterocyclic systems in the associated structural formula. (1518.77, 1440.23 cm⁻¹) -1 The peak at this point highly matches the skeletal vibrations of fused-ring aromatic hydrocarbons. Due to intercyclic conjugation, the number and position of skeletal vibrational peaks in polycyclic aromatic hydrocarbons shift, directly confirming the presence of a polycyclic aromatic ring structure in the molecule. (1383.91 cm⁻¹) -1 In the heterocyclic structure, the CN bond is conjugated with the aromatic ring, resulting in a decrease in the stretching vibration wavenumber and exhibiting characteristic absorption. This is related to the heterocyclic side chain structure, 1138.80 cm⁻¹. -1 The in-plane bending vibration of the alkyl side chain couples with the CN vibration to form a complex peak, reflecting the connection mode between the alkyl group and the heterocycle. This peak is located at 515.33-989.24 cm⁻¹. -1 The low wavenumber region reflects bending vibrations of the molecular skeleton and deformation vibrations of heterocycles. Because it involves the collective motion of massive atoms, the wavenumbers are as low as 500-1000 cm⁻¹. -1 The peaks are complex and can help verify the rigidity and conjugation of the molecular skeleton, as well as the complex multi-cyclic conformation of the associated structural formula.

[0035] Example 2 In this embodiment, another method for preparing the fluorescent probe TM2 is provided, including the following steps: Dissolve 0.10 g of acenaphthene, 0.30 g of terephthalaldehyde, and 1.0 g of ammonium acetate in 12 ml of toluene. Add the solution to a 100 ml three-necked flask and stir in a 90 °C water bath for 3 h at a speed of 400-600 r / min with continuous stirring. After the solution color changes from yellow to tan, continue heating for another 3 h. After the reaction is complete, cool, filter, and wash three times successively with toluene, 10% sodium bicarbonate, and deionized water to obtain a tan powder, i.e., TM1.

[0036] Step (2) is as follows: Take 0.15 g of TM1 in a 100 ml three-necked flask, add 0.2 g of 1,1,2-trimethyl-3-(4-butyl nitrate)-1H-benzo[E]indole inner salt, and add 30 ml of anhydrous ethanol. Accurately transfer 40 μl of piperidine into the round-bottom flask using a 100 μl pipette, stir to dissolve, and the solution turns yellow. Heat to 75 °C and reflux; the solution changes from a yellow liquid to a deep red liquid. Continue heating and reflux for 28 h. Evaporate the solvent to obtain a reddish-black solid. Separation and purification: Dissolve the obtained crude product in an appropriate amount of CH2Cl2, extract three times with deionized water, collect the organic phase, evaporate the CH2Cl2 to dryness, and obtain a reddish-black powder.

[0037] Example 3 In this embodiment, another method for preparing the fluorescent probe TM2 is provided, including the following steps: Dissolve 0.20 g of acenaphthene, 0.40 g of terephthalaldehyde, and 1.5 g of ammonium acetate in 20 ml of toluene. Add the solution to a 100 ml three-necked flask and stir in a 98 °C water bath for 1.5 h at a speed of 400-600 r / min. After the solution color changes from yellow to tan, continue heating for another 1 h. After the reaction is complete, cool, filter, and wash three times successively with toluene, 10% sodium bicarbonate, and deionized water to obtain a tan powder, i.e., TM1.

[0038] Step (2) is as follows: Take 0.25 g of TM1 in a 100 ml three-necked flask, add 0.3 g of 1,1,2-trimethyl-3-(4-butyl nitrate)-1H-benzo[E]indole inner salt, and add 50 ml of anhydrous ethanol. Accurately transfer 70 μl of piperidine into the round-bottom flask using a 100 μl pipette, stir to dissolve, and the solution turns yellow. Heat to 85 °C and reflux; the solution changes from a yellow liquid to a deep red liquid. Continue heating and reflux for 20 h. Evaporate the solvent to obtain a reddish-black solid. Separation and purification: Dissolve the obtained crude product in an appropriate amount of CH2Cl2, extract three times with deionized water, collect the organic phase, evaporate the CH2Cl2 to dryness, and obtain a reddish-black powder.

