1. A compound having the structure:

wherein: r₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀Is independently selected from the group consisting of a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a sulfonic acid group, an ester group and a hydroxyl group; and wherein R is₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀May be the same or different.

2. A compound according to claim 1, wherein R is₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀Are all hydrogen atoms.

3. A process for the preparation of a compound according to claim 1 or 2, comprising the steps of: reacting a compound shown in a formula (III) with a compound shown in a formula (IV) to obtain a compound shown in a formula (V), and reacting the compound shown in the formula (V) with a compound shown in a formula (VI) to obtain a compound shown in a formula (II), wherein the reaction formulas are respectively as follows:

step 1:

step 2:

wherein: r₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀Is independently selected from the group consisting of a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a sulfonic acid group, an ester group and a hydroxyl group; and wherein R is₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀May be the same or different.

4. The method of claim 3, comprising the steps of:

step (1): heating and refluxing a compound of a formula (III), a compound of a formula (IV) and cesium carbonate in acetonitrile for reaction, after the reaction is finished, performing suction filtration under reduced pressure to obtain a solid, washing the solid with dichloromethane to obtain a filtrate, and performing rotary evaporation under reduced pressure to obtain a crude product of a compound of a formula (V). The crude product is further separated by a chromatographic column, and the mixture system of dichloromethane and methanol is an eluent, so that the pure compound of the formula (V) can be obtained.

Step (2): reacting a compound of a formula (V), a compound of a formula (VI), 4-Dimethylaminopyridine (DMAP) and Dicyclohexylcarbodiimide (DCC) in an anhydrous N, N-Dimethylformamide (DMF) and anhydrous dichloromethane system (V/V: 1:1) at normal temperature for a period of time, after the reaction is finished, carrying out reduced pressure rotary evaporation to remove dichloromethane, then adding water to precipitate and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (I). The crude product is further separated by a chromatographic column, and the mixture system of dichloromethane and methanol is an eluent, so that the pure compound of the formula (I) can be obtained.

5. A fluorescent probe composition for measuring, detecting or screening hypochlorous acid, comprising the compound of any one of claims 1-2.

6. The fluorescent probe composition of claim 5, said compound being:

7. the fluorescent probe composition of claim 5 or 6, wherein the fluorescent probe composition further comprises a solvent, an acid, a base, a buffer solution, or a combination thereof.

8. A method for detecting the presence of or determining the content of hypochlorous acid in a sample, comprising:

a) contacting a compound of any one of claims 1-2 with a sample to form a fluorescent compound;

b) determining the fluorescent properties of the fluorescent compound.

9. The method of claim 8, wherein the sample is a chemical sample or a biological sample.

10. A compound according to any one of claims 1-2 for use in fluorescence imaging of cells.

Background

Cancer, one of the major diseases threatening human health, has a high mortality rate. Early diagnosis of cancer is difficult and is one of the major causes of high mortality of cancer. The difficulty in early diagnosis is that cancer cells are not easily distinguished from normal cells. Therefore, establishing a new method for distinguishing cancer cells from normal cells is of great significance for early diagnosis of cancer and improvement of therapeutic effect.

Due to the large variability between cancer and normal cells, the concentration of reactive oxygen species in cancer cells is about 10 times that in normal cells. Hypochlorous acid (HOCl), a kind of active oxygen, has attracted much attention because of its extremely high reactivity and is very active in cancer cells, and is produced by chlorine ions and hydrogen peroxide under the catalytic action of Myeloperoxidase (MPO). The over-expression of hypochlorous acid in cancer cells provides the possibility to distinguish cancer cells from normal cells. In addition, protein receptors on the cell membrane surface of cancer cells are also subject to a corresponding change due to cellular heterogeneity, such as sodium-dependent vitamin complex transporter (SMVT), which is overexpressed on the cell membrane surface of cancer cells. This also provides support for distinguishing cancer cells from normal cells.

