Near-infrared fluorescence / photoacoustic dual-response probe as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of compounds and preparation thereof, and particularly relates to a near-infrared fluorescence / photoacoustic double-response probe as well as a preparation method and application thereof.The structural formula of the near-infrared fluorescence / photoacoustic double-response probe is shown as a formula (I): # imgabs0 #. The near-infrared fluorescence / photoacoustic double-response probe is synthesized from the probe and compounds such as 3-hydroxythiophenol, sodium hydride, thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate, 4-dimethylaminopyridine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and the like, and the near-infrared fluorescence / photoacoustic double-response probe has the advantages of being rapid in response and high in sensitivity and can be applied to quantitative detection and imaging of polysulfide.

Description

Technical Field

[0001] The present invention belongs to the technical field of compounds and their preparation, and particularly relates to a near-infrared fluorescence / photoacoustic dual-response probe and a preparation method and application thereof. Background Art

[0002] Near-infrared fluorescence and photoacoustic probes are cutting-edge tools in biomedical imaging. Near-infrared fluorescence signals offer low background interference and strong tissue penetration, effectively enhancing imaging in living organisms and tissues. Combining near-infrared fluorescent dyes with high-spatial-resolution ultrasound detection and high-contrast optical imaging with photoacoustic imaging can capture molecular information from living organisms, significantly improving the specificity, penetration depth, and spatial resolution of tissue imaging. The development of low-toxic near-infrared fluorescence / photoacoustic dual-response probes for quantitative fluorescence / photoacoustic dual-modality detection and precise imaging of deep tissues is of paramount importance.

[0003] Hydrogen polysulfide, as a reactive sulfur species, plays a crucial role in activating ion channels, promoting transcription factor activation, and regulating tumor suppressor activity. Therefore, real-time visualization and imaging of polysulfide are of great significance for disease diagnosis. Near-infrared fluorescent probes for polysulfide detection have been reported, but these probes suffer from long detection times and low sensitivity.

[0004] Therefore, there is an urgent need to develop a fast-response, highly sensitive near-infrared fluorescence / photoacoustic dual-response probe for the detection and imaging of polysulfides. Summary of the Invention

[0005] In response to the technical problems of long detection time and low sensitivity of existing polysulfide detection probes, the present invention provides a near-infrared fluorescence / photoacoustic dual-response probe and its preparation method and application.

[0006] The present invention uses cyanine IR-780 iodide as the skeleton and synthesizes a near-infrared fluorescence / photoacoustic dual-response probe with compounds such as 3-hydroxythiophenol, sodium hydride, thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate, 4-dimethylaminopyridine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide. The probe has the advantages of rapid response and high sensitivity and can be used in the quantitative detection and imaging of polysulfides.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A near-infrared fluorescence / photoacoustic dual-response probe, the structural formula of which is shown in formula (I):

[0009]

[0010] The preparation method of the near-infrared fluorescence / photoacoustic dual-response probe comprises the following steps:

[0011] S1. preparing compound A;

[0012] Compound A was prepared by mixing 3-hydroxythiophenol, sodium hydride and IR-780 iodide in a molar ratio of (1.2-2):1.5:1;

[0013] S2. Preparation of Compound B

[0014] Compound B is prepared using thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate and water; the molar ratio of thiosalicylic acid, benzoyl chloride, sodium bicarbonate and sodium carbonate in every 25-30 mL of water is 1:(0.8-1.5):(2.5-3.2):(1-3);

[0015] S3. Synthesis of near-infrared fluorescence / photoacoustic dual-response probes

[0016] Compound A, 4-dimethylaminopyridine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and compound B were prepared in a molar ratio of 1:0.2:(1-2):(3.5-4.5) to obtain a near-infrared fluorescence / photoacoustic dual response probe.

[0017] It is further defined that the specific preparation process of step S1 is:

[0018] S1.1. Dissolve 3-hydroxythiophenol and sodium hydride in N,N-dimethylformamide solution, stir at room temperature under nitrogen for 10 to 15 minutes, then add IR-780 iodide, react at 50 to 55°C for 20 to 22 hours, and cool to room temperature after completion of the reaction. Then remove the solvent from the reaction product to obtain a crude product.

[0019] S1.2. Using dichloromethane / ethanol as eluent, separate and purify the crude product to obtain compound A.

