A fluorescent dye probe for occult blood detection, and a preparation method and application thereof

Abstract

The present application relates to a kind of occult blood detection fluorescent dye probe and its preparation method and application, the core chemical structure formula of the probe is as shown below:Wherein, Dye is fluorescent dye chromophore, L is alkane chain or aromatic chain.Using the functional fluorescent dye probe molecule described in the present application, hemoglobin in occult blood can be selectively dyed, and then various waveband light sources and single-lens reflex cameras are used for excitation, so that occult blood on the surface of various objects can be visualized by dyeing and exciting with light of different emission wavebands, and high-definition occult blood fluorescence images are obtained.Compared with the prior art, the selected fluorescent dye chromophore skeleton has very low toxicity, ensuring the biological safety and low toxicity of the reagent, and not interfering with subsequent DNA detection.

Description

Technical Field

[0001] This invention relates to the field of molecular fluorescent probes, and more particularly to a fluorescent dye probe for detecting occult blood, its preparation method, and its application. Background Technology

[0002] With the continuous advancement of science and technology, bloodstain detection technology has also made significant progress, from initial microscopic examination to modern DNA analysis techniques, greatly improving both detection methods and accuracy. Bloodstain detection is an important aspect of forensic medicine.

[0003] Spectroscopic techniques are a highly effective method for bloodstain detection, including ultraviolet, visible, and infrared spectroscopy. Ultraviolet light causes hemoglobin in blood to fluoresce. Visible and infrared spectroscopy improve detection accuracy by analyzing different wavelengths reflected or absorbed by bloodstains. However, this technique has high requirements for samples, requiring relatively pure blood. Environmental conditions significantly affect test results, and professionally trained operators are also necessary.

[0004] Several mature methods exist for visualizing occult blood, among which chemical enhancement using developing agents is one of the most common and effective. The main principle of chemical development is to utilize special chemical reagents to specifically bind with specific components in bloodstains, such as amino acids, lipids, DNA, or antigens, to identify the bloodstains. Changes in color or fluorescence signals before and after binding are used to reveal the bloodstain. Fluorescence development, in particular, due to its high sensitivity, provides clearer bloodstain patterns compared to color development. Chemical development methods include redox reaction development, protein staining development, and amino acid reaction development.

[0005] Redox revealing methods utilize the redox reaction between reagents and blood components. Fresh blood contains catalase, while older blood contains ferrous hematoporphyrin, which also possesses catalase activity. The reaction of catalase, hematoporphyrin, and hydrogen peroxide causes the hydrogen peroxide to release singlet oxygen, a highly oxidizing agent. This oxygen oxidizes leaching substances into a specific color, thus revealing latent bloodstains. Examples include tetramethylbenzidine-enhanced revealing, luminol-enhanced revealing, colorless crystal violet-enhanced revealing, and colorless malachite green-enhanced revealing. These methods rely on catalase and hematoporphyrin catalyzing the release of atomic oxygen from hydrogen peroxide, oxidizing leaching substances into chromogenic substances and revealing latent bloodstains. Luminol is the most widely used reagent. As a hypothetical test for bloodstain detection, luminol has been used in forensic medicine for over 40 years. It is considered a highly sensitive reagent capable of detecting latent bloodstains, even those that are old. It can also be used to investigate large surfaces. Studies have also shown that DNA can be extracted from bloodstains after luminol treatment, and then analyzed using polymerase chain reaction (PCR). While luminol reagent is widely used for bloodstain detection, it also has certain operational limitations. For example, due to its light sensitivity, the luminol reaction must be observed under the darkest possible conditions. Furthermore, the oxidation of luminol is a rapid and irreversible reaction, so users must act quickly to observe and capture images, otherwise, the image will be lost.

[0006] Protein staining and development methods utilize the amphoteric nature of proteins, allowing them to bind to either the cations or anions in certain staining agents, thus staining the proteins. Acidic staining agents generate positively charged cations, making them negatively charged anions, which then bind to the positively charged amino groups in proteins, thus staining them. These staining agents are generally used to stain cytoplasm, such as Amine Black, Acid Yellow, and Coomassie Brilliant Blue. Basic staining agents generate negatively charged anions, making them positively charged cations, which then bind to the negatively charged carboxyl groups in proteins, thus staining them, such as Brilliant Green. However, these reagents also have limitations. For example, Amine Black cannot destain on permeable substrates, so it is suitable for non-permeable, light-colored substrates, and it can affect the DNA detection of bloodstains after development. Acid Yellow is a very convenient and widely used reagent for developing occult blood stains, as it does not damage DNA in the blood, but the procedure is more complex.