Due to the advantages of high sensitivity, high selectivity, remarkable space-time resolution, real-time monitoring and the like, the small-molecule fluorescent probe is widely applied to the determination of analytes in biological samples as a non-invasive tool. In recent years, the development of small molecule fluorescent probes for distinguishing cancer cells from normal cells is very rapid, but the reported ways of entering the fluorescent probes into cells are single (such as free diffusion), and most of the fluorescent probes only detect one marker (such as thiols or reactive oxygen species), so that the probes cannot be selectively enriched in the cancer cells and are easy to cause false positive results. In addition, the probe has some limitations, such as complex synthesis and long response time of markers, which is not favorable for popularization and application. Therefore, a simple hypochlorous acid response-based fluorescent probe is explored, the fluorescent probe can be selectively enriched in cancer cells, and a novel method for distinguishing cancer cells from normal cells in a fluorescence visualization mode is of great significance.

Disclosure of Invention

In view of the above, the present invention aims to provide a hypochlorous acid fluorescent probe having a function of distinguishing cancer cells from normal cells, and a preparation method and use thereof, wherein the hypochlorous acid fluorescent probe has characteristics of simple synthesis, good specificity, high sensitivity, transient response, and selective enrichment in cancer cells, and can effectively measure, detect or screen hypochlorous acid under physiological level conditions, and simultaneously has a function of distinguishing normal cells from cancer cells.

Specifically, the invention provides a compound having a structure represented by formula (I):

in the formula (I), R₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀Is independently selected from the group consisting of a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a sulfonic acid group, an ester group and a hydroxyl group; and wherein R is₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀May be the same or different.

In some embodiments of the invention, the compound of the invention is R₁，R₂，R₃，R₄，R₅， R₆，R₇，R₈，R₉And R₁₀A compound of formula (ii) which are both hydrogen atoms, having the formula:

the invention also provides a process for the preparation of a compound of formula (i) comprising the steps of:

step (1): reacting a compound of formula (III) with a compound of formula (IV) to produce a compound of formula (V), wherein the reaction formula is as follows:

step (2): reacting a compound of formula (V) with a compound of formula (VI) to produce a compound of formula (II):

in the formulae (I) and (III) to (IV): r₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀Independently selected from the group consisting of hydrogen atoms, straight or branched chain alkyl groups, straight or branched chain alkoxy groups, sulfonic acid groups, ester groups and hydroxyl groups; and wherein R is₁，R₂，R₃，R₄，R₅，R₆，R₇，R₈，R₉And R₁₀May be the same or different.

Specifically, the method comprises the following steps: heating and refluxing the compound of the formula (III), the compound of the formula (IV) and cesium carbonate in acetonitrile for reaction, after the reaction is finished, obtaining a solid through reduced pressure suction filtration, washing the solid with dichloromethane to obtain a filtrate, and performing reduced pressure rotary evaporation to obtain a crude product of the compound of the formula (V). The crude product is further separated by a chromatographic column, and the mixture system of dichloromethane and methanol is an eluent, so that the pure compound of the formula (V) can be obtained. Reacting a compound of a formula (V), a compound of a formula (VI), 4-Dimethylaminopyridine (DMAP) and Dicyclohexylcarbodiimide (DCC) in an anhydrous N, N-Dimethylformamide (DMF) and anhydrous dichloromethane system (V/V: 1:1) at normal temperature for a period of time, after the reaction is finished, decompressing and distilling to remove dichloromethane, adding water to precipitate out and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (I). The crude product is further separated by a chromatographic column, and the mixture of dichloromethane and methanol is used as an eluent, so that the pure compound of the formula (I) can be obtained.

In some embodiments of the invention, the molar ratio of the compound of formula (iii) to the compound of formula (iv) is from 1:1 to 1:10, and the molar ratio of the compound of formula (v) to the compound of formula (vi) is from 1:1 to 1: 10.

In some embodiments of the invention, the reaction time in step (1) of the process for the preparation of compounds of formula (I) is 3 to 10 hours; the reaction time in the step (2) is 10-20 hours.

The invention also provides a fluorescent probe composition for measuring, detecting or screening hypochlorous acid, which comprises the compound of formula (I) of the invention.

