Amide cyanine dye, synthesis method therefor and use thereof in fluorescence imaging

Abstract

The present invention relates to the technical fields of fluorescent dye synthesis, fluorescence imaging, and bio-sensing. Disclosed are an amide cyanine dye, an efficient synthesis method therefor, and a use thereof in fluorescence imaging. Compared with traditional cyanine dye synthesis methods, the amide cyanine dye synthesis method of the present invention is simple and has few by-products, short reaction time, high yield, a stable structure, and high universal applicability. By increasing the length of a conjugated chain, the absorption and emission wavelengths of the amide cyanine dye can be expanded from a short-wave near-infrared region to a near-infrared-II band. Experiments have proven that the amide cyanine dye has good photophysical properties and the potential for biofluorescence imaging, and can be used in biometric imaging, super-resolution fluorescence imaging of cellular mitochondria, protein labeling, specific recognition of antibodies, nucleic acid labeling, DNA sequencing, tumor photodynamic therapy, etc. On the basis of the advantages, the amide cyanine dye of the present invention has good prospects for application in the field of biofluorescence imaging research.

Description

An amide cyanine dye, a synthesis method thereof and a fluorescent imaging application thereof TECHNICAL FIELD

[0001] The present application belongs to the field of fluorescent dye synthesis, fluorescent imaging and biosensing, and relates to an amide cyanine dye, a synthesis method thereof and an application thereof in the field of biological fluorescent imaging. BACKGROUND

[0002] Cyanine dyes have a long history. The special conjugated structure makes them have good optical properties. In the early stage, they were often used in photographic sensitizers, solar cells and optical disc storage. In recent years, they have been developed for cell imaging, nucleic acid probes, ion probes, photodynamic therapy (PDT), targeted drug carriers and other biomedical fields. Cyanine dyes have high molar extinction coefficient, adjustable absorption / emission spectrum, strong structure modification, and the fluorescence range can reach the near-infrared region with the extension of the conjugated chain, which can effectively avoid background fluorescence interference, making them have great potential to become a good biological fluorescent probe. Cyanine dye molecules contain n methine groups (called methine chains), and the length of the methine chain, the heterocyclic structure, the nature and position of the substituent group will all affect the photophysical properties of the cyanine dye. Among them, the methine chain is the main structural factor that determines the spectral properties of the cyanine dye fluorophore. Studies have shown that the functionalization of the methine chain can significantly improve the stability of the dye and change its photophysical properties and biological selectivity. Therefore, more and more research has focused on the modification of the methine chain, and its design and construction have always been a hot and difficult topic. In addition, the synthesis process of cyanine dyes is complex, the reaction time is long, there are many by-products, and it is extremely difficult to separate and purify. These shortcomings have caused the cyanine dyes sold on the market to be high in price and low in purity. Therefore, it is of great significance to develop a synthesis method of cyanine dyes that is not only simple in steps, short in reaction time, high in yield, stable in structure, and high in universality, but also can extend the length of the conjugated chain by growing the methine chain. SUMMARY

[0003] In order to overcome the defects of the existing synthesis of cyanine dyes, the present application innovatively proposes a high-efficiency synthesis method of amide cyanine dyes. The synthesis method of amide cyanine dyes not only has simple steps, fast reaction speed, high yield, stable structure, high universality, but also has strong structure modification, can extend the length of the conjugated chain by growing the methine chain, and extend the absorption wavelength and fluorescence emission wavelength to the near-infrared region. It overcomes the limitations of many existing synthesis methods of cyanine dyes, and its application in cell imaging and biosensing, especially in stimulated emission depletion (STED) imaging of cell mitochondria. The amide cyanine dye prepared by the present application includes but is not limited to the structure shown in general formula I.

[0004] The present application provides an amide cyanine dye, which has the structure shown in formula I.

[0005] In formula I,

[0006] n is selected from 0, 1, 2 and 3;

[0007] R1 is selected from one of hydrogen, alkyl, phenyl; preferably, R1 is selected from hydrogen, methyl, or phenyl;

[0008] R2 is selected from a heteroatom-containing polycyclic ring, wherein the heteroatom is selected from N, O, S, Se, etc., and the methyl is connected to the heteroatom-containing polycyclic ring; preferably, R2 is selected from the following structures:

[0009] Further preferably, the amide cyanine dye according to the present application comprises the following compound:

[0010] The present application also provides a synthesis method of the amide cyanine dye, which comprises the following steps:

[0011] The methyl compound and the aldehyde oxazole compound with high reactivity are added to an organic solvent, and then a base is added or not added, and then the reaction is carried out to obtain the amide cyanine dye with the structure of formula I, and the reaction process of the synthesis method is shown in the following reaction formula (a):

[0012] In the reaction formula (a), n, R1 and R2 are defined as in formula I.

[0013] The temperature of the reaction is -10℃ to 80℃; preferably, 25℃.

[0014] The reaction time is 1min to 120min; preferably, 5min.

[0015] The base can be selected to be added or not added, and if the base is added, the reaction time is shortened to 1min.

[0016] The base is selected from an organic base or an inorganic base, wherein the inorganic base is selected from any one of sodium hydroxide, potassium hydroxide, potassium carbonate, cesium carbonate, sodium acetate, sodium ethoxide, etc.; the organic base is selected from one of triethylamine, piperidine and diisopropyl ethylamine, etc.; preferably, sodium acetate.

[0017] The organic solvent is selected from one or a combination of several of methanol, ethanol, propanol, acetonitrile or N,N-dimethylformamide DMF, etc.; preferably, ethanol.

[0018] The molar ratio of the methyl compound, the aldehyde-based oxazole compound and the base with high reactivity is 2-5:1:0-2; preferably, 2:1:1.

[0019] The reaction principle involved in the method in the application is twice nucleophilic addition reaction, and the reaction mechanism is as follows:

[0020] The preparation method in the application is compared with the method in the prior art

[0021] The application further provides application of the amide cyanine dye in in-vitro and / or cell imaging and biosensing, wherein the application includes application of the amide cyanine dye in cell imaging, protein labeling, specific recognition of antibodies, nucleic acid labeling, fluorescent probes, DNA sequencing and tumor photodynamic therapy.