[0020] It is further defined that in step S1.2, the volume ratio of dichloromethane to ethanol is (40-100):1.

[0021] It is further defined that the specific preparation process of step S2 is:

[0022] S2.1. Dissolve sodium bicarbonate in water to form a sodium bicarbonate solution, then dissolve thiosalicylic acid in the sodium bicarbonate solution and cool to 0°C; then add benzoyl chloride and sodium carbonate, stir at 0°C for 20 to 50 minutes, and then stir at room temperature for another 30 to 60 minutes;

[0023] S2.2. After stirring, acidify with concentrated hydrochloric acid until a white precipitate is formed; collect and wash the precipitate to obtain compound B.

[0024] It is further defined that the specific preparation process of step S3 is:

[0025] S3.1. Dissolve compound B, 4-dimethylaminopyridine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide in anhydrous dichloromethane and stir at room temperature for 5 to 25 minutes to obtain a mixed solution.

[0026] S3.2. Dissolve compound A in anhydrous dichloromethane and mix well; then add the mixture to the mixed solution described in step S3.1 and stir at room temperature for 5 to 6 hours. After the reaction is complete, extract and evaporate under reduced pressure to obtain a crude product;

[0027] S3.3. The crude product is eluted and separated to obtain a near-infrared fluorescence / photoacoustic dual response probe.

[0028] It is further defined that in step S3.3, elution is performed with dichloromethane / methanol, and the volume ratio of dichloromethane to methanol is 50:1 to 100:3.

[0029] Application of the near-infrared fluorescence / photoacoustic dual-response probe in the quantitative detection of polysulfides.

[0030] Application of the near-infrared fluorescence / photoacoustic dual response probe in polysulfide imaging.

[0031] It is further defined that after the near-infrared fluorescence / photoacoustic dual response probe reacts with polysulfide, the color is stable within 5 minutes and strong absorption is generated at 740nm to 780nm.

[0032] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0033] 1. The present invention uses cyanine IR-780 iodide as the skeleton and synthesizes a near-infrared fluorescence / photoacoustic dual-response probe with compounds such as 3-hydroxythiophenol, sodium hydride, thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate, 4-dimethylaminopyridine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide. It has the advantages of rapid response and high sensitivity and can be used in the quantitative detection and imaging of polysulfides.

[0034] 2. The present invention synthesizes a near-infrared fluorescence / photoacoustic dual-response probe with a near-infrared fluorescence emission wavelength, realizes polysulfide fluorescence / photoacoustic dual response, can develop color within 5 minutes, has a fast reaction speed, and good stability.

[0035] 3. Experiments have shown that the synthesized near-infrared fluorescence / photoacoustic dual-response probe exhibits strong absorption at 740nm to 780nm when detecting polysulfides, with peak fluorescence at 764nm. This fluorescence emission band lies within the near-infrared region, resulting in minimal background interference. This indicates that the near-infrared fluorescence / photoacoustic dual-response probe exhibits high accuracy and sensitivity.

[0036] 4. Through research and development, the present invention also found that when the synthesized near-infrared fluorescence / photoacoustic dual-response probe detects polysulfides, there is a linear relationship between the fluorescence intensity and the polysulfide concentration, as well as between the photoacoustic intensity and the polysulfide concentration, which can achieve quantitative detection of polysulfides.

[0037] 5. The present invention also provides a method for preparing a near-infrared fluorescence / photoacoustic dual-response probe, which is convenient to operate and simple to post-process, and is easy to scale up for production. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the H-NMR spectrum of the near-infrared fluorescence / photoacoustic dual-response probe;

[0039] Figure 2 It is the NMR carbon spectrum of the near-infrared fluorescence / photoacoustic dual response probe;

[0040] Figure 3 Figure 5 is the fluorescence emission spectra of the reactions with different concentrations of polysulfide.

[0041] Figure 4 The standard curve for the near-infrared fluorescence / photoacoustic dual-response probe to detect polysulfide concentration;

[0042] Figure 5 Standard curve for the near-infrared fluorescence / photoacoustic dual-response probe detecting the photoacoustic response of polysulfides. DETAILED DESCRIPTION

[0043] The present invention will be described in further detail below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto. Other methods for preparing the compounds of the present invention are considered to be within the scope of the present invention by making some conventional modifications to the reaction conditions of the present invention.

