Preparation method and application of a BODIPY-based ratiometric fluorescent probe for detecting sulfite

Abstract

The present invention discloses a BODIPY-based ratiometric fluorescent probe for detecting sulfite, its preparation method, and application. The fluorescent probe is 2,8-bis(2-(benzothiazol-2-yl)-2-cyanovinyl)-10-(furan-2-yl)-1,3,7,9-tetramethyl-5H-dipyrroledifluoroborane complex. The present invention utilizes 2,8-diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyl-dipyrroledifluoroborane as a raw material, and carries out a condensation reaction with 2-(benzothiazol-2-yl)acetonitrile to obtain the compound 2,8-bis(2-(benzothiazol-2-yl)-2-cyanovinyl)-10-(furan-2-yl)-1,3,7,9-tetramethyl-5H-dipyrroledifluoroborane complex (abbreviated as BODIPY-DBC). When a solution of the compound BODIPY‑DBC reacts with sulfite, the solution changes color from purple to yellow under sunlight; under ultraviolet light at a wavelength of 365 nm, the solution's fluorescence changes from orange to green. BODIPY‑DBC can sensitively detect sulfite content in solutions, with high sensitivity (detection limit of 33.12 nM), fast response, good selectivity, and a wide detection range. It holds great promise as a fluorescent probe for sulfite detection.

Description

Technical Field

[0001] The invention belongs to the technical field of fine organic synthesis and relates to a BODIPY-based ratiometric fluorescent probe for detecting sulfite and a preparation method and application thereof. Background Art

[0002] Sulfite, an important derivative of sulfur dioxide, is an indispensable additive in food storage. It is widely used as an antioxidant, bleaching agent, and enzyme inhibitor to extend the storage life of food, maintain food freshness, and reduce economic losses. Sulfite can also act as a gaseous signaling molecule involved in human redox homeostasis, cell signaling, and physiological and pathological processes. However, excessive intake of sulfite can cause some common respiratory diseases, cardiovascular diseases, and white matter diseases. Considering the potential threat of sulfite to human health, many countries have strictly limited the daily intake of sulfite to 0-0.7 mg / kg. Therefore, it is of great significance to develop a highly sensitive and selective detection method for sulfite.

[0003] Traditional methods for sulfite detection include titration, electrochemistry, chromatography, and capillary electrophoresis. These methods are suitable for hematoma testing but fall short of the requirements for intracellular and in vivo monitoring. Compared to traditional analytical detection methods, fluorescent probes have been widely used in fields such as environmental science and life sciences due to their advantages, including rapid detection, high sensitivity, good selectivity, ease of use, and excellent biocompatibility. For sulfite detection in particular, numerous fluorescent probes with diverse mechanisms and fluorophores have been reported. Since the recognition mechanism is primarily based on dehydrogenation or addition reactions, the choice of fluorophore significantly influences optical properties and practical performance. Sulfite probes are typically composed of a variety of common fluorophores, such as coumarins, carbazoles, flavonols, and rhodamines. However, there are no reports on the synthesis of a novel fluorescent probe, BODIPY-DBC, for the detection of sulfite acid using furfural as a raw material. The probe, BODIPY-DBC, possesses both colorimetric and ratiometric detection capabilities, offering advantages such as a wide detection range, high sensitivity, and good selectivity, making it of great significance for sulfite detection. Summary of the Invention

[0004] In response to the shortcomings of the prior art, the present invention aims to provide a BODIPY-based ratiometric fluorescent probe for detecting sulfite that meets the requirements for sulfite detection. Another technical problem addressed by the present invention is to provide a method for preparing a BODIPY-based ratiometric fluorescent probe for sulfite detection. A further technical problem addressed by the present invention is to provide a use of a BODIPY-based ratiometric fluorescent probe for sulfite detection in sulfite detection.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A BODIPY-based ratiometric fluorescent probe for detecting sulfite is 2,8-bis(2-(benzothiazol-2-yl)-2-cyanovinyl)-10-(furan-2-yl)-1,3,7,9-tetramethyl-5H-dipyrroledifluoroborane complex (abbreviated as BODIPY-DBC, whose structural formula is:

