A multi-target responsive aggregation-induced fluorescent probe, fingerprint developer and its application in fingerprint imaging

Abstract

The present invention belongs to the technical field of new material fluorescent probes, and more specifically, relates to a multi-target response aggregation-induced fluorescent probe, a fingerprint developer and its application in fingerprint imaging. The fluorescent probe has a general structural formula as shown in formula (I): #imgabs0# wherein Ar1, Ar2, Ar3 and Ar4 are each independently an aromatic ring structure with a carbon number of 6-30, R1 and R2 are each independently H or a substituent with a carbon number of 1-30, and at least one of R1 and R2 contains an NHS group. Using the solution of the fluorescent probe of the present invention, with the help of an ordinary camera, the latent fingerprint on the surface of a smooth object can be visualized by dyeing and then exciting with ultraviolet light, so that low background noise, high contrast and high definition fluorescent fingerprint imaging can be obtained more simply and directly.

Description

Technical Field

[0001] The present invention belongs to the technical field of new material fluorescent probes, and more specifically, relates to an aggregation-induced fluorescent probe with multi-target response, a fingerprint developer and applications thereof in fingerprint imaging. Background Art

[0002] Fingerprints are skin lines with special shapes that appear at the end of human fingers and are composed of ridges (convex fingerprint lines) and furrows (concave fingerprint lines). Due to the combined influence of genetic and environmental factors, human fingerprints are different, and fingerprints have the characteristic of being unchanged throughout life if the dermis is not damaged. Fingerprints are highly recognizable to their holders, that is, they are unique and unchanged throughout life. Therefore, in forensic science, the detailed characteristics of fingerprint traces at the crime scene can be analyzed and compared to quickly and accurately identify their holders.

[0003] When fingers touch the surface of the body or other objects, some chemicals will be contaminated on the surface of the fingers. These chemicals include endogenous substances and exogenous substances. Endogenous substances mainly include amino acids, proteins, glucose, lactic acid, urea, oils, fatty acids, cholesterol, etc.; inorganic substances mainly include chloride, sodium hydroxide, iron ions, bicarbonate, etc. Exogenous substances mainly include blood, dirt, cosmetics, food contaminants, moisturizers and hair care products, etc. The chemical composition of exogenous substances fluctuates greatly while the composition of endogenous substances fluctuates less.

[0004] Latent fingerprints are the most frequently seen fingerprints at crime scenes. They are fingerprints left by chemical residues on the surface of ordinary objects when the finger touches the surface. In most cases, the existence of latent fingerprints is relatively hidden and cannot be directly observed by the human eye. Therefore, it is particularly important to develop a method to make latent fingerprints emit fluorescence and obtain latent fingerprint imaging based on the relatively stable chemical components on the surface of latent fingerprint traces.

[0005] Traditional fingerprint imaging methods mainly include powder method, fumigation method and chemical method. However, these methods have many defects. During the imaging process, they will cause irreversible damage to multiple organs of the operator to a large extent, and the clarity and contrast of such imaging are relatively low. Therefore, the emergence of new latent fingerprint fluorescence imaging methods is very necessary. Among them, the latent fingerprint fluorescence imaging method based on the principle of aggregation-induced emission has greatly improved the contrast and clarity of its imaging due to its superior imaging principle.

[0006] At present, the latent fingerprint imaging methods based on aggregation-induced emission (AIE) are mainly powder method and solution method. The powder method has the same unavoidable dust hazard as the traditional powder imaging method. The solution method has many advantages over the powder method, but it still has many defects. For example: 1) The solution ratio adopts a dual or multi-solvent system, which is cumbersome to prepare and not suitable for long-term storage; 2) Solution immersion imaging will cause the loss of fingerprint details; 3) In most existing latent fingerprint imaging methods based on the AIE principle, the fluorescent probe only targets the oily substances in the fingerprint traces for mechanical adsorption or electrostatic adsorption, and the target substance is single; the substances attached to the surface of human fingers are diverse, and the existing fluorescent probe technology based on the AIE principle only targets oily substances for fingerprint imaging, which often has the problem of poor identification accuracy. In fact, latent fingerprint traces contain a variety of stable endogenous substances such as amino acids and lysozyme. It is urgent to propose fluorescent probes that can simultaneously target more types of substances for latent fingerprint imaging to improve identification assurance and accuracy. Summary of the invention

