Visible light long-wavelength activated optical switch molecule as well as synthesis method and application thereof

Abstract

The invention belongs to the technical field of optical switch molecular materials, and particularly relates to a visible light long-wavelength activated optical switch molecule and a synthesis method and application thereof. The optical switch molecule disclosed by the invention is an optical switch molecule based on a rhodamine parent nucleus; the synthesis method comprises the following steps: carrying out condensation reaction, coupling reaction, substitution reaction or Click reaction on an intermediate fluorophore and 1, 4-oxathiacyclohexene to prepare the optical switch molecule; the photoactivated molecule designed and synthesized by the invention can be gradually lightened and then subjected to a photobleaching process in an exciting light irradiation process, so that the photoactivated molecule is suitable for long-time tracing and can be used for super-resolution imaging of cells, including living cells and dead cells. The photoswitch molecule can realize photoactivation through long-wavelength irradiation, and can be widely applied to the field of photochemistry.

Description

Technical Field

[0001] The invention belongs to the technical field of optical switch molecular materials, and in particular relates to a long-wavelength activated optical switch molecule and a synthesis method and application thereof. Background Art

[0002] Photoactivated fluorescent probes, also known as light-lit fluorescent probes, are widely used in the fields of optical devices and molecular imaging. Traditional photocage groups such as azide, o-nitrobenzyl, nitroso and tetrazine mostly require short-wavelength ultraviolet light to decompose or leave. Ultraviolet light has low penetration in cell tissues and is easily absorbed, causing background fluorescence interference. Xiao's team converted the carbonyl group in the fluorophore into a thiocarbonyl group using Lawesson's reagent. In the visible light range, the thiocarbonyl group is oxidized to an oxycarbonyl group by the singlet oxygen generated in the molecule to achieve visible light activation, but this method has the particularity of the molecule and requires the fluorophore itself to contain a carbonyl structure. Therefore, it is particularly important to develop a universal photocage group and a fluorescent dye that can be photoactivated by long-wavelength irradiation.

[0003] The document Chem. Commun. 2003, 1756-1757 reports a 1,4-oxathiin compound that can bind to singlet oxygen to break the double bond.

[0004]

[0005] Patent CN 112457336 A combines 1,4-oxathiinyl with BODIPY, and achieves fast photolysis speed and high photolysis efficiency through the singlet oxygen generated by the photosensitizer, which is applied to long afterglow luminescent materials in fields that require rapid light activation.

[0006]

[0007] However, so far, there are no compounds that combine 1,4-oxathiacyclohexene with cyanine, rhodamine and coumarin dye molecules. And there are few reports on the oxidation of the photocage group 1,4-oxathiacyclohexene by generating singlet oxygen after absorbing photons to achieve visible light photoactivation. Summary of the invention

[0008] The purpose of the present invention is to provide a long-wavelength visible light activated optical switch molecule and a synthesis method and application thereof.

[0009] The light switch molecule activated by long wavelength visible light provided by the present invention is a universal light switch molecule based on coumarin, rhodamine and cyanine nuclei, and realizes the strategy of light activation by long wavelength irradiation and its application in the field of photochemistry. The light switch molecule has the molecular structure shown in I, II or III below:

[0010]

[0011] Where:

[0012] A is selected from oxygen or dimethylsilyl;

[0013] n is selected from the integers 1, 3 or 5;

[0014] LK is a functional group or chemical bond that connects the upper 1,4-cyclohexene structure and the lower fluorophore structure;

[0015] The linking functional group is selected from any one of the following:

[0016]

[0017] R 1 , R 2 may be the same or different and are selected from oxygen, sulfur, nitrogen or carbon;

[0018] R 3 , R 4 may be the same or different, and are selected from hydrogen, an alkyl group having 1 to 50 carbon atoms, an alkoxy group having 1 to 50 carbon atoms, and an alkylamino group having 1 to 50 carbon atoms;