[0022] In addition, compared with the traditional cyanine dye synthesis method, the synthesis method of the amide cyanine dye in the application not only has simple steps, fast reaction speed, high yield, stable structure, high universality, but also has strong structure modifiability, can expand the length of the methine chain to increase the conjugated chain, and overcomes the limitation of many existing cyanine dye synthesis methods. In the application, the amide cyanine dye compound has a very broad application prospect in the field of fluorescent dyes and biological fluorescence imaging research.

[0023] In one specific embodiment of the application, the synthesis method of the amide cyanine dye comprises:

[0024] The methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(8)), 4-aldehyde-based oxazole (including but not limited to the structure shown in reaction formula (a)) is added to ethanol, then sodium acetate is added, and the reaction is carried out at room temperature for 5 min to obtain a crude product. The crude product is directly filtered with diatomite to remove sodium acetate, without other purification methods. The filtrate is evaporated under reduced pressure to remove the solvent, to obtain the amide cyanine dye, with a yield of 99%.

[0025] In one specific embodiment of the application, the synthesis method of the amide cyanine dye with strong structure modifiability and capable of expanding the length of the methine chain to increase the conjugated chain can extend the absorption wavelength and the fluorescence emission wavelength to the near-infrared two-band wavelength range, including:

[0026] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0027] The application further provides application of the amide phthalocyanine dye in cell imaging and biosensing.

[0028] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0029] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0030] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0031] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0032] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0033] The amide phthalocyanine dye is prepared by adding a methyl compound with high reactivity, 1,2,3,3-tetramethyl-3H-indole iodide (1) (including but not limited to the structures shown in formula (1)-(9)), 3-oxazol-4-yl-propenal (including but not limited to the structure shown in reaction formula (a)) into ethanol, then adding sodium acetate, and reacting at room temperature for 50 min, and then purifying the crude product by silica gel column chromatography to obtain the amide phthalocyanine dye.

[0034] The beneficial effects of the present application include that the synthesis method of the amide cyanine dye developed by the present application is simple, has less by-products, short reaction time, high yield, stable structure, high universality, and strong structure modifiability, can expand the absorption and emission wavelength of the cyanine dye from the short wave near-infrared region to the near-infrared two-band region by increasing the length of the conjugated chain, and can be used for biological imaging, cell mitochondrial super-resolution imaging, protein labeling, specific recognition of antibodies, nucleic acid labeling, DNA sequencing, and tumor photodynamic therapy. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 is the absorption spectrum and fluorescence spectrum of amide cyanine dyes 1a, 1b, 1c, 1d, Cy7-1 in methanol.

[0036] Fig. 2 is the fluorescence imaging application of amide cyanine dye 1a in neurons.

[0037] Fig. 3 is the super-resolution fluorescence imaging application of amide cyanine dye 1a for mitochondrial ridge in HeLa cells. DETAILED DESCRIPTION

[0038] The present application is further described in conjunction with the following specific examples and drawings. The process, conditions, experimental methods, etc. for implementing the present application are all general knowledge and common sense in the art, and the present application has no special limitation.

[0039] The following description of at least one example embodiment is merely exemplary in nature and is in no way intended to limit the present application or its application or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0040] In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the example embodiments can have different values.

[0041] Example 1. Synthesis of amide cyanine dye

[0042] 1,2,3,3-tetramethyl-3H-indole iodide (1 mmol), 0.5 mmol of 4- aldehyde oxazole or 2-methyloxazole-4-carboxaldehyde or 2-phenyloxazole-4- carboxaldehyde were added into 3 mL of ethanol, then 1 mmol of sodium acetate was added, and the reaction was carried out at room temperature for 5 min. The crude product was directly filtered to remove sodium acetate with diatomite, and the filtrate was evaporated under reduced pressure to remove the solvent, to obtain amide cyanine dye compounds 1a, 1b and 1c, with a yield of 99%, 98% and 97%, respectively.

[0043] 1,2,3,3-tetramethyl-3H-indole iodide (1 mmol), 0.5 mmol of 4- aldehyde oxazole were added into 3 mL of deuterated methanol, and the reaction was carried out at 75°C for 1 hour. The reaction solution was subjected to nuclear magnetic resonance internal standard method to obtain amide cyanine dye compound 1a with a yield of 83%.

[0044] 1,2,3,3-tetramethyl-3H-indole iodide (1 mmol), 0.5 mmol of 4- aldehyde oxazole were added into 3 mL of deuterated methanol, then 1 mmol of sodium acetate was added, and the reaction was carried out at 75°C for 1 min. The reaction solution was subjected to nuclear magnetic resonance internal standard method to obtain amide cyanine dye compound 1a with a yield of 99%.

[0045] amide cyanine dye compound 1a, 1 H NMR (600 MHz, DMSO-d6) δ 9.73 (s, 1H), 8.34 (d, J = 1.3 Hz, 1H), 8.20 (d, J = 14.1 Hz, 2H), 7.64 (d, J = 7.4 Hz, 2H), 7.41 (d, J = 3.9 Hz, 4H), 7.26 (dt, J = 8.2, 4.2 Hz, 2H), 6.07 (d, J = 14.1 Hz, 2H), 3.61 (s, 6H), 1.70 (s, 12H). 13 C NMR (151 MHz, DMSO-d6) δ 173.36, 159.77, 148.03, 142.68, 141.11, 128.36, 126.63, 124.92, 122.35, 111.24, 99.90, 48.96, 31.27, 26.87. HRMS (ESI): C 28 H 32 N3O + [M] + calcd 426.2540, found: 426.2537.

[0046] amide cyanine dye compound 1b, 1H NMR (600 MHz, DMSO-d6) δ 9.25 (s, 1H), 8.18 (d, J = 14.1 Hz, 2H), 7.64 (d, J = 7.4 Hz, 2H), 7.41 (d, J = 3.9 Hz, 4H), 7.26 (dq, J = 8.0, 4.3 Hz, 2H), 6.00 (d, J = 14.1 Hz, 2H), 3.60 (s, 6H), 2.18 (s, 3H), 1.70 (s, 12H). 13 C NMR (151 MHz, DMSO-d6) δ 173.18, 168.37, 148.86, 142.70, 141.05, 128.33, 124.84, 122.33, 119.61, 111.19, 99.66, 48.93, 31.17, 26.89, 22.92. HRMS (ESI): C 29 H 34 N3O + [M] + calcd 440.2696, found: 440.2688.