[0007] Amino acid reaction development utilizes the fact that amino acids are colorless crystals with melting points above 230℃. When melted, they decompose and release CO2. They are soluble in both strong acids and strong alkalis, forming salts with both acids and alkalis. Thus, amino acids in blood can react with certain acidic or alkaline reagents to produce colored substances, thereby revealing occult blood fingerprints. However, this method requires specific temperature and humidity conditions, making it extremely inconvenient for general crime scene investigations. It is primarily used in laboratory testing to enhance the development of occult blood fingerprints. Common reagents include ninhydrin and 1,8-diafluorene-9-one (DFO). However, when using ninhydrin in practice, the sample must be heated, and attention must be paid to the surrounding environment. Prepared ninhydrin solutions should not be left for extended periods; the development effect will deteriorate after two weeks. The pale purple-red compound formed by the reaction of DFO with amino acids exhibits strong visible fluorescence when excited by a blue-green light source in the 540nm-570nm range. However, it is also limited by the fact that the reaction requires heating, making it inconvenient for field use.

[0008] While traditional chemical reagents have shown good performance in enhancing blood fingerprints, and some are considered less harmful to DNA patterns in blood, several drawbacks remain to be overcome: (1) Most chemical reagents are non-fluorescent, which may reduce the visibility of ridges on multicolored or complex background surfaces; (2) Hydrogen peroxide-based methods targeting heme groups often result in unclear bloodstain textures due to oxidation reactions in air and the strict controllability of hydrogen peroxide concentration; (3) Most chemical reagents involve cumbersome handling or contain toxic components, making them less user-friendly for on-site operators. Therefore, it is necessary to develop new technologies with higher contrast, more color options, and more user-friendly operation.

[0009] In recent years, based on continuous theoretical and technological breakthroughs in nanomaterials, biotechnology, and fluorescent luminescent materials research, research groups both domestically and internationally have begun to utilize their accumulated technologies in these fields to develop a new round of chemical reagents for revealing latent blood fingerprints. For example, many inorganic nanomaterials possess inherent protein amino affinity, multifunctional surface functionalization, abundant color alternatives, and excellent optical properties, making them promising blood fingerprint enhancement agents. Emerging organic materials incorporating aggregation-induced emission materials (AIEgens) and conjugated polyelectrolytes (CPEs) have also been widely reported in recent years as ideal fluorescent markers for potential blood fingerprints. Immunoreactive reagents (IRRs), which detect specific substances in blood fingerprints through antibody-antigen immunoreactions, thus revealing blood against this background, also exhibit good anti-background interference imaging capabilities. While the design and synthesis of these reagents have facilitated the development of chemical reagents for developing occult blood, several problems remain: 1) Most fluorescent staining reagents require repeated washing after use to clearly reveal the bloodstain patterns; 2) Many reagents exhibit false positives; 3) Nanomaterials and other materials are prone to aggregation, resulting in reagents that cannot be stored for extended periods; 4) Some reagents still require a high proportion of organic solvents for solubilization, leading to significant toxicity. To date, no new, highly efficient, accurate, and convenient fluorescent compounds for occult blood staining have been reported. Summary of the Invention

[0010] The purpose of this invention is to overcome the defects of the prior art and provide a fluorescent dye probe for occult blood detection, its preparation method, and its application, which meet the requirements of efficient, accurate, and low-toxicity occult blood staining reagents.

[0011] The objective of this invention can be achieved through the following technical solutions:

[0012] To address the shortcomings of existing technologies and the need for new, rapid, efficient, and low-toxicity occult blood staining reagents, this invention provides a probe molecule based on the chromophore framework structure of a fluorescent dye for the application of occult blood imaging. This fluorescent dye probe exhibits high biocompatibility and can rapidly (within 30 seconds) and efficiently develop fluorescence in aqueous solutions for occult blood on various subjects. Furthermore, by modifying the fluorescent chromophore framework, this invention can provide staining reagents with excitation and emission wavelengths covering the entire range of 350-1200 nm. Further, the innovation of this structure lies in utilizing the molecular rotational structure of the fluorescent dye chromophore framework itself. The rapid twisting of this framework in aqueous solution allows the designed chromogenic reagent to maintain a fluorescent "dark state" before the aqueous solution comes into contact with the bloodstain area. Once the bloodstain is detected, the twisting is inhibited, converting it to a fluorescent "bright state," thereby achieving efficient "off-on" fluorescence imaging of occult blood, as detailed below:

[0013] One aspect of the present invention provides a fluorescent dye probe for detecting occult blood, the chemical structure of which is shown below:

[0014]

[0015] Where Dye is the chromophore of the fluorescent dye, and L is an alkane chain or an aromatic chain.