[0019] R 5 , R 6 may be the same or different, and are selected from hydrogen, C 1 -C 12 Alkyl, C 1 -C 12 Alkoxy, C 3 -C 12 Cycloalkyl, C 1 -C 12 Alkylamino, C 1 -C 12 Alkylthio, C 2 -C 12 Alkenyl, C 2 -C 12 Alkynyl, C 2 -C 12 Alkenyloxy, C 2 -C 12 Alkynyloxy, C 1 -C 12 Alkyl sulfonic acid group, C 1 -C 12 Alkyl carboxyl; R 7 , R 8 may be the same or different, and are selected from hydrogen, sulfonic acid, phosphoric acid, and carboxyl;

[0020] R 9 , R 10 may be the same or different, and are selected from hydrogen, C1 -C 12 Alkyl, C 1 -C 12 Alkoxy, C 3 -C 12 Cycloalkyl, C 1 -C 12 Alkylamino, C 1 -C 12 Alkylthio, C 2 -C 12 Alkenyl, C 2 -C 12 Alkynyl, C 2 -C 12 Alkenyloxy, C 2 -C 12 Alkynyloxy, C 1 -C 12 Alkyl sulfonic acid group, C 1 -C 12 Alkyl carboxyl;

[0021] R 11 , R 12 may be the same or different and are independently selected from hydrogen, alkyl, alkoxy, alkylamino, alkylcyano, aryl or benzaryl having 1 to 16 carbon atoms;

[0022] wherein the aryl group has no substituent group or is substituted by one or more groups L;

[0023] L is selected from an alkoxy group, a hydroxyl group, a carboxyl group, an amino group, an ester group, a nitro group or a sulfonic acid group.

[0024] According to one embodiment of the present invention, the optical switch molecule is any one of the following compounds:

[0025]

[0026]

[0027]

[0028] The present invention also provides a method for synthesizing the above-mentioned optical switch molecule, comprising: preparing the optical switch molecule through a condensation reaction, a coupling reaction, a substitution reaction or a Click reaction of an intermediate fluorophore and 1,4-oxathiin; the synthesis route is:

[0029]

[0030] in:

[0031] The condensation reaction comprises the following specific steps:

[0032] The fluorophore and 1,4-oxathiin are added to an organic solvent, and a condensation agent is added, wherein the molar ratio of the fluorophore, 1,4-oxathiin and the condensation agent is 1:1:1, and the reaction is carried out for 12 to 24 hours to obtain a target solution, and a light switch molecule is obtained after post-treatment.

[0033] The condensing agent is selected from one of dicyclohexylcarbodiimide (DCC), 1-ethyl-3 (3-dimethylpropylamine) carbodiimide (EDCI), 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), benzotriazole (HOBt) and 1-ethyl-3 (3-dimethylpropylamine) carbodiimide (EDCI).

[0034] The coupling reaction (including Suzuki coupling, Heck coupling, Sonogoshira coupling) comprises the following specific steps:

[0035] Add the fluorophore and 1,4-oxathiin to an organic solvent, add a coupling reaction catalyst and a base, the molar ratio of the fluorophore, 1,4-oxathiin, the catalyst and the base is 1:1:0.01:3 to 1:1:0.1:8 (1:1:(0.01 to 0.1):(3 to 8)), preferably 1:1:0.05:5, react for 8 to 24 hours to obtain a target solution, and obtain a light switch molecule after post-treatment.

[0036] The catalyst is selected from palladium chloride, palladium acetate or tetrakis(triphenylphosphine)palladium.

[0037] The substitution reaction comprises the following specific steps:

[0038] Add the fluorophore and 1,4-oxathiin to an organic solvent, add a base, the molar ratio of the fluorophore, 1,4-oxathiin and the base is 1:1:3 to 1:1:10 (1:1:(3 to 10)), preferably 1:1:5, react for 12 to 24 hours to obtain a target solution, and obtain a light switch molecule after post-treatment.