[0007] In view of the defects of the prior art, the present invention provides a multi-target response aggregation-induced fluorescent probe, a fingerprint developer and its application in fingerprint imaging. The probe can produce a targeted reaction to a variety of substances (amino acids and lipid substances, etc.) in latent fingerprint traces. Therefore, the fluorescent probe of the present invention can perform clear and highly recognizable fluorescent imaging of various types of latent fingerprints on the surfaces of various materials. This solves the technical problems of the existing fingerprint collection method, such as high toxicity, low collection efficiency, complex operation, single target substance, low imaging contrast and clarity.

[0008] To achieve the above object, the present invention provides a multi-target responsive aggregation-induced fluorescent probe having a general structural formula as shown in formula (1):

[0009]

[0010] Wherein Ar1, Ar2, Ar3 and Ar4 are each independently an aromatic ring structure with a carbon number of 6-30, R1 and R2 are each independently H, an alkyl group with a carbon number of 1-30, an alkoxy group with a carbon number of 1-30 or an alkyl alcohol with a carbon number of 1-30, and at least one of R1 and R2 contains an NHS group.

[0011] Preferably, Ar1, Ar2, Ar3 and Ar4 are each independently one of the following formulas (II) to (XIV):

[0012]

[0013] Among them, R3 is an alkyl group with a carbon number of 1-8, an amino-terminal alkyl group with a carbon number of 1-8, or a hydroxy-terminal alkyl group with a carbon number of 1-8.

[0014] Preferably, at least one of R1 and R2 is one of the following formulas (15) to (20):

[0015]

[0016] According to another aspect of the present invention, there is provided an application of the aggregation-induced fluorescent probe for latent fingerprint fluorescence imaging.

[0017] Preferably, a solution containing the fluorescent probe is brought into contact with a carrier containing a latent fingerprint, so that the fluorescent probe reacts and combines with the target substance in the fingerprint trace, and finally forms an aggregation state of the probe at the ridge line of the latent fingerprint. Under the excitation of the excitation light source, the excited fluorescent probe molecules decay back to the ground state through radiation and emit fluorescence, thereby realizing fluorescent imaging of the latent fingerprint.

[0018] Preferably, the solution containing the fluorescent probe is dropped onto the carrier containing the latent fingerprint, or the solution containing the fluorescent probe is sprayed onto the carrier containing the latent fingerprint, or the carrier containing the latent fingerprint is immersed in the solution of the fluorescent probe, so that the solution of the fluorescent probe contacts the carrier containing the latent fingerprint.

[0019] Preferably, the solution of the fluorescent probe is an aqueous solution of the fluorescent probe, an organic solution of the fluorescent probe, or a solution obtained by dissolving the fluorescent probe in a mixed solvent.

[0020] Preferably, the concentration of the fluorescent probe in the fluorescent probe solution is 0.1 μmol / L to 2 mol / L, and more preferably 5 μmol / L to 50 μmol / L.

[0021] According to another aspect of the present invention, a latent fingerprint developer is provided, which contains a solution of the aggregation-induced fluorescent probe.

[0022] In general, the above technical solution conceived by the present invention has the following advantages compared with the prior art:

[0023] Beneficial effects:

[0024] (1) The present invention provides an aggregation-induced fluorescent probe with a twisted planar structure based on naphthylimide as the core, which is used for fingerprint fluorescence imaging. The probe can produce a targeted reaction to a variety of substances (amino acids and lipid substances) in latent fingerprint traces. Therefore, the fluorescent probe of the present invention can perform clear and highly recognizable fluorescence imaging of various types of latent fingerprints on the surfaces of various materials. On the one hand, the number of targeted substances increases, the aggregation effect of the fluorescent probe is better, and the fluorescence imaging effect is improved; on the other hand, the number of targeted substances increases. Even if one of them is lost, other target substances can still be targeted, making fingerprint extraction more secure.

[0025] (2) In the solution state, the electron donor part and the acceptor part of the fluorescent probe provided by the present invention freely rotate around the carbon-carbon single bond and double bond, and non-radiative decay occurs, showing weak fluorescence. Since the probe of the present invention aggregates the probe molecules after reacting and combining with its target substance when it contacts the latent fingerprint, the probe is restricted in intramolecular motion, so that the non-radiative decay channel is suppressed, and the excited state fluorescent probe molecules return to the ground state through radiative decay, and emit strong fluorescence.