[0016] n1 is 0 to 6; n2 is 1 to 6; n3 is 1 to 6; R1 and R2 are each independently one or more of hydrogen, alkyl, hydroxyl, carboxyl or amino groups.

[0017] Furthermore, the Dye is selected from one or more of the following: imidazolinone, coumarin, bipyridine, squaric acid cyanine, 1,8-naphthylimide, phenanthrene, o-phenanthroline, anthracene, oxanthracene, halogenated benzoyl peroxide, cresol purple, pyrene, perylene, tetraphenylethylene, triphenylmethane, fluorescein, rhodamine, BODIPY, methylene blue, benzobisthiadiazole, hemicyanine, cyanine, or indocyanine green, as detailed below:

[0018]

[0019]

[0020] Wherein, n is 1 to 10; R3 to R5 are each independently one or more of hydrogen, alkyl, hydroxyl, carboxyl or amino groups.

[0021] All the connection sites of the Dye can be connected to R1 and L.

[0022] Furthermore, the L is selected from one or more of benzene ring, naphthalene ring, thiophene, indole, aniline, diphenylamine, triphenylamine, carbazole, or fluorene, as specifically as follows:

[0023]

[0024] Where n is 1 to 5; all the connection sites of L can be connected to R2, L and SO3-.

[0025] Furthermore, each of R1 to R5 is independently one or more of hydrogen, alkyl, hydroxyl, carboxyl, or amino groups, as detailed below:

[0026]

[0027] Where n is 1 to 10, and R6, R7, and R8 are alkyl or aromatic ring structural groups.

[0028] The second aspect of this invention provides a method for preparing the fluorescent dye probe for detecting occult blood, comprising the following steps:

[0029] S1: In a reactor, N-acetylglycine, aromatic aldehyde, sodium acetate and acetic anhydride were added respectively, and the reaction was refluxed under nitrogen protection. After the reaction, the mixture was cooled until solid precipitated, then the anhydride was washed away, filtered, and then washed with cold ethanol. After drying, compound A was obtained.

[0030] S2: In the reactor, compound A and R3 amine obtained in step S1 are added respectively, and then solvent is added to cover the solid. The reaction is refluxed under nitrogen protection. After the reaction, the mixture is cooled, the solvent is removed under reduced pressure, and compound B, i.e., the fluorescent dye probe for occult blood detection, is obtained.

[0031] S3: In the reactor, add compound B, aldehyde and zinc chloride as described in step S2 respectively, and then add solvent to cover the solid. Reflux the reaction under nitrogen protection. After the reaction, cool and remove the solvent under reduced pressure. After separation, the fluorescent dye probe for occult blood detection is obtained.

[0032] Further, the molar ratio of N-acetylglycine, aromatic aldehyde, sodium acetate and acetic anhydride in step S1 is (1.0-1.2):1:(1.2-1.5):(10-15); the molar ratio of compound A and R3 amine in step S2 is 1:(1.5-2.0); and the molar ratio of compound B, aldehyde and zinc chloride in step S3 is 1:(1.0-1.5):(5-10).

[0033] Furthermore, the R3 amine has a structure in which an amino group is attached to an R3 group.

[0034] Furthermore, in step S1, n-hexane is used to wash away the acid anhydride.

[0035] Furthermore, in step S2, in addition to adding compound A and amine obtained in step S1, potassium carbonate or pyridine is added.

[0036] Preferably, the reaction is refluxed overnight in step S2.

[0037] Furthermore, in steps S1 and S3, the reflux reaction time is 4-12 hours.

[0038] The third aspect of this invention provides the application of the fluorescent dye probe for detecting occult blood, wherein the probe is applied in occult blood fluorescence imaging, specifically including the following operational steps:

[0039] A. By contacting the solution containing the fluorescent dye probe with the carrier containing occult blood, the structural vibration of the fluorescent dye probe is suppressed after it is targeted to the occult blood region.