[0044] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0045] Technologies, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods, and equipment should be considered part of the specification.

[0046] It should also be understood that the specific embodiments described above are only used to explain the present invention, and the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the scope of protection of the present invention / invention.

[0047] The present invention provides a near-infrared fluorescence / photoacoustic dual-response probe, the structural formula of which is shown in formula (I):

[0048]

[0049] The present invention also provides a method for preparing a near-infrared fluorescence / photoacoustic dual-response probe, comprising the following steps:

[0050] S1. preparing compound A;

[0051] Compound A was prepared by mixing 3-hydroxythiophenol, sodium hydride and IR-780 iodide in a molar ratio of (1.2-2):1.5:1.

[0052] Illustratively, the molar ratio of 3-hydroxythiophenol, sodium hydride, and IR-780 iodide is 1.2:1.5:1, 1.3:1.5:1, 1.5:1.5:1, 1.8:1.5:1, or 2:1.5:1.

[0053] The specific preparation process of step S1 of the present invention is:

[0054] S1.1. Dissolve 3-hydroxythiophenol and sodium hydride in N,N-dimethylformamide solution, stir at room temperature under nitrogen for 10-15 minutes, then add IR-780 iodide and react at 50-55°C for 20-22 hours. After completion of the reaction, cool to room temperature; then remove the solvent from the reaction product to obtain a crude product.

[0055] In this step, N,N-dimethylformamide is used as a solvent to dissolve the raw materials and needs to be removed after the reaction is completed. Therefore, the amount of N,N-dimethylformamide used is not specifically limited, and it only needs to be sufficient to dissolve all of 3-hydroxythiophenol, sodium hydride, and IR-780 iodide.

[0056] S1.2. Purify the crude product using dichloromethane / ethanol as eluent to obtain compound A.

[0057] Preferably, in step S1.2, the volume ratio of dichloromethane to ethanol is (40-100): 1. Exemplarily, the volume ratio of dichloromethane to ethanol is 40:1, 50:1, 60:1, 70:1, 80:1, 90:1 or 100:1.

[0058] In this step, the structural formula of compound A is as follows:

[0059]

[0060] S2. Preparation of Compound B

[0061] Compound B was prepared using thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate and water.

[0062] The molar ratio of thiosalicylic acid, benzoyl chloride, sodium bicarbonate, and sodium carbonate per 25-30 mL of water is 1:(0.8-1.5):(2.5-3.2):(1-3). Exemplarily, the molar ratio of thiosalicylic acid, benzoyl chloride, sodium bicarbonate, and sodium carbonate per 25-30 mL of water is (1:0.8:2.5:1), (1:0.8:3:1) (1:0.8:3.2:1), (1:1:2.5:1), (1:1:3:1), (1:1:3:2), (1:1:3:3), (1:1:3.2:1), (1:1.5:2.5:1), (1:1.5:3.2:2), or (1:1.5:3.2:3).

[0063] The specific preparation process of step S2 of the present invention is:

[0064] S2.1. Dissolve sodium bicarbonate in water to form a sodium bicarbonate solution, then dissolve thiosalicylic acid in the sodium bicarbonate solution and cool to 0°C; then add benzoyl chloride and sodium carbonate, stir at 0°C for 20 to 50 minutes, and then stir at room temperature for another 30 to 60 minutes;

[0065] S2.2. After stirring, acidify with concentrated hydrochloric acid until a white precipitate is formed; collect and wash the precipitate to obtain compound B.

[0066] S3. Synthesis of near-infrared fluorescence / photoacoustic dual-response probes

[0067] A near-infrared fluorescence / photoacoustic dual-response probe is prepared by mixing compound A, 4-dimethylaminopyridine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and compound B in a molar ratio of 1:0.2:(1-2):(3.5-4.5). Exemplarily, the molar ratio of compound A, 4-dimethylaminopyridine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and compound B is (1:0.2:1:3.5), (1:0.2:1.5:3.5), (1:0.2:2:3.5), (1:0.2:1:4), (1:0.2:1.5:4), (1:0.2:2:4), (1:0.2:1:4.5), (1:0.2:1.5:4.5), or (1:0.2:2:4.5).