[0047] Amidocyanine dye compound 1c, 1 H NMR (500 MHz, DMSO-d6) δ 9.71 (s, 1H), 8.34 (d, J = 14.1 Hz, 2H), 8.09 (d, J = 7.3 Hz, 2H), 7.65 (d, J = 7.4 Hz, 2H), 7.62 (d, J = 7.2 Hz, 1H), 7.57 (t, J = 7.4 Hz, 2H), 7.40 (d, J = 6.5 Hz, 4H), 7.27 (t, J = 6.8 Hz, 2H), 6.00 (d, J = 14.1 Hz, 2H), 3.50 (s, 6H), 1.74 (s, 12H). 13 C NMR (126 MHz, DMSO-d6) δ 173.33, 165.45, 149.30, 142.63, 141.02, 134.33, 131.58, 128.50, 128.34, 128.15, 127.86, 127.72, 127.42, 124.94, 122.35, 111.24, 99.34, 49.03, 31.06, 26.89. HRMS (ESI): C 34 H 36 N3O + [M] + calcd 502.2853, found: 502.2846.

[0048] To a solution of 1-ethyl-2-methylbenzo[cd]indol-1-ium iodide (1 mmol) and 0.5 mmol of 2-phenyloxazole-4-carboxaldehyde or 2-methyloxazole-4-carboxaldehyde or 4-oxaldehyde oxazole in 3 mL of ethanol, 1 mmol of sodium acetate was added, and the reaction was allowed to proceed at room temperature for 5 min. The crude product was filtered through celite to remove sodium acetate without further purification. The filtrate was evaporated under reduced pressure to remove the solvent to obtain amide cyanine dye compounds 1d, 1e and 1f with a yield of 82%, 84% and 74%, respectively.

[0049] Amide cyanine dye compound 1d, 1 H NMR (500 MHz, DMSO-d6) δ 10.18 (s, 1H), 8.93 (d, J = 7.2 Hz, 2H), 8.69 (d, J = 13.9 Hz, 2H), 8.27 (dd, J = 15.2, 7.7 Hz, 4H), 7.83 (dd, J = 17.6, 8.0 Hz, 4H), 7.77 - 7.74 (m, 1H), 7.71 (t, J = 7.3 Hz, 2H), 7.62 (t, J = 7.7 Hz, 2H), 7.41 (d, J = 6.9 Hz, 2H), 6.48 (d, J = 13.7 Hz, 2H), 3.89 - 3.76 (m, 4H), 1.20 (t, J = 7.2 Hz, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 166.77, 153.19, 147.04, 139.79, 134.27, 133.03, 131.94, 129.75, 129.61, 129.36, 129.10, 128.84, 127.86, 124.18, 123.44, 110.56, 105.96, 38.40, 13.47. HRMS (ESI): C 38 H 32 N3O + [M] + calcd 546.2540, found: 546.2541.

[0050] Amide cyanine dye compound 1e, 1H NMR (500 MHz, DMSO-d6) δ 9.67 (s, 1H), 8.78 (s, 2H), 8.42 (d, J = 13.3 Hz, 2H), 8.28 (d, J = 7.2 Hz, 2H), 7.96 (t, J = 7.6 Hz, 2H), 7.78 (d, J = 7.8 Hz, 2H), 7.57 (t, J = 7.6 Hz, 2H), 7.30 (d, J = 6.4 Hz, 2H), 6.35 (d, J = 13.4 Hz, 2H), 3.82 - 3.72 (m, 4H), 2.43 (s, 3H), 1.20 (t, J = 7.1 Hz, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 169.85, 152.92, 146.49, 139.67, 133.11, 131.81, 129.81, 129.53, 129.31, 129.04, 128.77, 124.14, 123.31, 110.35, 106.04, 54.92, 48.60, 38.33, 23.17, 13.66. HRMS (ESI): C 33 H 30 N3O + [M] + calcd 484.2383, found: 484.2390.

[0051] Amidocyanine dye compound 1f, 1 H NMR (500 MHz, DMSO-d6) δ 9.14 (s, 1H), 8.76 (d, J = 12.4 Hz, 2H), 8.51 (d, J = 7.4 Hz, 2H), 8.27 (d, J = 7.7 Hz, 2H), 8.21 (d, J = 8.3 Hz, 2H), 8.08 - 8.04 (m, 2H), 7.98 (d, J = 6.7 Hz, 2H), 7.78 - 7.73 (m, 3H), 7.47 (d, J = 7.1 Hz, 2H), 4.62 - 4.45 (m, 4H), 1.46 (t, J = 7.0 Hz, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 162.72, 158.76, 139.29, 135.95, 135.60, 134.14, 131.98, 131.16, 130.34, 129.79, 129.68, 129.11, 128.03, 127.39, 126.74, 126.46, 126.32, 125.80, 123.76, 114.34, 106.78, 48.57, 40.63, 14.47, 11.81. HRMS (ESI): C 32 H28 N3O + [M] + calcd 470.2227, found: 470.2226.

[0052] To a solution of 1,1,2,3-tetramethyl-1H-benzo[e]indolium iodide (1 mmol) and 0.5 mmol of 4-oxaldehyde oxazole or 2-methyloxazole-4-carboxaldehyde or 2-phenyloxazole-4-carboxaldehyde in 3 mL of ethanol, 1 mmol of sodium acetate was added and the reaction mixture was stirred at room temperature for 5 min. The crude product was filtered through celite to remove sodium acetate and the filtrate was evaporated under reduced pressure to give amide cyanine dye compounds 3a, 3b and 3c in 99%, 91% and 94% yields, respectively.

[0053] Amide cyanine dye compound 3a, 1 H NMR (500 MHz, DMSO-d6) δ 9.39 (s, 1H), 8.41 (s, 1H), 8.33 (d, J = 14.2 Hz, 2H), 8.26 (d, J = 8.4 Hz, 2H), 8.09 (t, 4H), 7.77 (d, J = 8.9 Hz, 2H), 7.69 (t, J = 7.2 Hz, 2H), 7.52 (t, J = 7.2 Hz, 2H), 6.09 (d, J = 14.2 Hz, 2H), 3.74 (s, 6H), 1.98 (s, 12H). 13 C NMR (126 MHz, DMSO-d6) δ 174.41, 159.78, 147.04, 140.33, 133.26, 133.12, 131.40, 130.17, 129.92, 127.74, 127.45, 126.29, 124.83, 122.14, 111.70, 99.39, 50.80, 31.72, 26.50. HRMS (ESI): C 36 H 36 N3O + [M] + calcd 526.2853, found: 526.2856.