[0040] For example, the solution containing the fluorescent dye probe is dropped onto a carrier containing potential bloodstains, or the solution containing the fluorescent dye probe is sprayed onto a carrier containing potential bloodstains, so that the solution of the fluorescent dye probe comes into contact with the carrier containing latent blood.

[0041] For example, by placing a solution containing the fluorescent dye probe in a small atomizer, the solution containing the fluorescent dye probe is atomized and sprayed onto a carrier containing potential bloodstains, so that the solution of the fluorescent dye probe comes into contact with the carrier containing potential bloodstains, thereby achieving the purpose of developing the bloodstain area.

[0042] The solution for the fluorescent dye probe is a solution obtained by dissolving the fluorescent dye in a solvent, wherein the solvent is deionized water, an organic solvent, or a mixed solvent, preferably an aqueous solution.

[0043] B. Under the illumination of excitation light, the fluorescent dye probe emits emission light, realizing fluorescence imaging of occult blood.

[0044] Furthermore, the concentration of the solution is 0.1 μmol / L to 10 mol / L.

[0045] Furthermore, the concentration of the solution is preferably 30 μmol / L to 2 mol / L.

[0046] Furthermore, the wavelengths of the excitation light and the emission light are 350-1200 nm.

[0047] Furthermore, the wavelength of the excitation light is preferably 405-633 nm, and the wavelength of the emitted light is preferably 500-1200 nm.

[0048] Furthermore, the fluorescent dye probe is left on the occult blood for 5 seconds to 5 minutes before being irradiated with excitation light.

[0049] Furthermore, the preferred time for the fluorescent dye probe to remain on the latent blood is 10-60 seconds. After a period of time, irradiation with excitation light can make the latent bloodstains on the object surface show brighter fluorescence. With the help of a regular SLR camera, it is easier and more direct to obtain latent blood fluorescence imaging with low background noise, high brightness, and high definition.

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] (1) This invention utilizes fluorescent dye probes to enable rapid and portable imaging of potential bloodstains; it provides clear imaging of potential bloodstains without affecting or damaging them. There is almost no background fluorescence under excitation light. In other words, this invention allows for simple operation against different colored backgrounds to obtain clear and easily identifiable fluorescent images of bloodstains.

[0052] (2) The application of the functional fluorescent dye probe based on the fluorescent dye chromophore skeleton provided by the present invention in the detection of occult blood; through the two conjugated connection points of Dye and Ar, the conjugated system can be expanded to provide dyes with different excitation and emission wavelengths from visible light to near infrared; at the same time, the added sulfonic acid group can connect various substances that can interact with the occult blood region to achieve the purpose of specific detection of occult blood.

[0053] (3) Based on the rapid torsion of the chromophore skeleton of the fluorescent dye in the aqueous solution, the designed chromogenic reagent maintains a fluorescent "dark state" before the aqueous solution comes into contact with the bloodstain area, and once the bloodstain area is identified, the torsion inhibition is converted into a fluorescent "bright state", thereby achieving efficient "off-on" fluorescence imaging for occult blood.

[0054] (4) The selected fluorescent dye chromophore backbone has very low toxicity. This ensures the biosafety and low toxicity of the reagents and prevents interference with subsequent DNA detection. Attached Figure Description

[0055] Figure 1 This is a schematic diagram illustrating the staining effect of LB-Red prepared in Example 1 on occult blood on different subjects;

[0056] Figure 2 This is a schematic diagram of the occult blood color development effect of LB-Red fluorescent dye probes of different concentrations on a ceramic substrate in Example 1. Detailed Implementation

[0057] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0058] A fluorescent dye probe for detecting occult blood, the chemical structure of which is shown below:

[0059]

[0060] Where Dye is the chromophore of the fluorescent dye, and L is an alkane chain or an aromatic chain.

[0061] n1 is 0 to 6; n2 is 1 to 6; n3 is 1 to 6; R1 and R2 are each independently one or more of hydrogen, alkyl, hydroxyl, carboxyl or amino groups.

[0062] In some embodiments, Dye is a fluorescent dye chromophore including one or more of the following: imidazolinone, coumarin, bipyridine, squaric acid cyanine, 1,8-naphthalimide, phenanthrene, o-phenanthroline, anthracene, oxanthracene, halogenated cresol violet, pyrene, perylene, tetraphenylethylene, triphenylmethane, fluorescein, rhodamine, BODIPY, methylene blue, benzobisthiadiazole, hemicyanine, cyanine, or indocyanine green series dyes and their derivatives. Some fluorescent dye structures are as follows:

[0063]

[0064] Wherein, n is 1 to 10; R3 to R5 are each independently one or more of hydrogen, alkyl, hydroxyl, carboxyl or amino groups.

