Hemicyanine viscosity detection fluorescent probe as well as preparation method and application thereof

Abstract

The invention discloses a hemicyanine viscosity detection fluorescent probe as well as a preparation method and application thereof. The structural formula of the hemicyanine viscosity detection fluorescent probe is # imgabs0 #. The invention also specifically discloses a preparation method of the hemicyanine viscosity detection fluorescent probe and application of the hemicyanine viscosity detection fluorescent probe in viscosity detection. According to the hemicyanine viscosity detection fluorescent probe prepared by the invention, a DQ (formula IV) structure and a hemicyanine indole salt (formula II) structure are conjugated, so that the photochemical stability can be effectively enhanced, the excitation and emission wavelengths can be increased, and based on free rotation of a C = C double bond between the DQ structure and the hemicyanine indole salt structure, specific and sensitive response to viscosity can be realized; and a potential tool is provided for viscosity detection of the organism microenvironment.

Description

Technical Field

[0001] The invention belongs to the technical field of viscosity detection fluorescent probes, and specifically relates to a semi-cyanine viscosity detection fluorescent probe and a preparation method and application thereof. Background Art

[0002] In living systems, small biomolecules, macromolecules and system microenvironments play an important role in regulating life processes, and their abnormal expression or changes will lead to the occurrence of related diseases. Microenvironment is an important factor affecting the normal physiological activities of cells, and is closely related to cell proliferation, differentiation, metabolism and function. Abnormal changes in the microenvironment can lead to disorders in cell physiological activities, thereby inducing a variety of diseases. The factors that affect the stability of the intracellular microenvironment mainly include viscosity, polarity, temperature, pH, etc. Abnormal changes in any of these factors will affect the stability of the microenvironment, so it is of great significance to detect various parameters of the microenvironment of the organism. Among them, viscosity plays a vital role in the microenvironment of the organism. The viscosity of different regions of the cell varies greatly, so it also affects the diffusion of various regions, such as signal transmission, material transport, and interactions between biochemical substances. However, abnormal viscosity levels are often associated with various diseases, such as cardiovascular disease, diabetes and Alzheimer's disease. Therefore, it is necessary to develop effective tools to detect changes in viscosity in the microenvironment of the organism, which plays an important role in promoting the clinical diagnosis and prevention of diseases. Summary of the invention

[0003] The technical problem solved by the present invention is to provide a semicyanine viscosity detection fluorescent probe and a preparation method thereof. The method uses semicyanine as a matrix to prepare a fluorescent probe with viscosity response performance. The prepared semicyanine viscosity detection fluorescent probe conjugates a DQ (Formula IV) structure with a semicyanine indole salt (Formula II) structure, can effectively enhance its photochemical stability, increase its excitation and emission wavelengths, and achieves specific and sensitive response to viscosity based on the free rotation of the C=C double bond between the two, thereby providing a potential tool for viscosity detection in a biological microenvironment.

[0004] The present invention adopts the following technical solution to solve the above technical problems: a semi-cyanine type viscosity detection fluorescent probe, characterized in that the structure of the fluorescent probe is as shown in Formula I:

[0005]

[0006] The method for preparing the semi-cyanine viscosity detection fluorescent probe of the present invention is characterized by the following specific steps:

[0007] Step S1, adding 4-methoxy-o-phenylenediamine and 1,2-cyclohexanedione into a reaction vessel containing acetonitrile, and then heating the mixture under reflux at 70-80° C. under stirring to obtain a compound of formula III, wherein the structural formula of the compound of formula III is:

[0008]

[0009] Step S2, dissolving the compound represented by formula III in a reaction vessel containing anhydrous toluene, placing the mixture in an ice-water bath and stirring to mix evenly, then adding sodium borohydride in batches to the reaction vessel at 0° C., stirring and mixing the obtained light yellow slurry in an ice bath, then adding anhydrous glacial acetic acid dropwise at 0 to 5° C. and stirring and mixing evenly at room temperature, and heating the mixed system under reflux at 100 to 110° C. to obtain the compound represented by formula IV, wherein the structural formula of the compound represented by formula IV is:

[0010]