[0026] (3) The fluorescent probes in the present invention have a targeted binding effect on various substances in latent fingerprint traces. A possible mechanism is that the structure of the fluorescent probes of the present invention contains NHS characteristic groups, which are easy to react chemically with amino acid substances in latent fingerprint traces, thereby gathering on the surface of latent fingerprint ridges; at the same time, since the skeleton structure of the fluorescent probes in the present invention is a hydrophobic structure, when they come into contact with lipid substances on the surface of latent fingerprint traces, they will quickly produce physical adsorption with them, thereby enriching the fluorescent probes on the ridge surface of latent fingerprint traces. The fluorescent probes in the present invention produce targeted binding effects on various substances in latent fingerprint traces through multiple reaction mechanisms, making the imaging of latent fingerprints more secure. The superposition of multiple effects makes latent fingerprint imaging more recognizable.

[0027] (4) The fluorescent probe of the present invention is used for latent fingerprint imaging, which is superior to existing fingerprint collection methods, has higher collection efficiency, is easier to operate, and has lower toxicity. The clarity and contrast of the imaging are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a latent fingerprint staining imaging image of the multi-target aggregation-induced fluorescent probe in Example 1 of the present invention on a tinfoil material background.

[0029] Figure 2 This is a latent fingerprint staining imaging image of the multi-target aggregation-induced fluorescent probe in Example 1 of the present invention on a stainless steel background.

[0030] Figure 3This is a latent fingerprint staining imaging image of the multi-target aggregation-induced fluorescent probe on a plastic material background in Example 1 of the present invention.

[0031] Figure 4 This is a fluorescence response diagram of the multi-target aggregation-induced fluorescent probe on a stainless steel substrate to various substances in fingerprint traces according to Example 1 of the present invention.

[0032] Figure 5 This is a latent fingerprint imaging image of the multi-target aggregation-induced fluorescent probe on a stainless steel substrate according to Example 2 of the present invention.

[0033] Figure 6 This is a latent fingerprint imaging image of the multi-target aggregation-induced fluorescent probe on a stainless steel substrate according to Example 3 of the present invention.

[0034] Figure 7 This is a fluorescence response diagram of the aggregation-induced fluorescent probe on a stainless steel substrate to various substances in fingerprint traces in comparative example 1 of the present invention.

[0035] Figure 8 This is a comparison chart of the ability of the aggregation-induced fluorescent probe of Example 1 of the present invention and Comparative Example 1 to develop fingerprints on a stainless steel plate substrate. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] The present invention provides a multi-target responsive aggregation-induced fluorescent probe having a general structural formula as shown in formula (1):

[0038]

[0039] Wherein Ar1, Ar2, Ar3 and Ar4 are each independently an aromatic ring structure having 6-30 carbon atoms, R1 and R2 are each independently H, an alkyl group having 1-30 carbon atoms, an alkoxy group having 1-30 carbon atoms or an alkyl alcohol having 1-30 carbon atoms; and at least one of R1 and R2 contains an NHS group, which is an N-hydroxysuccinimide (NHS) ester group. Preferably, R1 and R2 are each independently H, an alkyl group having 1-12 carbon atoms, an alkoxy group having 1-12 carbon atoms or an alkyl alcohol having 1-12 carbon atoms, and more preferably H, an alkyl group having 1-8 carbon atoms, an alkoxy group having 1-8 carbon atoms or an alkyl alcohol having 1-8 carbon atoms.

[0040] In some embodiments, Ar1, Ar2, Ar3 and Ar4 are each independently one of the following formulas (II) to (XIV):

[0041]

[0042]

[0043] Among them, R3 is an alkyl group with a carbon number of 1-8, an amino-terminal alkyl group with a carbon number of 1-8, or a hydroxy-terminal alkyl group with a carbon number of 1-8.