[0039] The Click reaction comprises the following specific steps:

[0040] Add a fluorophore and 1,4-oxathiin to an organic solvent, add a Click reaction catalyst, the molar ratio of the fluorophore, 1,4-oxathiin and the Click reaction catalyst is 1:1:0.01 to 1:1:0.09 (1:1:(0.01 to 0.09)), preferably 1:1:0.05, react for 12 to 24 hours to obtain a target solution, and obtain the optical switch molecule after post-treatment.

[0041] The catalyst is selected from one of copper sulfate and cuprous iodide.

[0042] In the above reactions, the organic solvent is one or a mixture of toluene, tetrahydrofuran, 1,4-dioxane, ethanol, methanol, N,N-dimethylformamide or dimethyl sulfoxide.

[0043] In the above synthesis method, the intermediate fluorophore is selected from any one of the following compounds:

[0044]

[0045]

[0046] The 1,4-oxathiin is selected from any one of the following compounds:

[0047]

[0048] Traditional fluorescent molecules will suffer from severe photobleaching when used in cell imaging, so long-term tracking cannot be achieved. The photoactivated molecules designed and synthesized in the present invention will undergo a process of gradual lighting and then photobleaching during the process of excitation light irradiation, so they are suitable for long-term tracking.

[0049] The photoactivated fluorescent molecules of the present invention can be used for super-resolution imaging of cells, including living cells and dead cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the H NMR spectrum of Cy5-SO in Example 2 in deuterated methanol.

[0051] Figure 2 This is the carbon NMR spectrum of Cy5-SO in Example 2 in deuterated methanol.

[0052] Figure 3 This is the H NMR spectrum of Coumarin-SO of Example 3 in deuterated chloroform.

[0053] Figure 4 This is the carbon NMR spectrum of Coumarin-SO of Example 3 in deuterated chloroform.

[0054] Figure 5 This is the H NMR spectrum of Rhodamine-SO of Example 1 in deuterated chloroform.

[0055] Figure 6 This is the carbon NMR spectrum of Rhodamine-SO in deuterated chloroform of Example 1.

[0056] Figure 7The photoactivation process of Cy5-SO (10 μM) in pH 7.4 PBS phosphate buffer of Example 2 was performed by irradiating with 405 nm (a), 473 nm (b), 532 nm (c), and 635 nm (d) lasers for 2 h (power density 35 W / cm 2 ), the emission spectra were measured after the times indicated in the figures.

[0057] Figure 8 The photoactivation process of Rhodamine-SO (50 μM) in pH 7.4 PBS phosphate buffer of Example 1 was performed by irradiating with 405 nm (a), 473 nm (b), 532 nm (c), and 635 nm (d) lasers for 2 hours (power density 35 W / cm 2 ), the emission spectra were measured after the times indicated in the figures.

[0058] Fig. 9 The photoactivation process of Coumarin-SO (10 μM) in DMSO of Example 3 was performed by irradiating with 405 nm (a), 473 nm (b), 532 nm (c), and 635 nm (d) lasers for 2 hours (power density 35 W / cm 2 ), the emission spectra were measured after the times indicated in the figures.

[0059] Fig.10 The photoactivation process of Cy3-SO (10 μM) in DMSO of Example 4 was performed by irradiating with 405 nm (a), 473 nm (b), 532 nm (c), and 635 nm (d) lasers for 2 hours (power density 35 W / cm 2 ), the emission spectra were measured after the times indicated in the figures.

[0060] Fig.11 This is the photoactivated cell imaging of Example 6, which is a graph of the photoactivation and photobleaching process of Cy5-SO in Hela cells under 635nm laser irradiation and its fluorescence intensity change.

[0061] Fig.12 This is the photoactivated cell imaging of Example 6, which is a graph of the photoactivation and photobleaching process of Rhodamine-SO in Hela cells under 532nm laser irradiation and its fluorescence intensity change.