[0011] Step S3, adding the compound represented by formula IV to a reaction vessel containing N,N-dimethylformamide, stirring and mixing evenly under ice bath conditions, then adding phosphorus oxychloride dropwise to the reaction vessel, continuing to stir and mix evenly under ice bath conditions, and then stirring the mixed system at room temperature and heating it to 60-80° C. to react to obtain the compound represented by formula V, wherein the structural formula of the compound represented by formula V is:

[0012]

[0013] Step S4, adding the compound represented by formula II, the compound represented by formula V and a catalytic amount of anhydrous sodium acetate into a reaction vessel containing acetic anhydride in sequence, and reacting at 70-80° C. to obtain the compound represented by formula I, wherein the structural formula of the compound represented by formula II is:

[0014]

[0015] Preferably, in step S1, the molar ratio of 4-methoxy-o-phenylenediamine to 1,2-cyclohexanedione is 1:(1.1-1.5).

[0016] Preferably, in step S2, the molar ratio of the compound represented by formula III, sodium borohydride and anhydrous glacial acetic acid is 1:(10-20):(10-20).

[0017] Preferably, in step S3, the molar ratio of the compound represented by formula IV to phosphorus oxychloride is 1:(1.5-2.5).

[0018] Preferably, in step S4, the molar ratio of the compound represented by formula V to the compound represented by formula II is 1:(1-1.5).

[0019] The semi-cyanine viscosity detection fluorescent probe described in the present invention is used in viscosity detection. Under different viscosity environments, the fluorescence intensity of the semi-cyanine viscosity detection fluorescent probe gradually increases with the increase of viscosity, and the fluorescence intensity has a good linear relationship with the viscosity within the physiological range.

[0020] The application of the semi-cyanine viscosity detection fluorescent probe described in the present invention in in vivo viscosity detection has good water solubility and good stability under different pH conditions, and can be applied to complex in vivo viscosity detection. At the same time, the semi-cyanine viscosity detection fluorescent probe has good light stability under different viscosity conditions, and can perform long-term tracing imaging detection of in vivo viscosity changes.

[0021] The semi-cyanine viscosity detection fluorescent probe of the present invention is used in the specific and sensitive detection of viscosity in vivo. The semi-cyanine viscosity detection fluorescent probe has good anti-interference ability under different conditions and is specific for viscosity detection, and can perform specific and sensitive detection of viscosity changes in vivo. At the same time, the semi-cyanine viscosity detection fluorescent probe itself has a longer emission wavelength and a larger Stokes shift, and can be used for viscosity detection in vivo.

[0022] The application of the semi-cyanine viscosity detection fluorescent probe described in the present invention in the preparation of a clinical disease diagnosis tool can realize clinical diagnosis and effective prevention of diseases by using the tool to detect viscosity changes in different regions of cells in a living body. The diseases specifically include cardiovascular diseases, diabetes, Alzheimer's disease, etc.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects: the semi-cyanine viscosity detection fluorescent probe prepared by the present invention has good photochemical stability, the wavelength reaches the near-infrared region, can specifically and sensitively detect viscosity changes in vivo, and has great potential for monitoring changes in the viscosity microenvironment in vivo. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the H NMR spectrum of the compound represented by Formula III in Example 1.

[0025] Figure 2 This is the H NMR spectrum of the compound represented by Formula IV in Example 1.

[0026] Figure 3 This is the H NMR spectrum of the compound represented by Formula V in Example 1.

[0027] Figure 4 It is the H NMR spectrum of the compound represented by Formula I in Example 1.

[0028] Figure 5It is a water-soluble semi-cyanine viscosity detection reagent.

[0029] Figure 6 It is the excitation spectrum of semi-cyanine viscosity detection reagent.

[0030] Figure 7 It is the emission spectrum of semi-cyanine viscosity detection reagent.

[0031] Figure 8 It is the pH stability of semi-cyanine viscosity detection reagents.

[0032] Fig. 9 It is the response spectrum of semi-cyanine viscosity detection reagents at different viscosities.

[0033] Fig.10 It is the linear relationship of the response spectrum of semi-cyanine viscosity detection reagents at different viscosities.

[0034] Fig.11 It is the stability of semi-cyanine viscosity detection reagents at different viscosities.