[0068] The specific preparation process of step S3 of the present invention is:

[0069] S3.1. Dissolve compound B, 4-dimethylaminopyridine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide in anhydrous dichloromethane (4-5 mL) and stir at room temperature for 5-25 minutes to obtain a mixed solution.

[0070] S3.2. Dissolve compound A in anhydrous dichloromethane (4-5 mL) and mix well. Add the mixture to the mixed solution from step S3.1 and stir at room temperature for 5-6 hours. After the reaction is complete, extract and evaporate under reduced pressure to obtain a blue solid powder, which is the crude product.

[0071] S3.3. The synthesized crude product was eluted and separated with dichloromethane / methanol to obtain a solid powder, namely a near-infrared fluorescence / photoacoustic dual-response probe.

[0072] Preferably, in step S3.3, the volume ratio of dichloromethane to methanol is 50:1 to 100:3. Exemplarily, the volume ratio of dichloromethane to methanol is 50:1, 40:1 or 100:3.

[0073] The near-infrared fluorescence / photoacoustic dual-response probe prepared by the invention has a near-infrared fluorescence emission wavelength and has a fluorescence / photoacoustic dual response for detecting polysulfides.

[0074] The present invention also provides an application of a near-infrared fluorescence / photoacoustic dual-response probe in the quantitative detection of polysulfides.

[0075] The present invention also provides an application of a near-infrared fluorescence / photoacoustic dual-response probe in polysulfide imaging.

[0076] Preferably, upon application, the near-infrared fluorescence / photoacoustic dual-response probe reacts with polysulfides, exhibiting stable color development within 5 minutes and strong absorption at 740 nm to 780 nm. This demonstrates the rapid response and high sensitivity of the near-infrared fluorescence / photoacoustic dual-response probe for polysulfide detection, enabling accurate quantitative detection and precise imaging of polysulfides.

[0077] The preparation method provided by the present invention is described in detail below with several groups of specific embodiments.

[0078] It should be noted that the experimental methods involved in the following examples are conventional methods unless otherwise specified; reagents such as IR-780 iodide and biological materials, unless otherwise specified, can be obtained from commercial channels, or can be synthesized using or according to methods known in the art.

[0079] It should be noted that, unless otherwise specified in the following examples, all reactions were carried out under a nitrogen atmosphere, which means that the reaction flask was connected to a nitrogen balloon or a steel kettle with a volume of approximately 1 L.

[0080] It should be noted that, in the following examples, when column chromatography was used for purification and separation, the column chromatography used 200-300 mesh silica gel produced by Qingdao Ocean Chemical as the carrier.

[0081] It should be noted that the room temperature involved in the following examples is 20°C to 30°C.

[0082] It should be noted that in the following examples, the reaction progress was monitored by thin layer chromatography (TLC), and the developing solvent systems used in the reaction were: dichloromethane and methanol system or dichloromethane and ethanol system. The volume ratio of the solvent was adjusted according to the polarity of the compound, and these adjustments are all existing technologies in the art.

[0083] Example 1

[0084] The preparation method of the near-infrared fluorescence / photoacoustic dual-response probe provided in this embodiment includes the following steps:

[0085] S1. Preparation of Compound A

[0086] S1.1. Dissolve 3-hydroxythiophenol (56.78 mg, 0.45 mmol) and sodium hydride (10.8 mg, 0.45 mmol) in N,N-dimethylformamide solution (4 mL) and stir at room temperature under nitrogen for 15 min to obtain a mixed solution. Then, dissolve IR-780 iodide (200 mg, 0.3 mmol) in 1 mL of N,N-dimethylformamide solution and add the resulting mixture to the mixed solution. The resulting mixture is reacted at 55°C for 20 h. After the reaction is complete, the mixture is cooled to room temperature. Subsequently, the mixture is poured into cold water, and perchloric acid is added to remove the solvent to obtain a crude product.

[0087] S1.2. Purify the crude product by column chromatography using dichloromethane / ethanol (v / v, 100:1) as eluent to obtain a blue-green powder, compound A (86.4 mg, 67.3% yield).