[0062] Fig.13 This is the photoactivated cell imaging of Example 6, which is a graph of the photoactivation and photobleaching process of Coumarin-SO in Hela cells under 405 nm laser irradiation and its fluorescence intensity change.

[0063] Fig.14This is Example 7: Rhodamine-SO-PA is used for super-resolution imaging of fixed DRG neurons. (a) Comparison of traditional wide-field and single-molecule localization super-resolution images. (b) FWHM analysis of microtubules in the yellow box in (a). (c) Periodic analysis of DRG neurons. DETAILED DESCRIPTION

[0064] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0065] Example 1: Preparation of rhodamine-SO

[0066]

[0067] Rhodamine-Br (47 mg, 0.1 mmol, 1 eq), borate (64 mg, 0.15 mmol, 1.5 eq), tetrakistriphenylphosphine palladium (5.8 mg, 0.005 mmol, 0.05 eq) and sodium carbonate (42 mg, 0.4 mmol, 4 eq) were added to a 25 mL three-necked flask in sequence. Then 1,4-dioxane / ethanol / water (10 mL, 4:1:1) was added to the reaction mixture, and the mixture was refluxed and stirred at 100 ° C under nitrogen protection overnight. The reaction was cooled to room temperature and the solvent was removed under reduced pressure. Purification by silica gel column chromatography (eluent: dichloromethane / methanol = 20:1) gave 41 mg of brown solid with a yield of 60%. The product was subjected to 1 H NMR, 13 C NMR and MS confirmed: 1 HNMR (400MHz, CDCl 3 )δ7.97(d,J=7.8Hz,1H),7.72(d,J=7.8Hz,1H),7.25-7.23(m,4H),7.16(s,1H),7.04(d,J=8.3Hz,2H),6.64(d ,J=8.3Hz,2H),6.55–6.45(m,4H),6.37(d,J=7.3Hz,2H),4.46(s,2H),3.19(s,2H),2.95(s,12H),2.87(s,6H). 13 C NMR (101 MHz, CDCl 3)δ169.8,154.4,152.9,152.0,149.7,147.5,143.9,137.5,137.1,130.9,129.2,128.9,128.2,126. 5,126.1,125.9,125.0,122.0,112.2,109.4,108.7,106.9,98.6,65.6,40.3,40.3,28.5; HR-ESI-MS m / z:[M+H] + calcd.for C 42 H 40 N 3 O 4 S + ,682.2734;found,682.2733.

[0068] Example 2. Preparation of Cy5-SO

[0069]

[0070] Cy5-Br (64 mg, 0.1 mmol, 1 eq), borate (64 mg, 0.15 mmol, 1.5 eq), tetrakistriphenylphosphine palladium (5.8 mg, 0.005 mmol, 0.05 eq) and sodium carbonate (42 mg, 0.4 mmol, 4 eq) were added to a 25 mL three-necked flask in sequence. Then 1,4-dioxane / ethanol / water (10 mL, 4:1:1) was added to the reaction mixture, and the mixture was refluxed at 100 °C with nitrogen protection and stirred for 3 hours. The reaction was cooled to room temperature and the solvent was removed under reduced pressure. Purification by silica gel column chromatography (eluent: dichloromethane / methanol = 15:1) gave 58 mg of brown solid with a yield of 68%. The product was subjected to 1 H NMR, 13 C NMR and MS confirmed: 1 H NMR (400 MHz, CDCl 3 )δ8.22-8.17(m,2H),7.45–7.31(m,6H),7.24-7.10(m,6H),7.04(d,J=7.7Hz,2H),6.58(d,J=8.2Hz,2H),5. 71–5.58(m,2H),4.55(s,2H),3.77(s,4H),3.25(s,2H),2.92(s,6H),2.37(s,2H),1.93–1.73(m,12H),1.66 -1.56(m,4H),1.22(s,3H). 13 C NMR (101 MHz, CDCl 3)δ175.8,173.2,172.7,153.0,149.7,144.1,141.8,141.4,141.4,141 .2,136.7,135.0,133.7,131.0,129.6,129.3,128.7,128.7,126.5,125 .5,122.6,122.4,112.3,110.8,110.4,109.4,101.6,101.2,65.7,49.6 ,44.2,40.6,39.2,33.9,28.6,28.2,28.1,26.6,22.3,12.1; HR-ESI-MS m / z:[M+H] + calcd.for C 50 H 56 N 3 O 3 S + ,778.4037;found,778.4034.