In some embodiments of the invention, the compound of formula (I) has the following structure:

in some embodiments of the invention, the fluorescent probe composition further comprises a solvent, an acid, a base, a buffer solution, or a combination thereof.

The present invention also provides a method for detecting the presence of or measuring the content of hypochlorous acid in a sample, comprising:

a) contacting the compound of formula (I) or formula (ii) with a sample to form a fluorescent compound;

b) determining the fluorescent properties of the fluorescent compound.

In some embodiments of the invention, the sample is a chemical sample or a biological sample.

In some embodiments of the invention, the sample is a biological sample comprising water, blood, microorganisms, or animal cells or tissues.

The invention also provides a kit for detecting the presence of hypochlorous acid in a sample or determining the amount of hypochlorous acid in a sample, comprising the compound of formula (I) or (ii).

The invention also provides application of the compound shown in the formula (I) or the formula (II) in cell fluorescence imaging.

Compared with the prior art, the invention has the following remarkable advantages and effects:

(1) has the function of distinguishing cancer cells from normal cells

The hypochlorous acid fluorescent probe can be selectively enriched in cancer cells, and provides a new way for visually distinguishing the cancer cells from normal cells by fluorescence.

(2) Transient response

The hypochlorous acid fluorescent probe can respond to hypochlorous acid instantly and is beneficial to implementation and detection of the hypochlorous acid.

(3) Good specificity

The hypochlorous acid fluorescent probe can selectively and specifically react with hypochlorous acid to generate a fluorescence change product, and compared with other common metal ions and other substances in a living body, the hypochlorous acid fluorescent probe comprises but not limited to blank, potassium ions, calcium ions, sodium ions, magnesium ions, zinc ions, ferric ions, ferrous ions, copper ions, fluorine ions, iodide ions, chloride ions, bromide ions, nitrate radicals, nitrite radicals, carbonate radicals, sulfate radicals, cysteine (Cys), homocysteine (Hcy), Glutathione (GSH), sulfur ions, hydrogen peroxide, tert-butyl peroxide free radicals, hydroxyl free radicals, superoxide anions, singlet oxygen, nitric oxide and the like.

(4) Has low biological toxicity and can be applied under physiological level conditions

The fluorescent probe has the characteristic of low toxicity, and is favorable for applying the fluorescent probe to the detection or imaging of hypochlorous acid in a cell sample for a long time.

(5) High sensitivity

The hypochlorous acid fluorescent probe disclosed by the invention is very sensitive to reaction with hypochlorous acid, so that the detection of the hypochlorous acid is facilitated.

(6) Simple synthesis

The hypochlorous acid fluorescent probe is simple to synthesize and is beneficial to commercial popularization and application.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without any creative effort.

FIG. 1 is a graph showing the response time before and after the probe (5. mu.M) was added to hypochlorous acid (5. mu.M);

FIG. 2(a) is a graph showing fluorescence spectra before and after adding hypochlorous acid (0 to 30. mu.M) to the probe (5. mu.M), (b) is a graph showing a linear relationship between the fluorescence intensity at 535nm of the probe (5. mu.M) and hypochlorous acid (0 to 1. mu.M);

FIG. 3 is a graph showing the effect of different ion analytes (all 100. mu.M except where specifically indicated) on the fluorescence intensity of probes (5. mu.M);

FIG. 4 is a chart showing the toxicity test of HeLa cells according to the concentration of each probe, wherein the concentrations are as follows: 0 μ M, 10 μ M, 20 μ M;

FIG. 5(A) is an image of the cell image of the probe (10M) for each cell, and (B) is a histogram of the fluorescence intensity of the probe (10. mu.M) for each cell;

FIG. 6 is a cytogram and a fluorescence intensity histogram of probes (5. mu.M) detecting endogenous and exogenous hypochlorous acid in HeLa cells;

FIG. 7 is an image and a histogram of fluorescence intensity of the coenzyme R inhibition experiment cell of the probe (10. mu.M).