[0007]

[0008] The method for preparing a BODIPY-based ratiometric fluorescent probe for detecting sulfite comprises the following steps:

[0009] 1) Dissolve 2,8-diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyldipyrroledifluoroborane (1 mmol, 357 mg), 2-(benzothiazol-2-yl)acetonitrile (1-3 mmol, 161-483 mg), and triethylamine (2-4 mmol, 202-404 mg) in 10-20 mL of ethanol and add to a round-bottom flask. Reflux under nitrogen for 3-5 h until the reaction is complete (monitored by TLC).

[0010] 2) The reaction solution was concentrated under reduced pressure and extracted with dichloromethane and saturated brine. The organic phase was washed, dried, and distilled to obtain a crude product, which was further purified by silica gel column chromatography (petroleum ether / ethyl acetate = 3 / 1, v / v) to obtain BODIPY-DBC as a dark purple solid.

[0011] The fluorescent probe BODIPY-DBC solution reacts with sulfite, and the color of the solution changes from purple to yellow under sunlight; under ultraviolet light with a wavelength of 365nm, the fluorescent color of the solution changes from orange to green.

[0012] The fluorescent probe BODIPY-DBC is used to detect the sulfite content in the solution. The detection range is 0-150μM and below. It has high sensitivity (the detection limit reaches 33.12nM), fast response speed, good selectivity, and wide detection range.

[0013] Beneficial effects: Compared with the prior art, the present invention utilizes 2,8-diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyldipyrroledifluoroborane as a raw material to undergo a condensation reaction with 2-(benzothiazol-2-yl)acetonitrile. The prepared BODIPY-DBC can specifically identify sulfite and can quickly and sensitively detect the sulfite content in the solution. It has the characteristics of high sensitivity (detection limit reaches 33.12 nM), fast response speed, good selectivity, wide detection range, etc., and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 BODIPY-DBC and different concentrations of SO3 2- Fluorescence spectrum of

[0015] Figure 2 Figure F is the fluorescence intensity ratio of BODIPY-DBC to different metal ions, anions and amino acids. 524nm / F 571nm (az: blank, SO3 2- , Hg 2+ , Ag + , Fe 2+ , Cu 2+ , K + , Ca 2+ , Zn 2+ , Ba 2+ , Mn 2+ , I - , Br - , Cl - , H2S, Hcy, Thr, Arg, GSH, Tyr, Cys, Leu, Val, Trp, Asn, Gly). DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to specific embodiments.

[0017] Example 1

[0018] Preparation of fluorescent probe BODIPY-DBC, the reaction formula is as follows:

[0019]

[0020] (1) 2,8-Diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyldipyrroledifluoroborane (1 mmol, 357 mg), 2-(benzothiazol-2-yl)acetonitrile (2 mmol, 322 mg), and triethylamine (2 mmol, 202 mg) were dissolved in 20 mL of ethanol and added to a round-bottom flask. The mixture was refluxed under nitrogen for 4 h until the reaction of the raw materials was complete (monitored by TLC).

[0021] (2) The reaction solution was concentrated under reduced pressure and extracted with dichloromethane and saturated brine. The organic phase was washed, dried, and distilled to obtain a crude product. The crude product was further purified by silica gel column chromatography (petroleum ether / ethyl acetate = 3 / 1, v / v) to obtain a dark purple solid BODIPY-DBC. 1H NMR (600MHz, Chloroform-d) δ: 8.21 (s, 1H), 8.09-8.04 (m, 2H), 7.91 (dd, J = 8.0, 4.4Hz, 2H), 7.53 (t, J = 8.0Hz, 2H) ),7.47-7.41(m,2H),7.22(s,1H),6.20(s,1H),5.35(s,2H),2.69(s,3H),2.60(s,3H),2.48(s,3H),2.32(s,3H).