[0088] S2. Preparation of fluorescent / photoacoustic near-infrared fluorescent probe intermediate, i.e., compound B

[0089] S2.1. Dissolve sodium bicarbonate (1.63 g, 19.46 mmol) in 25 mL of water to form a sodium bicarbonate solution; then dissolve thiosalicylic acid (1 g, 6.48 mmol) in the sodium bicarbonate solution and cool to 0°C. Then, add benzoyl chloride (912 mg, 6.48 mmol) and sodium carbonate (1.37 g, 12.98 mmol). Stir the resulting reaction mixture at 0°C for 30 min and then at room temperature for another 60 min.

[0090] S2.2. After the reaction, the reaction product was acidified with concentrated hydrochloric acid until a white precipitate was formed. The precipitate was collected and washed with cold water to obtain compound B (1.4 g, yield 81.22%).

[0091] S3. Preparation of near-infrared fluorescence / photoacoustic dual-response probes

[0092] S3.1. Dissolve compound B (124.8 mg, 0.48 mmol) obtained in step S2, 4-dimethylaminopyridine (2.88 mg, 0.024 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (34.79 mg, 0.18 mmol) in 4 mL of anhydrous dichloromethane solvent and stir at room temperature for 15 min to obtain a mixed solution.

[0093] S3.2. Dissolve compound A (50 mg, 0.12 mmol) obtained in step S1 in 5 mL of anhydrous dichloromethane and mix well. Then add the mixture to the mixed solution from step S3.1. After mixing, stir at room temperature for 5 h. After the reaction is complete, extract with water and dichloromethane, and evaporate under reduced pressure to obtain a blue solid powder as the crude product.

[0094] S3.3. The synthesized crude product was eluted with dichloromethane / methanol (v / v, 50:1) to separate and obtain a solid powder, namely a near-infrared fluorescence / photoacoustic dual-response probe (mass 34 mg, yield 42.5%), whose structural formula is shown in formula (I).

[0095] Example 2 to Example 5

[0096] The methods for preparing the target compound represented by formula (I) in Examples 2 to 5 are the same as those in Example 1. The difference from Example 1 is the parameters in the preparation process, see Table 1 for details.

[0097] Table 1 Preparation parameters of Examples 2 to 5

[0098]

[0099] Furthermore, in order to illustrate the performance of the near-infrared fluorescence / photoacoustic dual-response probe prepared by the present invention, the following experimental verification was performed.

[0100] Test 1

[0101] Using nuclear magnetic resonance ( 1 H-NMR, 13 C-NMR) to determine the structural characteristics of the near-infrared fluorescence / photoacoustic dual-response probe prepared in Example 1.

[0102] In the present invention, the structure of the near-infrared fluorescence / photoacoustic dual response probe is determined by nuclear magnetic resonance ( 1H-NMR, 13 C-NMR). 1 H-NMR, 13 C-NMR chemical shifts (δ) are given in parts per million (ppm). 1 H-NMR, 13 C-NMR measurements were performed using a Bruker Avance III HD 600 NMR spectrometer, using deuterated chloroform (CDCl3) as the solvent. TMS (0 ppm) was used as the reference standard. When multiple peaks are present, the following abbreviations are used: s (singlet), d (doublet), t (triplet), m (multiplet), br (broadened), dd (doublet of doublets), and brs (broadened singlet). Coupling constants are expressed in Hertz (Hz).

[0103] The results of the test are as follows Figure 1 and Figure 2 shown.

[0104] from Figure 1 and Figure 2 It can be seen that the structural characterization data results of the near-infrared fluorescence / photoacoustic dual-response probe are as follows:

[0105] Proton spectrum: 1 H NMR(600MHz,Chloroform-d)δ8.20(d,J=14.6Hz,1H),8.14(d,J=7.7Hz,1H),7.92(d,J=7.8Hz, 1H),7.62(d,J=7.9Hz,1H),7.58(t,J=7.7Hz,1H),7.55-7.47(m,2H),7.41(t,J=7.2Hz,2H),7.3 9-7.30(m,6H),7.16(s,1H),7.06(dd,J=8.3,2.2Hz,1H),6.89(s,1H),6.69(d,J=14.6Hz,1H),4 .36(t,J=7.3Hz,2H),2.69-2.62(m,4H),1.68(s,6H),1.57-1.47(m,4H),0.95(t,J=7.4Hz,3H).