[0054] Amide cyanine dye compound 3b, 1H NMR (600 MHz, DMSO-d6) δ 9.14 (s, 1H), 8.31 (d, J = 14.0 Hz, 2H), 8.26 (d, J = 8.5 Hz, 2H), 8.10 (d, J = 8.9 Hz, 2H), 8.07 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 8.9 Hz, 2H), 7.69 (t, J = 7.2 Hz, 2H), 7.53 (t, J = 7.4 Hz, 2H), 6.04 (d, J = 14.2 Hz, 2H), 3.73 (s, 6H), 2.20 (s, 3H), 1.98 (s, 12H). 13 C NMR (151 MHz, DMSO-d6) δ 174.29, 168.37, 147.88, 140.39, 133.06, 131.40, 130.19, 129.94, 128.05, 127.75, 127.49, 124.82, 122.14, 111.72, 99.24, 50.77, 31.60, 26.53, 22.96. HRMS (ESI): C 37 H 38 N3O + [M] + calcd 540.3009, found: 540.3021.

[0055] Amidocyanine dye compound 3c, 1 H NMR (600 MHz, DMSO-d6) δ 9.71 (s, 1H), 8.46 (d, J = 14.0 Hz, 2H), 8.27 (d, J = 8.5 Hz, 2H), 8.13 - 8.06 (m, 6H), 7.75 (d, J = 8.7 Hz, 2H), 7.70 (t, J = 7.5 Hz, 2H), 7.65 (t, J = 7.4 Hz, 1H), 7.60 (t, J = 7.4 Hz, 2H), 7.53 (t, J = 7.5 Hz, 2H), 6.06 (d, J = 14.2 Hz, 2H), 3.64 (s, 6H), 2.01 (s, 12H). 13 C NMR (151 MHz, DMSO-d6) δ 174.40, 165.54, 148.26, 140.36, 134.47, 133.09, 131.63, 131.43, 130.21, 129.95, 128.57, 127.78, 127.72, 127.49, 124.87, 122.17, 111.72, 99.08, 50.85, 31.51, 26.54. HRMS (ESI): C 42 H 40 N3O + [M]+ calcd 602.3166, found: 602.3173.

[0056] To a solution of 2-(3-cyano-1,4,5,5-tetramethylfuran-2(5H)-ylidene)malononitrile (1 mmol) and 0.5 mmol of 4-oxaldehyde oxazole or 2-methyloxazole-4-carboxaldehyde or 2-phenyloxazole-4-carboxaldehyde in 3 mL of ethanol, 1 mmol of sodium acetate was added and the reaction mixture was stirred at room temperature for 5 min. The crude product was filtered through celite to remove sodium acetate and the filtrate was evaporated under reduced pressure to give amide cyanine dye compounds 4a, 4b and 4c in 90%, 90% and 86% yields, respectively.

[0057] Amide cyanine dye compound 4a, 1 H NMR (500 MHz, Methanol-d4) δ 8.33 (s, 1 H), 7.62 (d, J = 14.2 Hz, 2H), 5.97 (d, J = 14.2 Hz, 2H), 1.69 (s, 12H). 13 C NMR (126 MHz, Methanol-d4) δ 178.48, 171.19, 162.59, 145.09, 126.22, 115.95, 115.53, 114.91, 106.16, 105.53, 96.93, 27.07. HRMS (ESI): C 26 H 18 N7O3 - [M] - calcd 476.1477, found: 476.1490.

[0058] Amide cyanine dye compound 4b, 1 H NMR (500 MHz, Methanol-d4) δ 7.59 (d, J = 14.1 Hz, 2H), 5.96 (d, J = 14.2 Hz, 2H), 2.20 (s, 3H), 1.69 (s, 12H). 13 C NMR (126 MHz, Methanol-d4) δ 178.39, 172.52, 171.12, 145.75, 127.89, 115.98, 115.58, 114.87, 106.10, 96.88, 46.91, 27.09, 22.50. HRMS (ESI): C 27 H 20 N7O3 - [M] -calcd 490.1633, found: 490.1644.

[0059] Amidocyanine dye compound 4c, 1 H NMR (500 MHz, Methanol-d4) δ 7.98 (d, J = 7.2 Hz, 2H), 7.70 (d, J = 14.1 Hz, 2H), 7.61 (t, J = 7.4 Hz, 1H), 7.54 (t, J = 7.5 Hz, 2H), 6.05 (d, J = 14.1 Hz, 2H), 1.70 (s, 12H). 13 C NMR 13 C NMR (126 MHz, Methanol-d4) δ 178.38, 169.59, 146.05, 135.31, 133.17, 129.83, 128.66, 128.06, 115.97, 115.54, 106.22, 96.88, 27.13. HRMS (ESI): C 32 H 22 N7O3 + [M] + calcd 552.1790, found: 552.1799.

[0060] N-ethyl iodoquinol aldehyde (1 mmol), 0.5 mmol of 4-aldehyde oxazole or 2-methyl oxazole-4-carboxaldehyde or 2-phenyl oxazole-4-carboxaldehyde were added to 3 mL of ethanol, then 1 mmol of sodium acetate was added, and after 5 min of reaction under heating conditions at 75 °C, it was returned to room temperature, a large amount of solid was precipitated, which was directly filtered and washed with water, methanol, ethyl acetate, without the need for other purification methods, amidocyanine dye compounds 5a, 5b and 5c were obtained with a yield of 97%, 98% and 96%, respectively.

[0061] Amidocyanine dye compound 5a, 1 H NMR (600 MHz, DMSO-d6) δ 9.54 (s, 1H), 8.37 (s, 1H), 8.08 (d, J = 9.3 Hz, 2H), 7.95 (d, J = 13.7 Hz, 2H), 7.90 (d, J = 6.3 Hz, 2H), 7.86 (d, J = 7.9 Hz, 2H), 7.77 (t, J = 7.8 Hz, 2H), 7.48 (t, J = 7.5 Hz, 2H), 6.05 (d, J = 13.6 Hz, 2H), 4.46 (s, 4H), 1.41 (t, J = 7.2 Hz, 6H). 13C NMR (151 MHz, DMSO-d6) δ 159.48, 151.00, 144.42, 138.75, 136.46, 132.79, 129.26, 125.16, 124.84, 124.60, 119.43, 116.21, 102.26, 43.23, 12.10. HRMS (ESI): C 28 H 28 N3O + [M] + calcd 422.2227, found: 422.2237.