[0071] Example 3, preparation of coumarin-SO

[0072]

[0073] In a 25mL three-necked flask, coumarin-Br (42mg, 0.1mmol, 1eq), borate (64mg, 0.15mmol, 1.5eq), tetrakistriphenylphosphine palladium (5.8mg, 0.005mmol, 0.05eq) and sodium carbonate (42mg, 0.4mmol, 4eq) were added in sequence. Then 1,4-dioxane / ethanol / water (10mL, 4:1:1) was added to the reaction mixture and stirred at 90°C for 12 hours under nitrogen protection. The reaction was cooled to room temperature and the solvent was removed under reduced pressure. Purification by silica gel column chromatography (eluent: dichloromethane / methanol / tetrahydrofuran = 100:1:1) gave 28mg of a yellow solid with a yield of 45%. The product was subjected to 1 H NMR, 13 C NMR and MS confirmed: 1 H NMR (400 MHz, CDCl 3)δ8.04(d,J=7.9Hz,2H),7.38(d,J=8.9Hz,1H),7.27(d,J=7.9Hz,2H),7.23(d,J=8.1Hz,2H),7.12(d,J=8.9Hz,2H),7.04(d,J=8.1Hz,2H) ,6.70–6.41(m,4H),4.63(s,2H),4.49(s,2H),3.55(d,J=6.9Hz,2H),3.29–3.11(m,2H),2.89(s,6H),2.12(s,3H),1.26(t,J=6.9Hz,3H). 13 C NMR (101 MHz, CDCl 3 )δ171.4,161.7,154.8,150.6,149.7,148.2,144.5,144.2,136.1,133.6,130.9,130.8,129.8,128.5,12 6.4,126.2,121.7,112.4,110.6,109.1,108.6,98.3,65.6,53.9,46.1,40.5,28.5,16.3,12.2; HR-ESI-MS m / z:[M+H] + calcd.for C 38 H 37 N 2 O 5 S + ,633.2418;found,633.2393.

[0074] Example 4: Preparation of Cy3-SO

[0075]

[0076] Cy3-Br (59 mg, 0.1 mmol, 1 eq), borate (64 mg, 0.15 mmol, 1.5 eq), tetrakistriphenylphosphine palladium (5.8 mg, 0.005 mmol, 0.05 eq) and sodium carbonate (42 mg, 0.4 mmol, 4 eq) were added to a 25 mL three-necked flask in sequence. Then 1,4-dioxane / ethanol / water (10 mL, 4:1:1) was added to the reaction mixture and stirred at 100 °C for 12 hours under nitrogen protection. The reaction was cooled to room temperature and the solvent was removed under reduced pressure. Purification by silica gel column chromatography (eluent: dichloromethane / methanol = 20:1) gave 53 mg of a yellow solid with a yield of 65%. The product was subjected to 1 H NMR, 13 C NMR and MS confirmed: 1 H NMR (400 MHz, CDCl 3)δ8.47-8.41(m,1H),7.57(d,J=7.8Hz,1H),7.51(s,1H),7.43–7.35(m,6H),7.29(t,J=8.2Hz,3H),7.15(d,J=7.8Hz,4H), 6.61(d,J=8.2Hz,2H),4.54(s,2H),4.34(q,J=6.6Hz,4H),3.25(s,2H),2.94(s,6H),1.73(s,12H),1.52(t,J=6.6Hz,6H). 13 C NMR (101 MHz, CDCl 3 )δ173.1,172.8,150.4,149.6,144.1,141.7,141.3,140.9,140.7,138.3,138.1,136.2,130.9,129.9,129.3,128.9,127.6,126.1,12 5.9,125.3,125.1,122.2,120.6,112.2,110.9,110.8,108.9,104.5,65.6,48.9,40.4,40.2,40.1,28.5,28.1,28.1,13.0; HR-ESI-MS m / z:[M]calcd.for C 45 H 50 N 3 OS + ,680.3669;found,680.3665.