[0022] Example 2

[0023] BODIPY-DBC was prepared into 1×10 -5 M PBS buffer solution, dissolve sodium sulfite in PBS buffer to prepare a concentration of 0, 1.0×10 -5 , 2.0×10 -5 , 3.0×10 -5 , 4.0×10 -5 , 5.0×10 -5 , 6.0×10 -5 , 7.0×10 -5 , 8.0×10 -5 , 9.0×10 -5 , 1.0×10 -4 , 1.1×10 -4 , 1.2×10 -4 , 1.3×10 -4 , 1.4×10 -4 , 1.5×10 -4 M solution. The fluorescence spectrophotometer was used to measure the SO3 2- The fluorescence emission spectrum of BODIPY-DBC in the presence of Figure 1 The results show that as SO3 2- As the concentration gradually increases, the fluorescence emission intensity of the probe at 571 nm gradually decreases, while the fluorescence emission intensity at 524 nm gradually increases. This shows that the compound can be used as a fluorescent probe for sensitive detection of sulfite content in solution, with a detection limit of sulfite as low as 33.12 nm.

[0024] Example 3

[0025] BODIPY-DBC was prepared into 1×10 -5 M PBS buffer solution, and different metal ions, anions and amino acids were dissolved in PBS buffer to a concentration of 1.0×10 -4The fluorescence emission spectra of BODIPY-DBC in the presence of different metal ions, anions and amino acids were measured using a fluorescence spectrophotometer using fluorescence spectrometry. Figure 2 The results showed that the addition of sulfite significantly increased the fluorescence emission intensity ratio of the probe, while the addition of metal ions, anions, and amino acids did not significantly change the fluorescence spectrum of the probe. This suggests that the compound can be used as a fluorescent probe specifically for the detection of sulfite.

Claims

1. A BODIPY-based ratiometric fluorescent probe for detecting sulfite, characterized in that: The fluorescent probe is a 2,8-bis(2-(benzothiazol-2-yl)-2-cyanovinyl)-10-(furan-2-yl)-1,3,7,9-tetramethyl-5H-dipyrrole difluoroborane complex. The 2,8-bis(2-(benzothiazol-2-yl)-2-cyanovinyl)-10-(furan-2-yl)-1,3,7,9-tetramethyl-5H-dipyrrole difluoroborane complex is referred to as BODIPY-DBC. Its structural formula is:

2. The method for preparing a BODIPY-based ratiometric fluorescent probe for detecting sulfite according to claim 1, wherein: 2,8-diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyldipyrroledifluoroborane is used as a raw material and subjected to a condensation reaction with 2-(benzothiazol-2-yl)acetonitrile to obtain the compound BODIPY-DBC.

3. The method for preparing a BODIPY-based ratiometric fluorescent probe for detecting sulfite according to claim 2, wherein: The specific steps include: 1) Dissolve 1 mmol, 357 mg of 2,8-diformyl-10-(furan-2-yl)-1,3,7,9-tetramethyldipyrroledifluoroborane, 1-3 mmol, 161-483 mg of 2-(benzothiazol-2-yl)acetonitrile, 2-4 mmol, and 202-404 mg of triethylamine in 10-20 mL of ethanol and add to a round-bottom flask. Reflux under nitrogen for 3-5 hours until the reaction is complete, monitoring by TLC. 2) The reaction solution was concentrated under reduced pressure and extracted with dichloromethane and saturated brine. The organic phase was washed, dried, and distilled to obtain a crude product, which was further purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate (v / v) as the eluent to obtain BODIPY-DBC as a dark purple solid.

4. Use of the BODIPY-based ratiometric fluorescent probe for detecting sulfite according to claim 1 in detecting sulfite.

5. The use according to claim 4, characterized in that The fluorescent probe BODIPY-DBC solution reacts with sulfite, and the color of the solution changes from purple to yellow under sunlight; under ultraviolet light with a wavelength of 365nm, the fluorescent color of the solution changes from orange to green.

6. The use according to claim 4, characterized in that The fluorescent probe BODIPY-DBC was used to detect the sulfite content in the solution in the detection concentration range of 0 to 150 μM.

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