[0062] Amidocyanine dye compound 5b, 1 H NMR (600 MHz, DMSO-d6) δ 9.33 (s, 1H), 8.00 (d, J = 9.3 Hz, 2H), 7.93 (d, J = 13.4 Hz, 2H), 7.86 (d, J = 9.5 Hz, 2H), 7.83 (d, J = 8.7 Hz, 2H), 7.79 (d, J = 7.6 Hz, 2H), 7.71 (t, J = 7.3 Hz, 2H), 7.41 (t, J = 7.4 Hz, 2H), 5.99 (d, J = 13.3 Hz, 2H), 4.41 (s, 4H), 2.18 (s, 3H), 1.38 (t, J = 7.1 Hz, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 168.22, 150.76, 145.07, 138.67, 136.13, 132.61, 129.13, 126.46, 124.97, 124.70, 119.50, 116.03, 102.28, 43.26, 22.82, 11.93. HRMS (ESI): C 29 H 30 N3O + [M] + calcd 436.2383, found: 436.2388.

[0063] Amidocyanine dye compound 5c, 1H NMR (500 MHz, DMSO-d6) δ 9.81 (s, 1H), 8.11 - 8.04 (m, 6H), 7.93 (d, J = 9.5 Hz, 2H), 7.84 (d, J = 7.5 Hz, 4H), 7.74 (t, J = 7.7 Hz, 2H), 7.63 (d, J = 7.1 Hz, 1H), 7.59 (t, J = 7.3 Hz, 2H), 7.45 (t, J = 7.4 Hz, 2H), 6.07 (d, J = 13.5 Hz, 2H), 4.38 (s, 4H), 1.32 (t, J = 7.0 Hz, 6H). 13 C NMR (126 MHz, DMSO-d6) δ 165.71, 150.90, 145.39, 138.69, 136.38, 134.86, 132.70, 131.51, 129.20, 128.56, 127.55, 126.11, 125.09, 124.76, 119.48, 116.08, 102.30, 43.34, 11.85. HRMS (ESI): C 29 H 30 N3O + [M] + calcd 436.2383, found: 436.2388.

[0064] To 1-methyl-2-methylbenzo[l,2-d]thiazolium iodide (1 mmol), 0.5 mmol of 4- aldehyde oxazole or 2-methyloxazole-4-carboxaldehyde or 2-phenyloxazole-4- carboxaldehyde was added to 3 mL of ethanol, then 1 mmol of sodium acetate was added, and the reaction was carried out under heating conditions at 75 °C for 5 min, and then it was restored to room temperature, a large amount of solid was precipitated, the solid was directly filtered and washed with water, methanol, ethyl acetate, without other purification method, to obtain amide cyanine dye compounds 6a, 6b and 6c, with a yield of 90%, 90% and 86% respectively.

[0065] Amide cyanine dye compound 6a, 1 H NMR (500 MHz, DMSO-d6) δ 9.32 (s, 1H), 8.31 (d, J = 1.3 Hz, 1H), 8.02 (d, J = 7.9 Hz, 2H), 7.71 - 7.65 (m, 4H), 7.56 (t, J = 7.8 Hz, 2H), 7.41 (t, J = 7.6 Hz, 2H), 6.17 (d, J = 13.5 Hz, 2H), 3.78 (s, 6H). 13C NMR (126 MHz, DMSO-d6) δ 164.33, 159.71, 145.17, 141.97, 139.69, 127.98, 125.20, 125.12, 123.00, 113.55, 97.66, 33.56. HRMS (ESI): C 22 H 20 N3OS2 + [M] + calcd 406.1042, found: 406.1053.

[0066] Amidocyanine dye compound 6b, 1 H NMR (500 MHz, DMSO-d6) δ 9.07 (s, 1H), 8.00 (d, J = 7.8 Hz, 2H), 7.67 - 7.61 (m, 4H), 7.53 (t, J = 7.8 Hz, 2H), 7.39 (t, J = 7.6 Hz, 2H), 6.12 (d, J = 13.4 Hz, 2H), 3.75 (s, 6H), 2.18 (s, 3H). 13 C NMR (126 MHz, DMSO-d6) δ 152.05, 148.20, 132.42, 128.85, 116.67, 114.22, 114.13, 112.31, 104.00, 90.14, 34.22, 25.20. HRMS (ESI): C 23 H 22 N3OS2 + [M] + calcd 420.1199, found: 420.1208.

[0067] Amidocyanine dye compound 6c, 1 H NMR (500 MHz, DMSO-d6) δ 9.65 (s, 1H), 8.09 (d, J = 7.3 Hz, 2H), 8.03 (d, J = 7.9 Hz, 2H), 7.83 (d, J = 13.4 Hz, 2H), 7.68 (d, J = 8.3 Hz, 2H), 7.63 (t, J = 7.3 Hz, 1H), 7.56 (q, J = 8.1 Hz, 4H), 7.41 (t, J = 7.7 Hz, 2H), 6.13 (d, J = 13.4 Hz, 2H), 3.72 (s, 6H). 13C NMR (126 MHz, DMSO-d6) δ 165.43, 164.28, 146.44, 141.88, 134.43, 131.56, 128.42, 127.93, 125.12, 124.82, 122.94, 113.47, 97.30, 33.44. HRMS (ESI): C 28 H 24 N3OS2 + [M] + calcd 482.1355, found: 482.1369.

[0068] To 1 -methyl-2-methylnaphtho[1,2-d]thiazolium iodide (1 mmol), 0.5 mmol of 4- aldehyde oxazole or 2-methyloxazole-4-carboxaldehyde or 2-phenyloxazole-4- carboxaldehyde was added to 3 mL of ethanol, then 1 mmol of sodium acetate was added, and a large amount of solid was precipitated after 5 min of reaction under heating conditions at 75 °C. The solid was directly filtered and washed with water, methanol, ethyl acetate, and the amide cyanine dye compounds 7a, 7b and 7c were obtained without the need for other purification methods, with yields of 99%, 98% and 97%, respectively.