[0106] Carbon spectrum: 13C NMR(151MHz,Chloroform-d)δ189.51,178.89,176.13,164.16,151.47,151.15,1 46.31,142.53,141.43,137.49,136.45,135.02,134.09,133.87,133.34,133.18 ,131.84,131.46,130.01,129.99,129.93,129.56,128.98,128.74,128.37,127.66,122.61,121.61,117.98,113.76,108.34,51.33,47.70,25.67,22.80,11.50.

[0107] Test 2

[0108] The polysulfide was detected by fluorescence using the compound of formula (I) prepared in Example 1.

[0109] 1. Solution preparation

[0110] The near-infrared fluorescence / photoacoustic dual response probe prepared in Example 1 was mixed with dimethyl sulfoxide to prepare a solution, which was designated as probe stock solution b. The concentration of the near-infrared fluorescence / photoacoustic dual response probe in the probe stock solution b was 1 mmol / L.

[0111] The phosphate solution used in reagent stock solution a is HyClone TM (1X) product. The pH value of the reagent stock solution a is 7.4, and the molar concentration of phosphate is 10 mmol / L.

[0112] The sodium tetrasulfide required for in vitro detection of polysulfides is prepared according to conventional operating methods in the art, and the concentration of the prepared sodium tetrasulfide mother solution is 10 mmol / L.

[0113] 2. The test process is:

[0114] 1) When measuring fluorescence emission spectroscopy, the excitation wavelength was 700 nm, and the fluorescence intensity of the reagent blank at an emission wavelength of 730 nm was measured. The reagent blank was a mixture of reagent stock solution a and probe stock solution b in a volume ratio of 50:1.

[0115] 2) The probe stock solution b was dissolved in the reagent stock solution a, and the volume was fixed to 2 mL with the reagent stock solution a to form a mixed solution. At this time, the concentration of the near-infrared fluorescence / photoacoustic dual response probe in the mixed solution was 20 μmol / L.

[0116] 3) Then, equal amounts of the mixed solution were taken and added to a series of polysulfide (sodium tetrasulfide) standard solutions with different concentrations, wherein the concentrations of polysulfide were: 0 μmol / L, 5 μmol / L, 10 μmol / L, 15 μmol / L, 20 μmol / L, 30 μmol / L, 40 μmol / L, 50 μmol / L, 60 μmol / L, 80 μmol / L, 90 μmol / L and 100 μmol / L; the volume of the series of polysulfide standard solutions with different concentrations was 2 mL.

[0117] 4) The series of polysulfide standard solutions prepared above were reacted at 37°C for 5 min, and their fluorescence excitation spectra and fluorescence emission spectra were measured using a fluorescence instrument F-7000. The slit widths for excitation and emission were 10 nm, and the excitation wavelength was 700 nm. The emission spectra of polysulfide standard solutions with different concentrations were obtained as follows: Figure 3 shown.

[0118] from Figure 3 It can be seen that in the absence of polysulfides, the fluorescence intensity at 764 nm is F0, and the probe shows weak fluorescence at 764 nm. As the concentration of polysulfides increases, the fluorescence intensity at 764 nm greatly increases, indicating that the probe has a good optical response to polysulfides.

[0119] 5) When measuring fluorescence emission spectra, the excitation wavelength is 700 nm, and the fluorescence intensity of a series of polysulfide standard solutions with different concentrations at an emission wavelength of 764 nm is measured, which is recorded as F. F has multiple sets of values. Then, the concentration C of polysulfide is used as the horizontal axis and the corresponding fluorescence intensity value F is used as the vertical axis to draw a standard curve. The standard curve is as follows: Figure 4 As shown; after linear fitting between concentration and fluorescence intensity, the regression equation of linear fitting is:

[0120] F=9.90×C+43.79(R 2 =0.9856)

[0121] Where C is the concentration of polysulfide in μmol / L.

[0122] Through the standard curve equation, it was found that the polysulfide concentration was linearly related between 2.5μmol / L and 60μmol / L, and the square of the correlation R reached above 0.98.

[0123] Test 3

[0124] Photoacoustic detection of polysulfides was performed using the compound of formula (I) prepared in Example 1, and the specific steps are as follows.