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and should not be used to limit the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

EXAMPLE 1 Synthesis of Compound of formula (II)

The synthetic route is as follows:

the specific operation steps are as follows:

embodiment 1: dissolving the compound (VII) (822mg, 3mmol), p-aminophenol (981mg, 9mmol) and cesium carbonate (2931mg, 9mmol) in 60mL of acetonitrile solution, heating and refluxing for 3 hours, obtaining a solid through suction filtration under reduced pressure after the reaction is finished, washing the solid with dichloromethane to obtain a filtrate, and obtaining a crude product of the compound (VIII) through rotary evaporation under reduced pressure. The crude product was further separated by column chromatography using a mixed system of dichloromethane and methanol (V/V50: 1) as eluent to give 729mg of compound of formula (viii) in 70% pure form.

Embodiment 2: dissolving the compound (VII) (822mg, 3mmol), p-aminophenol (981mg, 9mmol) and cesium carbonate (2931mg, 9mmol) in 120mL of acetonitrile solution, heating and refluxing for 3 hours, obtaining a solid through suction filtration under reduced pressure after the reaction is finished, washing the solid with dichloromethane to obtain a filtrate, and obtaining a crude product of the compound (VIII) through rotary evaporation under reduced pressure. The crude product was further separated by column chromatography using a mixed system of dichloromethane and methanol (V/V50: 1) as eluent to give 606mg of the compound of formula (viii) in 58% yield in pure form.

Embodiment 3: the compound of formula (VII) (822mg, 3mmol), p-aminophenol (981mg, 9mmol) and cesium carbonate (1956mg, 6mmol) were dissolved in 60mL of acetonitrile solution, and heated under reflux for 3 hours, after the reaction was completed, a solid was obtained by suction filtration under reduced pressure, and the solid was washed with dichloromethane to obtain a filtrate, and the filtrate was rotary evaporated under reduced pressure to obtain a crude product of the compound of formula (VIII). The crude product was further separated by column chromatography using a mixed system of dichloromethane and methanol (V/V ═ 50:1) as eluent to give 663mg of the compound of formula (viii) in 64% yield in pure form.

Embodiment 4: dissolving the compound (VII) (822mg, 3mmol), p-aminophenol (654mg, 6mmol) and cesium carbonate (2931mg, 9mmol) in 120mL of acetonitrile solution, heating and refluxing for 3 hours, obtaining a solid through suction filtration under reduced pressure after the reaction is finished, washing the solid with dichloromethane to obtain a filtrate, and obtaining a crude product of the compound (VIII) through rotary evaporation under reduced pressure. The crude product was further separated by column chromatography using a mixed system of dichloromethane and methanol (V/V50: 1) as eluent to give 411mg of the compound of formula (viii) in pure form in 39.5% yield.

The specific operation steps are as follows:

embodiment 1: the compound of the formula (VIII) synthesized in the first step (347mg, 1mmol) was dissolved in 15mL of an anhydrous dichloromethane solution, 15mL of a solution of the compound of the formula (IX) (488mg, 2mmol) and 4-Dimethylaminopyridine (DMAP) (244mg, 2mmol) in anhydrous N, N-Dimethylformamide (DMF) was added, and finally Dicyclohexylcarbodiimide (DCC) (412mg, 2mmol) was added, and the whole reaction system was stirred at room temperature for 15 hours. After the reaction is finished, carrying out reduced pressure rotary evaporation to remove dichloromethane, then adding water to precipitate and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (II). The crude product was further separated by column chromatography with a mixture of dichloromethane and methanol as eluent to give 344mg of pure dark yellow colour in about 60% yield.

Embodiment 2: the compound of the formula (VIII) synthesized in the first step (347mg, 1mmol) was dissolved in 15mL of an anhydrous dichloromethane solution, 15mL of a solution of the compound of the formula (IX) (488mg, 2mmol) and 4-Dimethylaminopyridine (DMAP) (122mg, 1mmol) in anhydrous N, N-Dimethylformamide (DMF) was added, and finally Dicyclohexylcarbodiimide (DCC) (206mg, 1mmol) was added, and the whole reaction system was stirred at room temperature for 15 hours. After the reaction is finished, carrying out reduced pressure rotary evaporation to remove dichloromethane, then adding water to precipitate and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (II). The crude product was further separated by column chromatography with a mixture of dichloromethane and methanol as eluent to give 302mg of pure dark yellow colour with a yield of about 53%.