[0065] All the connection sites of the Dye can be connected to R1 and L.

[0066] In some embodiments, L is an alkane chain or aromatic chain, comprising one or more of the following groups: benzene ring, naphthalene ring, thiophene, indole, aniline, diphenylamine, triphenylamine, carbazole, or fluorene, with partial structures as follows:

[0067]

[0068] Where n is 1 to 5; all the connection sites of L can be connected to R2, L and SO3-.

[0069] In some embodiments, R1 to R5 are each independently one or more of hydrogen, alkyl, hydroxyl, carboxyl, or amino groups, as detailed below:

[0070]

[0071] Where n is 1 to 10, and R6, R7, and R8 are alkyl or aromatic ring structural groups.

[0072] The preparation method of the fluorescent dye probe for occult blood detection described above is similar to that of LB-Red in this embodiment. When the same or similar methods are used for bloodstain imaging, good bloodstain imaging results can also be obtained.

[0073] The application of the fluorescent dye probe for occult blood detection, as described above, involves the following steps in occult blood fluorescence imaging:

[0074] A. Contact the solution containing the fluorescent dye probe with the carrier containing occult blood, so that the structural vibration of the fluorescent dye probe is suppressed after it is targeted to the occult blood region; the concentration of the solution is 0.1μmol / L-10mol / L, preferably 30μmol / L-2mol / L; at high concentrations, the dye dissolves poorly, so it can be placed in an ultrasonic cleaner for ultrasonic mixing to help dissolve until the solution is clear and transparent.

[0075] For example, the solution containing the fluorescent dye probe is dropped onto a carrier containing potential bloodstains, or the solution containing the fluorescent dye probe is sprayed onto a carrier containing potential bloodstains, so that the solution of the fluorescent dye probe comes into contact with the carrier containing latent blood.

[0076] For example, by placing a solution containing the fluorescent dye probe in a small nebulizer, the solution containing the fluorescent dye probe is atomized and sprayed onto a carrier containing potential bloodstains, so that the solution of the fluorescent dye probe comes into contact with the carrier containing potential bloodstains, thereby achieving the purpose of color development.

[0077] The solution for the fluorescent dye probe is a solution obtained by dissolving the fluorescent dye in a solvent, wherein the solvent is deionized water, an organic solvent, or a mixed solvent, preferably an aqueous solution.

[0078] B. Under excitation light, such as by irradiating the object with an LED lamp of a certain wavelength or a low-power (5W) laser, the fluorescent dye probe emits emission light, achieving fluorescence imaging of latent blood. The wavelengths of the excitation and emission light are 350-1200nm, preferably 405-633nm for the excitation light and 500-1200nm for the emission light. Before irradiation with excitation light, the fluorescent dye probe can remain on the latent blood for 5s-5min, preferably 10-60s for color development. After a period of time, irradiation with excitation light can make the latent bloodstains on the object surface show brighter fluorescence. Then, using a regular SLR camera, it is easier and more direct to obtain low background noise, high brightness, and high definition fluorescent bloodstain images, and clearer bloodstains can be recorded.

[0079] Example 1

[0080] Synthesis of the fluorescent dye probe LB-Red:

[0081] S1: Preparation of the first compound

[0082]

[0083] p-Dimethylaminobenzaldehyde (0.75 g, 5.00 mmol), N-acetylglycine (0.64 g, 5.50 mmol), and sodium acetate (0.62 g, 7.50 mmol) were dissolved in acetic anhydride (5 mL). The reaction mixture was heated to 110 °C under a nitrogen atmosphere and refluxed for 5 h. After the reaction was complete, the solvent was removed while hot using a rotary evaporator under reduced pressure, and the reaction mixture was ultrasonically washed three times with 20 mL of n-hexane. The precipitate was then transferred to a Buchner funnel and washed with ice-cold ethanol to obtain the solid. The product was then dried overnight in a vacuum oven at 55 °C to give the first compound as a deep red solid (1.15 g, 68%). The purity of this product was sufficient for the next synthesis. 1 H NMR (400MHz, CDCl3) δ7.99 (d, J = 8.8 Hz, 2H), 7.08 (s, 1H), 6.70 (d, J = 9.2 Hz, 2H), 3.07 (s, 6H), 2.36 (s, 3H). 13 C NMR (101MHz, CDCl3) δ168.86,162.96,152.19,134.53,132.93,127.70,121.41,111.81,40.16,15.67.