[0125] 1) Reagent stock solution a and probe reagent stock solution b were mixed at a volume ratio of 50:1 and recorded as a blank sample. Photoacoustic response is a "light → heat → sound" conversion process, not photoluminescence (such as fluorescence or phosphorescence), and therefore does not involve photon re-emission. Photoacoustic response measurement uses 735 nm as the excitation wavelength and measures the photoacoustic intensity.

[0126] 2) Dissolve the probe reagent stock solution b in the reagent stock solution a, and dilute the volume to 2 mL with the reagent stock solution a to form a mixed solution. At this time, the concentration of the near-infrared fluorescence / photoacoustic response probe in the mixed solution is 20 μmol / L.

[0127] 3) Then, equal amounts of the mixed solution were taken and added to a series of polysulfide standard solutions with different concentrations, wherein the concentrations of polysulfide were: 20 μmol / L, 40 μmol / L, 60 μmol / L, 80 μmol / L and 100 μmol / L; the volume of the polysulfide standard solutions with different concentrations was 2 mL.

[0128] 4) When the photoacoustic response is measured, the excitation wavelength is 735 nm, and the photoacoustic intensity of a series of polysulfide standard solutions with different concentrations is measured, which is recorded as P. P has multiple sets of values. The concentration C of polysulfide is used as the horizontal axis and the corresponding photoacoustic intensity value P is used as the vertical axis to draw a standard curve. The standard curve is as follows: Figure 5 As shown; after linear fitting between concentration and photoacoustic intensity, the regression equation of linear fitting is:

[0129] P = 4.42 × C - 42.13 (R 2 =0.9950)

[0130] Where C is the concentration of polysulfide in μmol / L.

[0131] The standard curve equation shows that the polysulfide concentration is linearly related between 20 μmol / L and 100 μmol / L, and the square of the correlation R is above 0.99, indicating a good linear relationship.

[0132] The above experiments show that the near-infrared fluorescence / photoacoustic dual-response probe represented by formula (I) of the present invention has the following characteristics.

[0133] 1. The near-infrared fluorescence / photoacoustic dual-response probe provided by the present invention itself has an extremely low fluorescence signal in the solution and a low background signal; however, with the addition of polysulfide, the fluorescence intensity of the near-infrared fluorescence / photoacoustic dual-response probe will be significantly enhanced after reacting with the polysulfide, producing strong absorption at 740nm~780nm, and the fluorescence is strongest at 764nm. This fluorescence emission band is in the near-infrared light region, with little background interference, and this probe has high accuracy and sensitivity.

[0134] 2. The near-infrared fluorescence / photoacoustic dual-response probe provided by the present invention has a fast fluorescence reaction speed and can develop stable color within 5 minutes.

[0135] 3. The near-infrared fluorescence / photoacoustic dual-response probe provided by the present invention reacts with polysulfides, and the fluorescence intensity increases with the increase of polysulfide concentration. When the polysulfide concentration is between 2.5 μmol / L and 60 μmol / L, the fluorescence intensity and the polysulfide concentration are linearly related, and quantitative detection of polysulfides can be performed.

[0136] 4. The near-infrared fluorescence / photoacoustic dual-response probe provided by the present invention reacts with polysulfides, and the photoacoustic intensity increases with the increase of polysulfide concentration. When the polysulfide concentration is between 20 μmol / L and 100 μmol / L, the photoacoustic intensity and the polysulfide concentration are linearly related, and quantitative detection of polysulfides can be performed.

[0137] In summary, the near-infrared fluorescence / photoacoustic dual-response probe prepared in the present invention can be used to detect polysulfides and has great application prospects in the fields of food, living biological imaging, etc.

[0138] The above experiments demonstrate that using a test solution containing the near-infrared fluorescence / photoacoustic dual-response probe of the present invention, by comparing fluorescence and photoacoustic intensities, the presence of polysulfides in a biological sample can be intuitively determined, and polysulfide concentrations can also be quantitatively determined. The compound prepared by the present invention exhibits rapid color development within 5 minutes in polysulfide detection, demonstrating high sensitivity for polysulfide identification.