[0069] Amide cyanine dye compound 7a, 1 H NMR (500 MHz, DMSO-d6) δ 9.35 (s, 1 H), 8.53 (d, J = 8.6 Hz, 2H), 8.40 (s, 1 H), 8.05 - 7.99 (m, 4H), 7.91 (d, J = 8.6 Hz, 2H), 7.66 - 7.55 (m, 6H), 6.24 (d, J = 13.5 Hz, 2H), 4.21 (s, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 170.38, 164.53, 159.87, 143.82, 137.12, 133.32, 132.49, 129.51, 127.26, 126.57, 123.30, 122.11, 121.69, 119.54, 98.00, 54.43. HRMS (ESI): C 30 H 24 N3OS2 + [M] + calcd 506.1355, found: 506.1361.

[0070] Amide cyanine dye compound 7b, 1H NMR (500 MHz, DMSO-d6) δ 9.12 (s, 1H), 8.70 (d, J = 8.7 Hz, 2H), 8.14 (d, J = 8.0 Hz, 2H), 8.09 (d, J = 8.7 Hz, 2H), 8.00 (d, J = 8.8 Hz, 2H), 7.75 - 7.68 (m, 6H), 6.24 (d, J = 13.4 Hz, 2H), 4.30 (s, 6H), 2.20 (s, 3H). 13 C NMR (151 MHz, DMSO-d6) δ 164.64, 137.38, 133.44, 131.64, 129.62, 127.37, 126.69, 126.53, 125.04, 123.35, 122.33, 121.90, 119.65, 97.88, 54.40, 21.06. HRMS (ESI): C 31 H 26 N3OS2 + [M] + calcd 520.1512, found: 520.1520.

[0071] amide merocyanine dye compound 7c, 1 H NMR (500 MHz, DMSO-d6) δ 9.69 (s, 1H), 8.64 - 8.57 (m, 2H), 8.14 - 8.07 (m, 6H), 8.00 - 7.96 (m, 2H), 7.84 (dd, J = 13.1, 7.3 Hz, 2H), 7.71 - 7.64 (m, 5H), 7.60 (t, J = 6.8 Hz, 2H), 6.24 (d, J = 13.3 Hz, 2H), 4.21 (d, J = 12.5 Hz, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 165.45, 164.79, 145.05, 137.30, 134.51, 133.40, 131.66, 129.60, 128.52, 127.98, 127.37, 126.67, 126.61, 124.72, 123.37, 122.18, 121.82, 119.61, 97.75. HRMS (ESI): C 36 H 28 N3OS2 + [M] + calcd 582.1668, found: 582.1662.

[0072] Four fluoroboric acid-4-methyl-2-phenyl-1-benzopyrylium (1 mmol), 0.5 mmol of 2-phenyloxazole-4-carboxaldehyde or 2-methyloxazole-4-carboxaldehyde or 4- aldehyde oxazole was added to 3 mL of ethanol, then 1 mmol of sodium acetate was added, and a large amount of solid was precipitated after 5 min of reaction under heating conditions at 75 °C, the solid was directly filtered and washed with water, methanol, ethyl acetate, without the need for other purification methods, to obtain amide cyanine dye compounds 8a, 8b and 8c with a yield of 86%, 84% and 74%, respectively.

[0073] Amide cyanine dye compound 8a, 1 H NMR (600 MHz, DMSO-d6) δ 8.41 (s, 2H), 8.09 (d, J = 7.7 Hz, 2H), 8.00 - 7.95 (m, 4H), 7.88 - 7.86 (m, 6H), 7.41 (t, J = 7.3 Hz, 3H), 7.37 (d, J = 7.1 Hz, 2H), 7.23 (t, J = 7.2 Hz, 2H), 7.19 (s, 2H), 7.13 (t, J = 7.4 Hz, 2H), 7.04 - 7.00 (m, 3H). 13 C NMR (151 MHz, DMSO-d6) δ 150.84, 148.24, 132.69, 132.51, 129.17, 128.99, 128.96, 128.42, 124.54, 124.36, 124.27, 123.18, 122.58, 117.13, 111.12, 101.08, 39.52. HRMS (ESI): C 42 H 30 NO3 + [M] + calcd 596.2220, found: 596.2210.

[0074] Amide cyanine dye compound 8b, 1 H NMR (600 MHz, DMSO-d6) δ 8.00 (d, J = 7.4 Hz, 2H), 7.81 (d, J = 7.5 Hz, 4H), 7.28 (t, J = 7.6 Hz, 4H), 7.23 - 7.18 (m, 4H), 7.14 - 7.10 (m, 5H), 7.01 - 6.98 (m, 4H), 6.95 (s, 2H), 2.18 (s, 3H). 13C NMR (151 MHz, DMSO-d6) δ 150.98, 148.39, 132.73, 129.13, 128.68, 128.59, 128.53, 124.74, 124.60, 124.54, 124.29, 124.26, 123.99, 123.38, 122.73, 117.28, 111.24, 101.31, 53.94, 23.17. HRMS (ESI): C 37 H 28 NO3 + [M] + calcd 534.2064, found: 534.2053.

[0075] Amidocyanine dye compound 8c, 1 H NMR (500 MHz, DMSO-d6) δ 8.52 (s, 2H), 8.22 (d, J = 7.7 Hz, 2H), 8.03 (d, J = 7.6 Hz, 4H), 7.51 (t, J = 7.5 Hz, 4H), 7.47 - 7.41 (m, 3H), 7.38 - 7.28 (m, 5H), 7.22 (t, J = 7.4 Hz, 4H), 7.17 (s, 2H). 13 C NMR (151 MHz, DMSO-d6) δ 155.73, 134.37, 131.87, 131.17, 129.26, 129.16, 128.92, 128.68, 128.60, 128.57, 126.40, 125.58, 124.81, 124.74, 124.53, 124.30, 123.36, 118.59, 106.98. HRMS (ESI): C 36 H 26 NO3 + [M] + calcd 520.1907, found: 520.1898.