[0084] S2: Preparation of the second compound

[0085]

[0086] The first compound (1.15 g, 5.00 mmol) was dissolved in 20 mL of methylamine ethanol solution (33 wt%) and stirred at room temperature for 2 h. Then, potassium carbonate (1.04 g, 7.5 mmol) was added, and the mixture was stirred and refluxed at 90 °C under nitrogen protection for 10 h. After the reaction was complete, the solvent was removed using a rotary evaporator under reduced pressure, and the mixture was purified by silica gel column chromatography to give a yellow solid (0.68 g, 56%), which was the second compound. 1 H NMR (400MHz, CDCl3) δ 8.03 (d, J = 8.4 Hz, 2H), 7.06 (s, 1H), 6.67 (d, J = 9.2 Hz, 2H), 3.14 (s, 3H), 3.01 (s, 6H), 2.32 (s, 3H). 13 C NMR (101MHz, CDCl3) δ170.79,159.12,151.55,134.22,128.89,122.27,111.80,40.11,26.60,15.64.

[0087] S3: Preparation of compound LB-Red

[0088]

[0089] Disodium benzaldehyde-2,4-disulfonic acid (1.55 g, 5.00 mmol) and the second compound (1.22 g, 5.00 mmol) were dissolved in 1,4-dioxane (20 mL), and ZnCl2 catalyst (3.40 g, 25.00 mmol) was added. The reaction mixture was heated and stirred at 120 °C under nitrogen protection for 7 h. The solvent was removed using a rotary evaporator under reduced pressure, and the product was purified by silica gel column chromatography to give a black solid, which was compound LB-Red (2.17 g, 81%). 1 H NMR (400MHz, DMSO-d6) δ8.45 (s, 1H), 7.92 (d, J = 8Hz, 1H), 7.77 (s, 1H), 7.72-7.70 (m, 2H), 7.64 (d ,J=6Hz,1H),7.03(d,J=16Hz,1H),6.97(s,1H),6.78(d,J=8.2Hz,2H),3.29(s,3H),3.04(s,6H). 13 C NMR(101MHz,DMSO-d6)δ170.29,159.31,152.00,142.20,135.05,133.66,133.15,132 .56,131.50,130.81,130.52,125.35,125.23,124.72,113.13,112.65,40.28,28.17.

[0090] S4: Prepare an aqueous solution of the fluorescent dye probe.

[0091] The fluorescent dye probe is dissolved in a certain amount of aqueous solution to prepare a concentration of 100 μmol / L. The solution can be ultrasonically mixed in an ultrasonic cleaner to accelerate dissolution until it becomes clear and transparent. The prepared dye is then used for subsequent occult blood color development. The dye is the fluorescent dye probe LB-Red of this invention.

[0092] The dye solution was placed in a small atomizer and atomized onto the object bearing the fingerprint for 30 seconds. The object was then irradiated with a low-power (5W) 405nm laser. A camera was used to take a picture through a filter (the filter transmits light with wavelengths above 500nm). A relatively clear image of the bloodstains was obtained. Figure 1 The staining effect of LB-Red on occult blood on different subjects. Figure 2 The diagram shows the color development effect of LB-Red fluorescent dye probes at different concentrations on a ceramic substrate. It can be seen that the color development effect is better as the concentration of LB-Red fluorescent dye probe increases.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A fluorescent dye probe for detecting occult blood, characterized in that, The chemical anionic structure of the probe is shown below: 。 2. The application of the fluorescent dye probe for occult blood detection as described in claim 1 in the preparation of occult blood fluorescence imaging reagents, characterized in that, The method of using this reagent is as follows: A. Contact the solution containing the fluorescent dye probe with the carrier containing blood. B. Under the illumination of excitation light, the fluorescent dye probe emits emission light, realizing fluorescence imaging of occult blood.

3. The application of the fluorescent dye probe for occult blood detection according to claim 2, characterized in that, The concentration of the solution is 0.1 μmol / L-10 mol / L; the wavelengths of the excitation and emission light are 350-1200 nm.

4. The application of the fluorescent dye probe for occult blood detection according to claim 2, characterized in that, Before being irradiated with excitation light, the fluorescent dye probe remains on the occult blood for 5 s-5 min.

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