[0035] Fig.12 It is the anti-interference ability of semi-cyanine viscosity detection reagents under different conditions, including 1-L-cysteine, 2-L-aspartic acid, 3-cystine, 4-DL-threonine, 5-lysine, 6-hypoxanthine, 7-D-methionine, 8-serine, 9-dithiothreitol, 10-glutamic acid, 11-glycine, 12-L-glutamic acid, 13-DL-leucine, 14-arginine, 15-valine, 16-glutamine, 17-glycine-DL-phenylalanine, 18-DL-homocysteine, 19-glycyl-L-tyrosine, 20-SnCl2, 21 -CoCl2, 22-NaCl, 23-KCl, 24-MnSO4, 25-CuSO4, 26-MgSO4, 27-Zn(NO3)2, 28-K2HPO4·3H2O, 29-Ca(NO3)2·4H2O, 30-FeCl3, 31-Li2CO3, 32-FeCl2, 33-bovine serum albumin, 34-DNA, 35-RNA, 36-lipase, 37-β-amylase, 38-trypsin, 39-pepsin, 40-proteinase K, 41-lysozyme, 42-hemoglobin. DETAILED DESCRIPTION

[0036] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0037] Example 1

[0038] The synthesis steps of the semicyanine viscosity detection fluorescent probe are as follows:

[0039] (1) Synthesis of the compound represented by formula III

[0040] 4-Methoxy-o-phenylenediamine (69.1 mg, 0.5 mmol) and 1,2-cyclohexanedione (67.3 mg, 0.6 mmol) were added to a round-bottom flask containing acetonitrile (30 mL), and the mixture was heated to reflux at 70-80°C under stirring conditions and cooled. The solvent was removed in a rotary evaporator, and petroleum ether / dichloroethane (5:1, v / v) was used as an eluent. The crude product was purified by column chromatography to obtain an off-white solid compound, namely the compound shown in Formula III. The H NMR spectrum of the obtained product is shown in Figure 3 shown.

[0041] (2) Synthesis of the compound represented by formula IV

[0042] The compound represented by formula III (1.1 g, 5 mmol) was dissolved in a round-bottom flask containing anhydrous toluene (80 mL), stirred for 30 minutes under ice-water bath conditions, and sodium borohydride (2.8 g, 75 mmol) was added to the round-bottom flask in batches at 0°C within 30 minutes. The obtained light yellow slurry was stirred for 1 hour under ice bath conditions, and then anhydrous glacial acetic acid (4.3 mL, 4.5 g, 75 mmol) was added dropwise to the round-bottom flask at 0-5°C within 1 hour, and then the ice bath was removed, and the obtained slurry was stirred at room temperature for 1 hour, and then heated to reflux at 100-110°C for 6 hours. After cooling, water (80 mL) was added, the organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×100 mL). The combined extract and organic layer were first washed three times with dilute sodium carbonate solution, then washed three times with water, dried over anhydrous sodium sulfate, filtered, and the solvent was removed on a rotary evaporator. The brown oil obtained by concentration was purified by column chromatography using petroleum ether / ethyl acetate (40:1, v / v) as eluent to obtain a yellow oily compound, namely the compound represented by Formula IV. 1 H NMR (600MHz, CDCl3) δ = 6.56 (d, J = 7.2, 1H), 6.28 (d, J = 2.1, 1H), 6.19 (d, J = 7 .5,1H),3.75(s,3H),3.75(s,1H),3.33(m,J=57.2,23.9,16.4,8.3,4H),3. 03–2.90(m,1H),2.85(s,1H),2.23(d,J=11.3,2H),1.81(d,J=8.9,2H),1.3 3(d,J=9.8,2H),1.31–1.17(m,3H),1.12(t,J=7.0,3H),1.07(t,J=6.8,3H). The H NMR spectrum of the obtained product is as follows Figure 2 shown.