[0076] Amidocyanine dye compound 8c,

[0077] Amidocyanine dye compound 9a,1 H NMR (500 MHz, DMSO-d6) δ 9.64 (s, 1H), 8.13 (d, J = 7.2 Hz, 2H), 7.92 (d, J = 8.7 Hz, 2H), 7.74 (d, J = 13.2 Hz, 2H), 7.65 (t, J = 7.3 Hz, 1H), 7.59 (t, J = 7.4 Hz, 2H), 6.99 - 6.93 (m, 4H), 6.25 (d, J = 13.2 Hz, 2H), 3.82 (s, 6H), 3.58 (s, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 170.11, 166.33, 160.18, 148.24, 144.83, 135.03, 132.09, 128.98, 128.48, 127.08, 126.20, 115.98, 113.01, 101.85, 100.22, 56.18, 34.75, 19.03. HRMS (ESI): C 30 H 28 N3O3Se2 + [M] + calcd 638.0456, found: 638.0478.

[0078] Amidocyanine dye compound 9b, 1 H NMR (600 MHz, DMSO-d6) δ 9.06 (s, 1H), 7.93 (d, J = 8.7 Hz, 2H), 7.58 (d, J = 13.1 Hz, 2H), 7.12 (s, 2H), 6.97 (d, J = 8.7 Hz, 2H), 6.25 (d, J = 13.2 Hz, 2H), 3.85 (s, 6H), 3.71 (s, 6H), 2.17 (s, 3H). 13 C NMR (151 MHz, DMSO-d6) δ 169.74, 168.35, 159.82, 147.33, 144.67, 126.68, 126.13, 115.71, 112.52, 101.52, 100.20, 55.85, 34.55, 23.09. HRMS (ESI): C 25 H 26 N3O3Se2 + [M] + calcd 576.0299, found: 576.0314.

[0079] Amidocyanine dye compound 9c, 1H NMR (500 MHz, DMSO-d6) δ 9.37 (s, 1H), 8.33 (s, 1H), 7.93 (d, J = 8.6 Hz, 2H), 7.59 (d, J = 13.2 Hz, 2H), 7.05 (s, 2H), 6.96 (d, J = 8.6 Hz, 2H), 6.29 (d, J = 13.3 Hz, 2H), 3.84 (s, 6H), 3.68 (s, 6H). 13 C NMR (151 MHz, DMSO-d6) δ 169.89, 168.60, 159.80, 146.46, 144.57, 126.70, 124.40, 115.74, 112.57, 101.74, 100.12, 55.81, 34.58. HRMS (ESI): C 25 H 26 N3O3Se2 + [M] + calcd 562.0143, found: 562.00131.

[0080] Example 2. Synthesis of amide pyropheophytin dyes with increasing conjugated chain length of the methine chain

[0081] Compound 2a (10 mmol) and (formylmethylene)triphenylphosphonium (10 mmol) were dissolved in 20 mL of toluene and stirred at 80 °C for 18 h, then concentrated under reduced pressure. The crude product was purified by flash column chromatography to isolate compound 2b, and compounds 2c and 2d were synthesized in the same way as described above.

[0082] Compound 2b, 1 H NMR (500 MHz, Chloroform-d) δ 9.69 (d, J = 7.8 Hz, 1H), 7.94 (s, 2H), 7.35 (d, J = 15.6 Hz, 1H), 6.89 (dd, J = 15.6, 7.8 Hz, 1H). 13 C NMR (126 MHz, Chloroform-d) δ 193.12, 152.07, 140.06, 139.15, 136.94, 130.53.

[0083] Compound 2c, 1 H NMR (500 MHz, Chloroform-d) δ 9.62 (d, J = 7.9 Hz, 1H), 7.89 (s, 1H), 7.77 (s, 1H), 7.21 (dq, J = 14.9, 5.2, 3.7 Hz, 2H), 6.86 (d, J = 13.9 Hz, 1H), 6.29 (dd, J = 13.7, 8.0 Hz, 1H).13 C NMR (126 MHz, Chloroform-d) δ 193.57, 151.72, 150.91, 138.02, 132.57, 129.00, 128.47. HRMS (ESI): C8H7NNaO2 + [M+Na] + calcd 172.0369, found: 172.0365.

[0084] Compound 2d, 1 H NMR (500 MHz, Chloroform-d) δ 9.59 (d, J = 7.9 Hz, 1H), 7.87 (s, 1H), 7.69 (s, 1H), 7.14 (ddd, J = 30.8, 15.2, 11.2 Hz, 2H), 6.79 (dd, J = 14.7, 11.3 Hz, 1H), 6.66 - 6.55 (m, 2H), 6.20 (dd, J = 15.2, 7.9 Hz, 1H). 13 C NMR (126 MHz, Chloroform-d) δ 193.58, 151.61, 151.50, 141.81, 138.39, 136.88, 131.78, 131.25, 130.07, 125.06, 77.16.

[0085] Compound 2d, was added into 3 mL of ethanol, then 1 mmol of sodium acetate was added, and the reaction was carried out at room temperature for 50 min. The crude product was purified by silica gel column chromatography to obtain the amide cyanine dye compound Cy7-1, with a yield of 68%.

[0086] Amide cyanine dye compound Cy7-1, 1 H NMR (500 MHz, Methanol-d4) δ 8.47 (s, 1H), 8.17 (d, J = 14.2 Hz, 2H), 7.52 (d, J = 7.3 Hz, 2H), 7.42 (d, J = 7.6 Hz, 2H), 7.34 (d, J = 7.9 Hz, 2H), 7.30 (d, J = 7.3 Hz, 2H), 6.10 (d, J = 14.2 Hz, 2H), 3.66 (s, 6H), 1.75 (s, 12H). 13C NMR (151 MHz, DMSO-d6) δ 173.41, 159.78, 159.70, 148.13, 142.93, 142.70, 142.66, 141.08, 140.66, 128.36, 125.19, 124.96, 122.35, 111.48, 111.26, 110.66, 99.64, 49.00, 48.41, 31.45, 31.25, 31.00, 27.05, 26.88, 26.85. HRMS (ESI): C 30 H 34 N3O + [M] + calcd 452.2696, found: 452.2701.