Embodiment 3: the compound of the formula (VIII) synthesized in the first step (347mg, 1mmol) was dissolved in 15mL of an anhydrous dichloromethane solution, 15mL of a solution of the compound of the formula (IX) (244mg, 1mmol) and 4-Dimethylaminopyridine (DMAP) (122mg, 1mmol) in anhydrous N, N-Dimethylformamide (DMF) was added, and finally Dicyclohexylcarbodiimide (DCC) (206mg, 1mmol) was added, and the whole reaction system was stirred at room temperature for 15 hours. After the reaction is finished, carrying out reduced pressure rotary evaporation to remove dichloromethane, then adding water to precipitate and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (II). The crude product was further separated by column chromatography with a mixture of dichloromethane and methanol as eluent to give 248mg of pure dark yellow colour with a yield of about 43%.

Embodiment 4: the compound of the formula (VIII) synthesized in the first step (694mg, 2mmol) was dissolved in 15mL of an anhydrous dichloromethane solution, 15mL of a solution of the compound of the formula (IX) (488mg, 2mmol) and 4-Dimethylaminopyridine (DMAP) (244mg, 2mmol) in anhydrous N, N-Dimethylformamide (DMF) was added, and finally Dicyclohexylcarbodiimide (DCC) (412mg, 2mmol) was added, and the whole reaction system was stirred at normal temperature for 15 hours. After the reaction is finished, carrying out reduced pressure rotary evaporation to remove dichloromethane, then adding water to precipitate and fix, and finally carrying out suction filtration to obtain a solid product, thereby obtaining a crude product containing the compound of the formula (II). The crude product was further separated by column chromatography with a mixture of dichloromethane and methanol as eluent to give 322mg of pure dark yellow colour in about 28% yield.

Example 2: testing time dynamics of fluorescent probes

A10 mL test system with a probe concentration of 5 μ M was prepared, then 5 μ M hypochlorous acid was added to the test system, and the change in fluorescence intensity was measured by a fluorescence spectrometer immediately after shaking uniformly. The above measurement was carried out in a PBS buffer solution (10mMPBS, pH7.4) system, the probe used was the probe prepared in example 1, and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 1, the fluorescence intensity instantaneously reached a maximum value and remained constant after the addition of hypochlorous acid, indicating that the probe instantaneously responded to hypochlorous acid, providing a rapid analysis method for the determination of hypochlorous acid.

Example 3: testing the concentration gradient of fluorescent probes to hypochlorous acid

A plurality of parallel samples with the probe concentration of 5 mu M are arranged in a 10mL colorimetric tube, then hypochlorous acid with different concentrations is added into a test system, and the change of the fluorescence intensity of the samples is tested by a fluorescence spectrometer after the samples are uniformly shaken. The above measurement was carried out in a PBS buffer solution (10mMPBS, pH7.4) system, the probe used was the probe prepared in example 1, and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 2(a), the fluorescence intensity at 553nm gradually increased with the increase in the hypochlorous acid concentration. Also, it can be seen from FIG. 2(b) that the probe (5. mu.M) shows a good linear relationship between the fluorescence intensity at 560nm and the hypochlorous acid concentration after the probe is added with hypochlorous acid (0 to 1. mu.M), which demonstrates that the hypochlorous acid can be quantitatively analyzed by means of the fluorescent probe.