[0043] (3) Synthesis of the compound represented by formula V

[0044] The compound shown in formula IV (137.2 mg, 0.5 mmol) was added to a round-bottom flask containing N, N-dimethylformamide (5 mL) and stirred for 30 minutes under ice bath conditions. Phosphorus oxychloride (91.5 μL, 153.3 mg, 1 mmol) was then added dropwise to the round-bottom flask and stirred for 10 minutes under ice bath conditions. The ice bath was removed, and the mixture was stirred at room temperature for 30 minutes and then heated to 70°C for 4 hours. After cooling to room temperature, the reaction solution was poured into an ice-water mixture, and then the solution was neutralized with sodium carbonate, and the water layer was extracted with ethyl acetate (3×100 mL), dried over anhydrous sodium sulfate, filtered, and the solvent was removed by a rotary evaporator. The orange-red oil obtained by concentration was purified by column chromatography using petroleum ether / ethyl acetate (25:1, v / v) as the eluent to obtain an orange solid compound, namely the compound shown in formula V. 1 H NMR (600MHz, CDCl3) δ = 10.11 (s, 1H), 6.99 (s, 1H), 5.99 (s, 1H), 3.81 (s, 3H), 3.57-3.39 (m, 2H), 3.32 (s, 2H), 3.16 (d, J = 40.1, 2H), 1.94 (s, 1H), 1.76 (d, J = 10.4, 1H), 1.63 (dd, J = 9.7, 6.2, 2H), 1.48 (d, J = 9.2, 2H), 1.41-1.28 (m, 2H), 1.20 (t, J = 7.1, 3H), 1.06 (t, J = 7.0, 3H). The hydrogen nuclear magnetic resonance spectrum of the obtained product is shown in Figure 3 shown.

[0045] (4) Synthesis of the compound represented by formula I

[0046] The compound represented by formula V (45.2 mg, 0.15 mmol), the compound represented by formula II (45.4 mg, 0.15 mmol) and anhydrous sodium acetate (8 mg, 0.1 mmol) were added to acetic anhydride (4 mL) in sequence, and the reaction mixture was stirred at 75 ° C for 2 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain a dark green solid, which was purified by column chromatography using dichloromethane / methanol (100:1, v / v) as the eluent to obtain a dark green solid compound, namely the compound represented by formula I. 1H NMR (600MHz, MeOD) δ = 8.41 (s, 1H), 7.54 (d, J = 7.3, 1H), 7.44–7.41 (m, 1H), 7.37 (d, J = 7.9, 1H), 7.2 9(td,J=7.4,0.7,1H),6.95(s,1H),6.13(s,1H),4.75(s,1H),3.99(s,3H),3.78(s,4H),3.65(d,J =8.1, 1H), 3.56 (dd, J = 14.8, 7.3, 1H), 2.10 (d, J = 14.1, 1H), 1.86–1.79 (m, 1H), 1.70 (d, J = 5.1, 7H), 1.68–1.58 (m, 3H), 1.52–1.42 (m, 3H), 1.31 (t, J = 7.1, 3H), 1.25–1.23 (m, 1H), 1.12 (t, J = 6.9, 3H). The H NMR spectrum of the obtained product is shown in Figure 4 shown.

[0047] Example 2

[0048] Water-solubility test of semi-cyanine-based fluorescent probe for viscosity detection

[0049] Take the semi-cyanine viscosity detection fluorescent probe prepared in Example 1 above and prepare it into a DMSO mother solution with a concentration of 6mM. Use a pipette to transfer 1μL of the above mother solution to 3mL of Wahaha pure water, and add it in gradient concentrations each time, stir and fully dissolve it, and ensure that the final volume of DMSO added is less than one thousandth of the total volume. Measure its absorbance value, and the test results are as follows: Figure 5 The results show that the semi-cyanine viscosity detection fluorescent probe has good water solubility and can be used for viscosity detection in vivo, promoting clinical diagnosis and effective prevention of diseases, and thus achieving effective treatment of diseases.

[0050] Example 3

[0051] Experimental study on the excitation and emission spectra of semi-cyanine-based fluorescent probes for viscosity detection

[0052] 5 μL of the semi-cyanine viscosity detection fluorescent probe prepared in Example 1 was added to a four-way cuvette containing 3 mL of different solvents (water, dimethyl sulfoxide, methanol, ethanol, tetrahydrofuran, acetone), and its absorption spectrum was measured by a UV-visible spectrophotometer. The fluorescence spectrum was obtained by collecting the wavelength range of 650-850 nm using the maximum absorption wavelength in the corresponding solvent as the excitation wavelength, and the wavelength corresponding to the strongest fluorescence intensity was the emission wavelength. The results are shown in FIG. Figure 6 and Figure 7The results show that the semi-cyanine viscosity detection fluorescent probe has relatively long excitation and emission wavelengths, which is conducive to detecting viscosity changes in organisms.