[0044] In some embodiments, at least one of R1 and R2 is one of the following formulas (15) to (20):

[0045]

[0046] The aggregation-induced fluorescent probe provided by the present invention can be used for latent fingerprint fluorescent imaging. When the fluorescent probe proposed by the present invention is used for latent fingerprint imaging, it can simultaneously produce a binding effect with lipid substances and amino acid substances on the surface of the latent fingerprint, so that the latent fingerprint emits a relatively strong green fluorescence. Using the solution of such fluorescent probes described in the present invention, with the help of an ordinary SLR camera, the latent fingerprint on the surface of a smooth object can be visualized by dyeing and then exciting it with ultraviolet light or visible light. It is more convenient and direct to obtain fluorescent fingerprint imaging with low background noise, high contrast and high definition.

[0047] The fluorescent probe of the present invention can be prepared by conventional organic synthesis methods according to its structural formula. When the fluorescent probe of the present invention is used for latent fingerprint fluorescence imaging, it can specifically include the following steps:

[0048] A solution containing the fluorescent probe is brought into contact with a carrier containing a latent fingerprint, and the fluorescent probe is aggregated at the ridges of the latent fingerprint by targeted reaction of multiple substances on the surface of the fingerprint trace. Under the illumination of a laser light source, the excited fluorescent probe molecules decay back to the ground state through radiation and emit fluorescence, thereby achieving fluorescent imaging of the latent fingerprint.

[0049] In some embodiments, the solution containing the fluorescent probe is dropped on the carrier containing the latent fingerprint, or the solution containing the fluorescent probe is sprayed on the carrier containing the latent fingerprint, or the carrier containing the latent fingerprint is immersed in the solution of the fluorescent probe, so that the solution of the fluorescent probe is fully in contact with the carrier containing the latent fingerprint.

[0050] The solution of the fluorescent probe of the present invention is a solution obtained by dissolving the fluorescent probe in a solvent. In some embodiments, the solvent is deionized water or an organic solvent or a mixed solvent. In a preferred embodiment, the solution of the fluorescent probe is a solution obtained by dissolving the fluorescent probe in a solvent such as acetonitrile, ethyl acetate, ethanol, methanol dimethyl sulfoxide, isopropanol, isoamyl acetate, etc.

[0051] In some embodiments, the concentration of the fluorescent probe in the fluorescent probe solution is 0.1 μmol / L to 2 mol / L, and more preferably 5 μmol / L to 50 μmol / L.

[0052] In some embodiments, after the fluorescent probes are collected at the ridges of the latent fingerprint, the excess fluorescent probe solution is removed, for example, by using a hair dryer to blow away the residual solution.

[0053] In some embodiments, during the latent fingerprint imaging process, the emission band of the excitation light source used is ultraviolet light or visible light, and the wavelength of the excitation light source is 190 to 520 nanometers, preferably 400 to 470 nanometers. In a preferred embodiment, the use of an excitation light source in the visible light band can avoid damage to the operator's health when using ultraviolet light imaging.

[0054] The aggregation-induced fluorescent probe of the present invention has good properties of aggregation-induced luminescence due to its special molecular structure. Due to the particularity of its structure, the fluorescent probe of the present invention has a targeted response to both amino acids and lipid substances in fingerprint traces, and has many outstanding advantages over existing fluorescent probes with a single targeted substance in fluorescent latent fingerprint imaging.

[0055] By using the fluorescent probe of the present invention and a common SLR camera, the latent fingerprint on the surface of a smooth object can be revealed by soaking the fluorescent probe of the present invention and then exciting it with ultraviolet light, thereby obtaining fluorescent fingerprint imaging with low background noise, high brightness and high definition in a simpler and more direct way.

[0056] The AIE molecules shown in formula (I) provided by the present invention can be directly made into a single solvent solution for use as a latent fingerprint developer, without the need to specifically make a two-phase system AIE ion, and are relatively easier to preserve. Therefore, the present invention also provides a latent fingerprint developer, which includes a solution obtained by dissolving the aggregation-induced fluorescent probe molecules described in the present invention in a solvent. The solvent selected here needs to be able to dissolve the probe molecules, but not dissolve amino acids, and not cause too much damage to oily substances. In some embodiments of the present invention, the solvent is an organic solvent, and preferred organic solvents include acetonitrile, ethyl acetate, ethanol, methanol dimethyl sulfoxide, isopropanol, isoamyl acetate, and the like.