[0087] Amidocyanine dye compound Cy9-1 was synthesized according to the procedure of reference compound Cy7-1, 1 H NMR (600 MHz, Chloroform-d) δ 8.69 (s, 1H), 8.15 (s, 1H), 7.89 (s, 1H), 7.84 (s, 1H), 7.81 (d, J = 8.4 Hz, 1H), 7.58 - 7.54 (m, 2H), 7.52 (d, 1H), 7.39 (t, J = 7.7 Hz, 2H), 7.35 (d, J = 7.4 Hz, 2H), 7.24 (d, J = 7.7 Hz, 1H), 7.11 (d, J = 8.0 Hz, 2H), 6.99 (d, 1H), 6.46 (d, J = 13.9 Hz, 2H), 4.29 (s, 3H), 3.70 (s, 3H), 1.78 (s, 6H), 1.70 (s, 6H). 13 C NMR (151 MHz, Chloroform-d) δ 173.91, 151.79, 142.83, 138.68, 132.57, 130.22, 130.07, 128.94, 128.43, 125.53, 122.17, 114.56, 110.81, 102.17, 49.23, 36.05, 29.84, 29.46, 28.25, 27.35, 26.86, 25.67. HRMS (ESI): C 30 H 34 N3O + [M] + calcd 452.2696, found: 452.2701.

[0088] Amidocyanine dye compound Cy1050 was synthesized according to the procedure of reference compound Cy7-1,1 H NMR (500 MHz, Methanol-d4) δ 8.97 (d, J = 7.4 Hz, 1H), 8.76 - 8.69 (m, 2H), 8.46 (d, J = 8.1 Hz, 1H), 8.22 (d, J = 8.0 Hz, 1H), 8.10 - 8.02 (m, 3H), 7.98 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 7.4 Hz, 1H), 7.86 - 7.81 (m, 2H), 7.73 - 7.67 (m, 2H), 7.65 (d, J = 7.3 Hz, 1H), 7.60 - 7.56 (m, 2H), 7.48 (d, J = 15.3 Hz, 2H), 6.59 (d, J = 4.0 Hz, 1H), 4.63 (q, J = 7.3 Hz, 2H), 4.52 (q, J = 6.9 Hz, 2H), 1.62 - 1.54 (m, 6H). 13 C NMR (151 MHz, Methanol-d4) δ 157.44, 142.21, 136.14, 135.99, 134.85, 134.54, 134.14, 133.19, 132.61, 131.75, 131.66, 130.83, 130.29, 129.96, 129.73, 125.99, 116.16, 113.30, 57.47, 57.33, 41.62, 41.37, 15.09, 14.26. HRMS (ESI): C 34 H 30 N3O + [M] + calcd 496.2383, found: 496.2380.

[0089] Example 3. The amide corrole dyes prepared in the embodiments of the present application have tunable absorption / emission spectra and strong structural modifiability. By increasing the length of the conjugated chain, the absorption and emission wavelengths of the corrole dyes can be reached from the short-wave near-infrared region to the near-infrared two-region band. The absorption spectrum and fluorescence emission spectrum of the amide corrole dyes prepared in embodiments 1 and 2 of the present application cover the short-wave near-infrared band to the near-infrared two-region band (Figure 1). The absorption spectrum of the amide corrole dyes covers a range from 550 nm to 900 nm, and the fluorescence emission peak covers a range from 650 nm to 1200 nm.

[0090] Example 4. Confocal fluorescence imaging of the amide corrole dye prepared in the embodiment of the present application in neuron cells and super-resolution fluorescence imaging of mitochondria in HeLa cells. After culturing, the neuron cells were incubated with the amide corrole dye 1a for 15 min, then the cell culture solution was removed and PBS buffer was added. Then the cell morphology was found with a confocal microscope, and fluorescence imaging was performed with a fluorescence excitation wavelength of 637 nm, as shown in Figure 2, the corrole dye has high light stability in the cells, which can be used for long-term imaging research of the cells, and the near-infrared fluorescence has the advantage of strong penetration, avoiding the interference of the biological own fluorescence background, and more accurately reflecting the cell imaging effect. In addition, as shown in Figure 3, the amide corrole dye 1a can be used for stimulated emission depletion (STED) imaging of cell mitochondria, and higher resolution fluorescence imaging can be achieved in a STED microscope using a 775 nm extinction laser.

[0091] The protection scope of the present application is not limited to the above embodiments. Changes and advantages that can be thought of by those skilled in the art without departing from the spirit and scope of the present application are included in the present application, and are protected by the appended claims.

Claims

1. An amido-cyanine dye, characterized in that, The chemical structure is shown below as Formula I: In formula I, n is selected from 0, 1, 2 or 3; R1 is selected from one of hydrogen, alkyl, phenyl; R2 is selected from a heteroatom-containing polycyclic ring, wherein the heteroatom is selected from N, O, S, Se, and the heteroatom-containing polycyclic ring is connected to a methyl group.

2. The amido-cyanine dye according to claim 1, characterized in that n is selected from 0, 1, 2 or 3; R1 is selected from one of hydrogen, methyl, phenyl; R2is selected from the following structures:

3. A method for synthesizing an amido-cyanine dye, characterized by, The synthesis method comprises the following steps: The methylation compound, aldehyde oxazole compound having higher reactivity are added into the organic solvent, then the reaction is carried out with or without adding the base, to obtain the amide corrole dye of general formula I structure, the reaction process of the synthesis method is shown in the following reaction formula (a): In reaction formula (a), n, R1, and R2 are defined as in claim 1.

4. The method of synthesis of claim 3, wherein, The temperature of the reaction is -10℃ to 80℃. And / or, the time of the reaction is 1min to 120min.

5. The method of synthesis of claim 3, wherein, The base in the reaction is selected from an organic base or an inorganic base, wherein the inorganic base is selected from any one of sodium hydroxide, potassium hydroxide, potassium carbonate, cesium carbonate, sodium acetate, and sodium ethoxide; and the organic base is selected from one of triethylamine, piperidine, and diisopropylethylamine.

6. The method of synthesis of claim 3, wherein, The molar ratio of the methyl compound, the aldehyde oxazole compound, and the base with higher reactivity is 2-5:1:0-2.

7. The method of synthesis of claim 3, wherein, The organic solvent is selected from one or a combination of methanol, ethanol, propanol, acetonitrile, or N,N-dimethylformamide (DMF).

8. The amide cyanine dye obtained by the synthesis method according to any one of claims 3-7.

9. Use of the amide cyanine dye according to claim 1 or 8 in vitro and / or cellular imaging and biosensing.

10. Use according to claim 9, wherein the compound is ###0002### The use includes the use of the amide cyanine dye in cellular mitochondrial super-resolution fluorescence imaging, protein labeling, specific recognition of antibodies, nucleic acid labeling, fluorescent probes, DNA sequencing, and tumor photodynamic therapy.

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