[0053] Example 4

[0054] pH stability test of semi-cyanine fluorescent probe for viscosity detection

[0055] Aqueous solutions of different pH values ​​were prepared with concentrated hydrochloric acid and sodium hydroxide, and after being mixed evenly, the fluorescence emission spectrum excited at the maximum absorption wavelength was measured using a fluorescence spectrometer. The pH value was plotted as the horizontal axis and the fluorescence intensity at the maximum emission wavelength as the vertical axis to obtain a pH stability graph. The results are shown in the figure. Figure 8 The results show that the semi-cyanine viscosity detection fluorescent probe can maintain good stability under physiological pH environment, which provides a basis for the specific detection of viscosity in complex biological systems.

[0056] Example 5

[0057] Viscosity response detection test of semi-cyanine viscosity detection fluorescent probe

[0058] High-purity water and glycerol were mixed evenly in different volume ratios to obtain a mixed solution with a volume ratio of glycerol to high-purity water of 0%-100%. 5 μL of the semi-cyanine viscosity detection fluorescent probe prepared in Example 1 was added to 3 mL of the mixed solution in different ratios in a four-way cuvette, and its fluorescence emission spectrum was measured by a fluorescence spectrometer. The results are as follows: Fig. 9 The linear relationship between the fluorescence intensity and viscosity of the semi-cyanine viscosity detection fluorescent probe molecule was obtained by plotting the volume ratio of propylene glycol as the horizontal axis and the Log value of the maximum fluorescence intensity as the vertical axis. The results are shown in Fig.10 The results show that the fluorescence intensity of the semi-cyanine viscosity detection fluorescent probe increases with the increase of viscosity, and the fluorescence intensity has a good linear relationship with viscosity within the physiological range.

[0059] Example 6

[0060] Photostability test of fluorescent probe for viscosity detection of semicyanines

[0061] 5 μL of the semi-cyanine viscosity detection fluorescent probe prepared in Example 1 was added to a 3 mL water and glycerol solution in a four-way cuvette and mixed evenly. The maximum absorption was used as the excitation light to continuously irradiate the test solution for 3 h, and the maximum fluorescence intensity was recorded every 30 s. The photostability spectrum of the semi-cyanine viscosity detection fluorescent probe was obtained with the continuous excitation time as the horizontal axis and the fluorescence intensity as the vertical axis. The results are shown in FIG. Fig.11 The results show that the semicyanine viscosity detection fluorescent probe has good photostability, which is beneficial for long-term monitoring of viscosity changes in organisms.

[0062] Example 7

[0063] Test on the anti-interference ability of semi-cyanine viscosity detection fluorescent probe

[0064] The interferences selected for specific detection include ions, amino acids and macromolecular interferences. Among them, there are 13 ion interferences: SnCl2, CoCl2, NaCl, KCl, MnSO4, CuSO4, MgSO4, Zn(NO3)2, K2HPO4·3H2O, Ca(NO3)2·4H2O, FeCl3, Li2CO3, FeCl2, 18 amino acid interferences: L-cysteine, L-aspartic acid, cystine, DL-threonine, hypoxanthine, D-methionine, serine, dithiothreitol, glutamic acid, glycine, L-glutamic acid, DL-leucine, arginine, valine, glutamine, glycine-DL-phenylalanine, DL-homocysteine, glycyl-L-tyrosine, and 10 macromolecular interferences: bovine serum albumin, DNA, RNA, lipase, β-amylase, trypsin, pepsin, proteinase K, lysozyme, and hemoglobin. 5 μL of the semi-cyanine viscosity detection fluorescent probe prepared in Example 1 was added to 3 mL of PBS solution, and then the above interfering substances were added thereto at a concentration of 20 times the equivalent, and then their fluorescence emission spectra were scanned on a fluorescence spectrometer, and F / F0 was plotted. The results are shown in FIG. Fig.12 The results show that the semi-cyanine viscosity detection fluorescent probe has good selectivity and anti-interference ability for viscosity, and is expected to perform sensitive and specific detection of viscosity changes in organisms.