Example 4: testing the selectivity of fluorescent probes

A plurality of parallel samples with a probe concentration of 5 mu M are arranged in a 10mL colorimetric tube, then different analytes (the analytes are blank, potassium ion, calcium ion, sodium ion, magnesium ion, zinc ion, ferric ion, ferrous ion, copper ion, fluorine ion, iodine ion, chloride ion, bromide ion, nitrate ion, nitrite, carbonate, sulfate radical, cysteine (Cys), homocysteine (Hcy), Glutathione (GSH), sulfide ion, hydrogen peroxide, tert-butyl peroxide free radical, hydroxyl free radical, superoxide anion, singlet oxygen, nitric oxide and hypochlorous acid, except for special marks, the concentration of other analytes is 100 mu M, the concentration of Cys and Hcy is 500 mu M, and the concentration of hypochlorous acid is 5 mu M) are added into the test system, and the fluorescence intensity change of the analytes is tested by a fluorescence spectrometer after shaking uniformly. The above measurement was carried out in a PBS buffer solution (10mMPBS, pH7.4) system, the probe used was the probe prepared in example 1, and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 3, only the addition of hypochlorous acid caused a strong change in the fluorescence intensity of the probe, while the effect of other analytes was almost negligible. Experiments prove that the probe has higher selectivity on hypochlorous acid and is beneficial to the detection and analysis of hypochlorous acid.

Example 6: toxicity test of fluorescent probe on HeLa cells

Cytotoxicity of probes at different concentrations on HeLa cells was determined using a cell counting kit (CCK-8). The probe concentrations were 0. mu.M, 10. mu.M, 20. mu.M, respectively, and the time for probe incubation of the cells was 4 h.

As is clear from FIG. 5, the probe has the characteristic of low toxicity, and can be applied to real-time detection of hypochlorous acid in a cell sample for a long time.

Example 6 fluorescent Probe cell screening assay

Two normal cells and four groups of cancer cells (normal cells: RAW264.7 and HUVEC; cancer cells: MGC-803, HeLa, HepG2 and SH-SY5Y) were incubated with probes (10. mu.M) for 25min, and finally six groups of cells were subjected to confocal microscopy. (A) Is a cytographic image of various cells. (B) Is a histogram of fluorescence intensity of 6 cells.

As is clear from FIG. 5, cancer cells and normal cells incubated with the probe exhibited different fluorescence intensities, and the fluorescence intensity of cancer cells was significantly higher than that of normal cells. Experiments prove that the probe has the function of distinguishing cancer cells from normal cells.

Example 7 fluorescence microscopy imaging of fluorescent probes for exogenous and endogenous hypochlorous acid in HeLa cells

Dividing the HeLa cells into five groups, using the group a as a control group, and carrying out no operation; group b was incubated with probe (10. mu.M) for 25 min; group c, incubation of HOCl (10 μ M) for 25min on the basis of group b cells; d groups are firstWith LPS (1.0. mu.g mL)^-1LPS is an inflammation stimulator capable of stimulating cells to produce HOCl) for 2h, and then incubating with probe (10 μ M) for 25 min; group e was first treated with NAC (500. mu.M, NAC acts in contrast to LPS, and is a ROS scavenger that eliminates HOCl produced by the cells) for 3h, and incubated with probe (10. mu.M) for 25 min. Finally, confocal microscopy imaging was performed on each of the five groups of cells, wherein (f) represents a histogram of the fluorescence intensity of the cells.

As is clear from FIG. 6, the probe can detect endogenous and exogenous hypochlorous acid in HeLa. Experiments prove that the probe can be applied to hypochlorous acid detection in a biological sample.

Example 8: inhibition assay for fluorescent probes

The HeLa cells were divided into three groups, group a, as a control group, without any manipulation; group b, after 25 minutes of pretreatment with the coenzyme R (50. mu.M), incubated with the probe (10. mu.M) for 25 minutes; c) the method comprises the following steps Incubate with probe (10. mu.M) for 25 min. Finally, confocal microscopy imaging is carried out on the three cells respectively, wherein the graph d is a histogram of the fluorescence intensity of the cells.

As is clear from FIG. 7, the concentration of the probe enriched in the cells was reduced due to the inhibitory effect of coenzyme R. Experiments prove that the introduction of biotin can enable the probe to be more enriched in cancer cells, thereby being beneficial to realizing the function of distinguishing the cancer cells from normal cells.

Although the invention has been described with respect to the above embodiments, it will be understood that further modifications and variations of the present invention are possible without departing from the spirit of the invention and are within the scope of the invention.