[0057] The multi-targeted AIE fluorescent probe molecules provided by the present invention realize the possible principle of latent fingerprint imaging: when the fluorescent probe molecules dispersed in the solution contact the latent fingerprint traces, one end with the specific group NHS will quickly produce a targeted chemical reaction with the amino acid substances in the fingerprint traces and combine with them; and the fluorescent probe in the present invention has a larger lipophilic skeleton core, and due to the principle of like dissolves like, the probe molecules are quickly physically adsorbed on the surface of lipid substances in the fingerprint traces. Due to the above two reaction mechanisms, the probe molecules are aggregated on the surface of the ridges in the latent fingerprint traces, and further under the excitation of ultraviolet light, the excited state of the fluorescent probe molecules decays back to the ground state through radiation, emitting fluorescence, thereby realizing the fluorescence imaging of the latent fingerprint.

[0058] The present invention uses fluorescent probes to make the operation of latent fingerprint imaging very simple; the latent fingerprint imaging is clear, and no influence or loss is caused on the detailed information of the latent fingerprint. There is almost no background fluorescence under ultraviolet or visible light irradiation. That is, the present invention can obtain clear and highly recognizable fingerprint imaging by simple operation under the collection background of different materials.

[0059] The following are examples:

[0060] Example 1

[0061] First, an acetonitrile solution of the fluorescent probe of this example was prepared with a concentration of 5×10 -5 M. Mix the fluorescent probe and acetonitrile in a glass bottle, and then mix them evenly by ultrasonication until there are no particles visible to the naked eye in the solution. At this point, the fluorescent probe solution for latent fingerprint color detection is prepared. The molecular structure of the fluorescent probe of this embodiment is shown in formula (1), wherein Ar1, Ar2, Ar3 and Ar4 are R1 is R2 is H.

[0062] It can be synthesized by the following method:

[0063] Step 1: Add 1-(4-bromophenyl)-1,2,2-triphenylethylene (1eq), bipyralidin (2eq), potassium acetate (2.5eq) and Pd(dppf)Cl2 (5%) to the reaction flask in sequence, and then add anhydrous dioxane as the reaction solvent. The temperature is slowly raised to 90°C and stirred for 10 hours. After the reaction, the solvent is removed by vacuum concentration. The crude product is purified by column chromatography to obtain white solid compound 1. (Yield 60%).

[0064] Step 2: Add β-alanine (1 eq) and 4-bromo-1,8-naphthalene dicarboxylic anhydride (1 eq) into a reaction flask, then add ethanol as a reaction solvent, and heat under reflux for two hours. After cooling to room temperature, the product precipitates. Filter the product and dry it in a vacuum drying oven to obtain compound 2 as a gray solid (yield 80%).

[0065] Step 3: Compound 2 (1 eq), compound 1 (1.3 eq), K2CO3 (7.5 eq), tetrabutylammonium hydrogen sulfate (10%), and Pd(pph3)4 (20%) were added to the reaction flask in sequence. Then a mixed solution of toluene and water (V / V=2 / 1) was added. Stir at 90°C for 16 hours, the reaction was completed, and the mixture was cooled to room temperature. DCM was used for extraction, the solvent was evaporated under reduced pressure, and the crude product was purified by column chromatography to obtain the reactant 3 as a yellow solid (yield 60%).

[0066] Step 4: Compound 3 (1 eq), 1-hydroxypyridine-2,5-dione (2 eq) and DCC (2 eq) were placed in a reaction flask in sequence. DCM was used as the reaction solvent. The mixture was stirred at room temperature for 12 h, and the reaction was completed. Solid impurities were filtered out. The final product compound was separated and purified by column chromatography to obtain a yellow solid (yield 66%).

[0067] During the latent fingerprint color development test phase, several objects of different materials need to be prepared for pressing fingerprints. These objects of different materials include: tin foil, stainless steel plates, plastic plates, etc. Press the fingerprint on these objects of different materials, and use the fluorescent probe prepared above for latent fingerprint color development detection.

[0068] (1) A solution of several major chemical substances in fingerprint traces was used to draw a special shape on the surface of the stainless steel substrate, and then the stainless steel substrate sample was stained with the prepared probe solution. It was observed that amino acids such as glycine and lysozyme, and lipid substances such as cholesterol and oil all had obvious fluorescence responses to the probe solution, such as Figure 4 shown.