[0065] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A semi-cyanine viscosity detection fluorescent probe, characterized in that The structure of the fluorescent probe is shown in Formula I:

2. A method for preparing a semicyanine viscosity detection fluorescent probe according to claim 1, characterized in that The specific steps are: Step S1, adding 4-methoxy-o-phenylenediamine and 1,2-cyclohexanedione into a reaction vessel containing acetonitrile, and then heating the mixture under reflux at 70-80° C. under stirring to obtain a compound of formula III, wherein the structural formula of the compound of formula III is: Step S2, dissolving the compound represented by formula III in a reaction vessel containing anhydrous toluene, placing the mixture in an ice-water bath and stirring to mix evenly, then adding sodium borohydride in batches to the reaction vessel at 0° C., stirring and mixing the obtained light yellow slurry in an ice bath, then adding anhydrous glacial acetic acid dropwise at 0 to 5° C. and stirring and mixing evenly at room temperature, and heating the mixed system under reflux at 100 to 110° C. to obtain the compound represented by formula IV, wherein the structural formula of the compound represented by formula IV is: Step S3, adding the compound represented by formula IV to a reaction vessel containing N,N-dimethylformamide, stirring and mixing evenly under ice bath conditions, then adding phosphorus oxychloride dropwise to the reaction vessel, continuing to stir and mix evenly under ice bath conditions, and then stirring the mixed system at room temperature and heating it to 60-80° C. to react to obtain the compound represented by formula V, wherein the structural formula of the compound represented by formula V is: Step S4, adding the compound represented by formula II, the compound represented by formula V and a catalytic amount of anhydrous sodium acetate into a reaction vessel containing acetic anhydride in sequence, and reacting at 70-80° C. to obtain the compound represented by formula I, wherein the structural formula of the compound represented by formula II is:

3. The method for preparing a semicyanine viscosity detection fluorescent probe according to claim 2, characterized in that: In step S1, the molar ratio of 4-methoxy-o-phenylenediamine to 1,2-cyclohexanedione is 1:(1.1-1.5).

4. The method for preparing a semicyanine viscosity detection fluorescent probe according to claim 2, characterized in that: In step S2, the molar ratio of the compound represented by formula III, sodium borohydride and anhydrous glacial acetic acid is 1:(10-20):(10-20).

5. The method for preparing a semicyanine viscosity detection fluorescent probe according to claim 2, characterized in that: In step S3, the molar ratio of the compound represented by formula IV to phosphorus oxychloride is 1:(1.5-2.5).

6. The method for preparing a semicyanine viscosity detection fluorescent probe according to claim 2, characterized in that: In step S4, the molar ratio of the compound represented by formula V to the compound represented by formula II is 1:(1-1.5).

7. Use of the semi-cyanine viscosity detection fluorescent probe according to claim 1 in viscosity detection, wherein the fluorescence intensity of the semi-cyanine viscosity detection fluorescent probe gradually increases with the increase of viscosity under different viscosity environments, and the fluorescence intensity has a good linear relationship with the viscosity within the physiological range.

8. Application of the semi-cyanine viscosity detection fluorescent probe according to claim 1 in in vivo viscosity detection, the semi-cyanine viscosity detection fluorescent probe has good water solubility and good stability under different pH conditions, and can be applied to complex in vivo viscosity detection. At the same time, the semi-cyanine viscosity detection fluorescent probe has good light stability under different viscosity conditions, and can perform long-term tracing imaging detection of in vivo viscosity changes.

9. Application of the semicyanine viscosity detection fluorescent probe according to claim 1 in specific and sensitive detection of viscosity in vivo, wherein the semicyanine viscosity detection fluorescent probe has good anti-interference ability under different conditions and is specific for viscosity detection, and can perform specific and sensitive detection of viscosity changes in vivo. Meanwhile, the semicyanine viscosity detection fluorescent probe itself has a longer emission wavelength and a larger Stokes shift, and can be used for viscosity detection in vivo.

10. Use of the semi-cyanine viscosity detection fluorescent probe according to claim 1 in the preparation of a clinical disease diagnosis tool, by using the tool to detect viscosity changes in different regions of cells in a living body to achieve clinical diagnosis and effective prevention of the disease.

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