[0077] Example 5: Compound photoswitch activity test

[0078] Cy5-SO, Rhodamine-SO, Coumarin-SO and Cy3-SO fluorescent dyes were irradiated with 405nm, 473nm, 532nm and 635nm lasers, respectively, and the fluorescence spectra at different irradiation time points were tested ( Figure 7-10 ). Experimental results show that 1,4-oxathiinyl (SO) combined with cyanine, rhodamine and coumarin dye molecules can be photoactivated by visible light through long-wavelength irradiation. Cy5-SO, Rhodamine-SO and Coumarin-SO were all observed to have significant fluorescence enhancement under light irradiation within their absorption spectra ( Figure 7-9 After irradiation with 405nm, 473nm, 532nm and 635nm laser for 2 hours, the fluorescence intensity of Cy5-SO increased by 8 times, 5 times, 7 times and 6 times respectively ( Figure 7After irradiation with 405nm, 473nm and 532nm laser for 2 hours, the fluorescence intensity of Rhodamine-SO increased by 81 times, 37 times and 61 times respectively. When irradiated with 635nm laser outside the absorption spectrum, only a weak fluorescence enhancement was observed ( Figure 8 The fluorescence intensity of Coumarin-SO increased by 34 times when irradiated with 405nm laser for 2 hours. There was no obvious fluorescence enhancement when irradiated with 473nm, 532nm and 635nm laser for 2 hours outside the absorption spectrum. Fig. 9 In addition, since the SO group in Cy3-SO is located at the indole position of Cy3, the molecule itself has poor photostability, and no significant fluorescence enhancement was observed under light irradiation within its absorption spectrum, and a weak fluorescence enhancement was observed under 405nm light ( Fig.10 ).

[0079] Example 6: Photoactivated Cell Imaging

[0080] To study the photoswitch activity of photoactivated fluorescent probes in cells, confocal laser scanning microscopy was used to perform photoactivated imaging experiments on HeLa cells ( Figure 11-13 ). Hela cells were incubated with 10 micromolar fluorescent probes (Cy5-SO, Rhodamine-SO and Coumarin-SO dissolved in pH 7.4 PBS buffer solution, respectively) at 37°C in the dark for 30 minutes. The intracellular fluorescent probes were photoactivated by confocal laser scanning microscopy to explore the relationship between the intracellular fluorescence intensity and the excitation light irradiation time. The excitation wavelengths of Cy5-SO, Rhodamine-SO and Coumarin-SO were 637nm, 561nm and 405nm, respectively, and the excitation powers were 31μW, 70μW and 15μW, respectively. Under the continuous scanning of the laser, continuous fluorescence enhancement was observed. Since the probes will undergo photobleaching after photoactivation, the fluorescence intensity will continue to decrease after reaching the peak value, and the fluorescence intensity shows a trend of increasing first and then decreasing, which confirms that SO-type photoactivated fluorescent probes can achieve visible light long-wavelength photoactivation in living cells.