[0139] The above experimental study was based on the near-infrared fluorescence / photoacoustic dual response probe prepared in Example 1. When the near-infrared fluorescence / photoacoustic dual response probe prepared in Examples 2 to 5 was tested, it was found that color was developed within 5 minutes and strong absorption was generated at 740nm to 780nm. It has the advantages of rapid response and high sensitivity. There is a linear relationship between the fluorescence intensity and the polysulfide concentration, as well as between the photoacoustic intensity and the polysulfide concentration. It has a high sensitivity for the identification of polysulfides and can be used in the quantitative detection and imaging of polysulfides.

[0140] The above are several relatively preferred implementation methods of the preparation method of the present invention, but they cannot be used as limitations on the technical solutions protected by the present invention. Any replacement solutions obtained by ordinary technicians in this field without making creative work based on the technical ideas of the present invention should fall within the scope of protection of the present invention.

Claims

1. A near-infrared fluorescence / photoacoustic dual response probe, characterized in that: The structural formula is shown in formula (I):

2. The method for preparing the near-infrared fluorescence / photoacoustic dual response probe according to claim 1, wherein The preparation method comprises the following steps: S1. preparing compound A; Compound A was prepared by mixing 3-hydroxythiophenol, sodium hydride and IR-780 iodide in a molar ratio of (1.2-2):1.5:1; S2. Preparation of Compound B Compound B is prepared using thiosalicylic acid, benzoyl chloride, sodium bicarbonate, sodium carbonate and water; the molar ratio of thiosalicylic acid, benzoyl chloride, sodium bicarbonate and sodium carbonate in every 25-30 mL of water is 1:(0.8-1.5):(2.5-3.2):(1-3); S3. Synthesis of near-infrared fluorescence / photoacoustic dual-response probes Compound A, 4-dimethylaminopyridine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and compound B were prepared in a molar ratio of 1:0.2:(1-2):(3.5-4.5) to obtain a near-infrared fluorescence / photoacoustic dual response probe.

3. The preparation method according to claim 2, characterized in that The specific preparation process of step S1 is: S1.

1. Dissolve 3-hydroxythiophenol and sodium hydride in N,N-dimethylformamide solution, stir at room temperature under nitrogen for 10 to 15 minutes, then add IR-780 iodide, react at 50 to 55°C for 20 to 22 hours, and cool to room temperature after completion of the reaction. Then remove the solvent from the reaction product to obtain a crude product. S1.

2. Using dichloromethane / ethanol as eluent, separate and purify the crude product to obtain compound A.

4. The preparation method according to claim 3, characterized in that In step S1.2, the volume ratio of dichloromethane to ethanol is (40-100):

1.

5. The preparation method according to claim 2, characterized in that The specific preparation process of step S2 is: S2.

1. Dissolve sodium bicarbonate in water to form a sodium bicarbonate solution, then dissolve thiosalicylic acid in the sodium bicarbonate solution and cool to 0°C; then add benzoyl chloride and sodium carbonate, stir at 0°C for 20 to 50 minutes, and then stir at room temperature for another 30 to 60 minutes; S2.

2. After stirring, acidify with concentrated hydrochloric acid until a white precipitate is formed; The precipitate was collected and washed to obtain compound B.

6. The preparation method according to claim 2, characterized in that The specific preparation process of step S3 is: S3.

1. Dissolve compound B, 4-dimethylaminopyridine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide in anhydrous dichloromethane and stir at room temperature for 5 to 25 minutes to obtain a mixed solution. S3.

2. Dissolve compound A in anhydrous dichloromethane and mix well; then add the mixture to the mixed solution described in step S3.1 and stir at room temperature for 5 to 6 hours. After the reaction is complete, extract and evaporate under reduced pressure to obtain a crude product; S3.

3. The crude product is eluted and separated to obtain a near-infrared fluorescence / photoacoustic dual response probe. 7 . The preparation method according to claim 6 , wherein in step S3.3, dichloromethane / methanol is used for elution, and the volume ratio of dichloromethane to methanol is 50:1 to 100:

3.

8. Use of the near-infrared fluorescence / photoacoustic dual response probe as claimed in claim 1 in the quantitative detection of polysulfides.

9. Use of the near-infrared fluorescence / photoacoustic dual response probe as claimed in claim 1 in polysulfide imaging.

10. Use according to claim 8 or 9, characterized in that After the near-infrared fluorescence / photoacoustic dual-response probe reacts with polysulfide, the color is stable within 5 minutes and strong absorption is generated at 740nm to 780nm.

Images