[0039] Example 4 In this embodiment, TM2 is provided for detecting HSO3. - The application specifically involves detection using ultraviolet spectroscopy, and the detection method is as follows: Prepare 1×10⁻⁶ solutions using dimethyl sulfoxide. -5 mol / L TM2 (prepared in Example 1) solution and HSO3 - The solution was used to determine the effect of adding different volumes of HSO3 on TM2. - The subsequent spectral changes, such as Figure 7 As shown. With HSO3 -With increasing volume (0-300 μL), the intensity of the characteristic absorption peak at 366 nm of TM2 shows a regular increasing trend. This enhancement of the 366 nm absorption peak may originate from HSO3. - Nucleophilic addition of C=C to TM2 forms a new conjugated system, further optimizing the energy level difference. Combined with literature reports, HSO3... - It can react with the carbon-carbon double bond (C=C) in the molecule to form an intermediate (-CH2-CH(SO3⁻)-), leading to an enhanced π→π* transition (366 nm) of the original ligand. This result indicates that TM2 enhances the π→π* transition of HSO3. - It has good responsiveness.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fluorescent probe compound, characterized in that, The compound has the structure shown in Formula I, or is a pharmaceutically acceptable salt, ester, or solvate of the compound shown in Formula I, a tautomer, a meso compound, a racemic compound, a stereoisomer, a metabolite, or a prodrug: Formula I is as follows: Formula I.

2. The fluorescent probe compound according to claim 1, characterized in that, The pharmaceutically acceptable salts include inorganic or organic salts of compounds represented by Formula I, wherein the inorganic salts include salts formed with inorganic acids, the inorganic acids being, but not limited to, hydrochloric acid, sulfuric acid, nitric acid, or hydrobromic acid, and the organic salts include salts formed with organic acids, the organic acids being, but not limited to, methanesulfonic acid, toluenesulfonic acid, or trifluoroacetic acid.

3. The method for preparing the fluorescent probe compound according to claim 1 or 2, characterized in that, Includes the following steps: (1) Dissolve acenaphthene, terephthalaldehyde and ammonium acetate in an organic reagent to obtain a solution. Heat the solution in a water bath to 90~98℃ and react for 1.5~3h. After the solution changes color, continue the reaction for 1~3h. After the reaction is completed, filter and retain the solid part to obtain intermediate TM1. (2) Dissolve intermediate TM1, 1,1,2-trimethyl-3-(4-butyl nitrate)-1H-benzo[E]indole inner salt and piperidine in an alcohol solvent, heat to 75~85℃ and react. After the solution color turns dark red, continue the reaction for 20~28h. After the reaction is completed, remove the solvent to obtain crude TM2. The reaction route of the above preparation method is as follows: 。 4. The method for preparing the fluorescent probe compound according to claim 3, characterized in that, In step (1), the organic reagent is toluene; the ratio of quinone, terephthalaldehyde, ammonium acetate and toluene is 0.1~0.2g: 0.3~0.4g: 1~1.5g: 12~20mL.

5. The method for preparing the fluorescent probe compound according to claim 3, characterized in that, In step (1), after the reaction is completed, the solid part is separated by filtration. The separated solid part also needs to be washed. The washing is carried out by the solvent of the reaction system, sodium bicarbonate solution and water in sequence.

6. The method for preparing the fluorescent probe compound according to claim 3, characterized in that, In step (2), the alcohol solvent is anhydrous ethanol; the feeding ratio of the intermediate TM1, 1,1,2-trimethyl-3-(4-nitrate butyl)-1H-benzo[E]indole inner salt, piperidine and anhydrous ethanol is 0.15~0.25g: 0.2~0.3g: 40~70μL: 30~50mL.

7. The method for preparing the fluorescent probe compound according to claim 3, characterized in that, In step (2), after the reaction is completed, the solvent is removed by evaporation or vacuum distillation to obtain crude TM2. The crude TM2 is purified by liquid-liquid extraction, which involves dissolving the crude TM2 with an organic reagent, then extracting with water, and retaining the organic phase to evaporate the solvent to obtain TM2 solid powder.

8. A composition, characterized in that, The composition comprises an active dose of the fluorescent probe compound of claim 1 or 2.

9. The use of the fluorescent probe compound of claim 1 or 2, or the composition of claim 8, in the detection of sulfite.

10. A method for detecting sulfite, characterized in that, The detection includes using the fluorescent probe compound of claim 1 or 2, or the composition of claim 8; the detection method steps are as follows: Add the fluorescent probe compound of claim 1 or 2 to the test solution and detect the absorption peak intensity at 366 nm; if the absorption peak intensity increases, it indicates that sulfite ions are present in the test environment.

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