[0081] Example 7: Photoactivated super-resolution imaging

[0082] In order to further explore the excellent photoactivation performance and application prospects of photoactivated fluorescent probes, the present invention modified the molecular structure of Rhodamine-SO and attached a docetaxel group targeting microtubules (Rhodamine-SO-PA) to perform microtubule super-resolution imaging in fixed DRG neurons ( Fig.14 DRG neuron samples cultured in vitro for 9 days were fixed with glutaraldehyde and incubated with 2 μM Rhodamine-SO-PA at room temperature in the dark for 60 min.2 The sample was excited by a 532nm laser and subjected to PALM super-resolution imaging. The acquired data set was processed with the ThorenderSTORM software to reconstruct a super-resolution image that exceeded the diffraction limit and showed a more detailed structure of the microtubules. Compared with the 347nm half-width of the microtubules obtained by traditional wide-field imaging, the reconstructed super-resolution image showed a half-width of 66.9nm. The reconstructed super-resolution image also showed the periodic distribution of tubulin along the axon of about 150nm.

Claims

1. A photoswitch molecule activated by long wavelength visible light, It is characterized in that It is a photo-switch molecule based on the rhodamine core, and its molecular structure is any of the following:

2. A method for synthesizing a photoswitch molecule activated by long wavelength visible light as claimed in claim 1, It is characterized in that include: The intermediate fluorophore and 1,4-oxathiin are reacted by condensation reaction, coupling reaction, substitution reaction or Click reaction to prepare a light switch molecule; wherein: The condensation reaction comprises the following specific steps: Adding a fluorophore and 1,4-oxathiin to an organic solvent, adding a condensing agent, wherein the molar ratio of the fluorophore, 1,4-oxathiin to the condensing agent is 1:1:1, reacting for 12 to 24 hours to obtain a target solution, and post-treating to obtain a light switch molecule; the condensing agent is selected from one of dicyclohexylcarbodiimide (DCC), 1-ethyl-3 (3-dimethylpropylamine) carbodiimide (EDCI), 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU) or benzotriazole (HOBt) and 1-ethyl-3 (3-dimethylpropylamine) carbodiimide (EDCI); The coupling reaction comprises the following specific steps: Adding a fluorophore and 1,4-oxathiin to an organic solvent, adding a coupling reaction catalyst and a base, wherein the molar ratio of the fluorophore, 1,4-oxathiin, the catalyst and the base is 1:1:0.01:3 to 1:1:0.1:8, reacting for 8 to 24 hours to obtain a target solution, and post-processing to obtain a light switch molecule; wherein the catalyst is selected from palladium chloride, palladium acetate or tetrakis(triphenylphosphine)palladium; The substitution reaction comprises the following specific steps: Adding a fluorophore and 1,4-oxathiin to an organic solvent, adding a base, wherein the molar ratio of the fluorophore, 1,4-oxathiin and the base is 1:1:3 to 1:1:10, reacting for 12 to 24 hours to obtain a target solution, and obtaining a light switch molecule through post-treatment; The Click reaction comprises the following specific steps: Add a fluorophore and 1,4-oxathiin to an organic solvent, add a Click reaction catalyst, the molar ratio of the fluorophore, 1,4-oxathiin and the Click reaction catalyst is 1:1:0.01 to 1:1:0.09, react for 12 to 24 hours to obtain a target solution, and obtain the optical switch molecule after post-treatment; the catalyst is one of copper sulfate or cuprous iodide.

3. The synthesis method according to claim 2, It is characterized in that In the above reactions, the organic solvent is one or a mixture of toluene, tetrahydrofuran, 1,4-dioxane, ethanol, methanol, N,N-dimethylformamide or dimethyl sulfoxide.

4. The synthesis method according to claim 2, It is characterized in that The intermediate fluorophore is selected from any one of the following compounds:

5. The synthesis method according to claim 2, It is characterized in that The 1,4-oxathiin is selected from any one of the following compounds:

6. Use of the photoswitch molecule activated by long wavelength visible light as claimed in claim 1 in the preparation of a cell imaging agent.

Images