[0069] (2) Testing of tin foil fingerprint samples: First, spread the prepared fluorescent probe solution on the latent fingerprint on the surface of the tin foil. After 20 seconds, blow away the remaining solution and then irradiate with a 405nm ultraviolet lamp. The latent fingerprint ridge will show strong green fluorescence, indicating that the staining is successful. The specific staining effect of tin foil latent fingerprint is as follows: Figure 1 shown.

[0070] (3) Testing of fingerprint samples on stainless steel plates: First, spread the prepared fluorescent probe solution on the latent fingerprints on the surface of the glass plate. After 20 seconds, blow away the remaining solution and then irradiate with a 405nm ultraviolet lamp. Green fluorescence will appear at the ridges of the latent fingerprints, indicating that the staining is successful. The specific staining effect of the latent fingerprint on the glass plate is as follows: Figure 2 shown.

[0071] (4) Testing of plastic plate fingerprint samples: Spread the prepared fluorescent probe all over the fingerprint on the glass plate. After 20 seconds, blow away the remaining solution and then irradiate with a 405nm ultraviolet lamp. Green fluorescence will appear at the ridge of the latent fingerprint, indicating successful dyeing. Figure 3 shown.

[0072] Result analysis:

[0073] Depend on Figure 1 It can be seen that on the tinfoil, the fluorescent imaging of the latent fingerprint is very clear and has a high contrast, which contains some information points of the latent fingerprint, such as the main direction of some ridges (observe the approximate direction of the fingerprint line in the picture), the first-level details of the fingerprint: the main spiral lines; such as the second-level detail features of the fingerprint: the bifurcation points and end points of the ridges and the number of ridges between the feature points; such as the third-level detail features of the fingerprint: the shape of the sweat pores contained in the ridge position in the imaging, etc. After obtaining these 1-3 level detail features of the fingerprint, the fingerprint information can be stored, retrieved, processed and transmitted, and then contacted and exchanged in the fingerprint analysis system database, and personal information can be locked through fingerprint information.

[0074] Depend on Figure 2 It can be seen that clear and complete fingerprint patterns can be seen in the fingerprint sample staining picture of the stainless steel plate obtained by irradiating with 405nm ultraviolet light.

[0075] Depend on Figure 3 After enlarging the picture, you can see clear and complete fingerprint patterns on the plastic plate.

[0076] Depend on Figure 4 It can be observed that both amino acid substances and lipid substances have targeted fluorescence responses to the probe solution.

[0077] Similar to the fluorescent probe molecular structure of this embodiment, for example, R1 is R2 is H, Ar1 is Ar2, Ar3 and Ar4 are each independently When one of the above is used, the preparation method is similar to the fluorescent probe molecular structure of this embodiment. When the same method is used for fingerprint imaging, a better fingerprint imaging effect can also be achieved.

[0078] Example 2

[0079] First, prepare an acetonitrile solution of the dye with a concentration of 5×10 -5 M. Mix the dye and acetonitrile in a glass bottle and then mix them evenly by ultrasonication until there are no particles visible to the naked eye. At this point, the fluorescent probe solution for latent fingerprint color detection is prepared.

[0080] The dye is the fluorescent probe of this embodiment, and its molecular structure is shown in Formula (1), wherein R1 is R2 is H; Ar1 ​​and Ar4 are Ar2 and Ar3 are

[0081] It can be obtained by simple reaction synthesis, and the synthesis steps are as follows:

[0082] Step 1: Add 2,2'-(1-(4-bromophenyl)-2-phenylethylene-1,2-diyl) dinaphthalene (1eq), diboronic acid pinacol ester (2eq), potassium acetate (2.5eq) and Pd(dppf)Cl2 (5%) in the reaction bottle, and then add anhydrous dioxane as the reaction solvent. The temperature is slowly raised to 90°C and stirred for 10h. After the reaction, the solvent is removed by vacuum concentration. The crude product is purified by column chromatography to obtain white solid compound 2-1. (Yield 60%).

[0083] Step 2: Add 3-amino-2-hydroxypropionic acid and 4-bromo-1,8-naphthalene dicarboxylic anhydride (1 eq) into a reaction flask, then add ethanol as a reaction solvent, and heat under reflux for two hours. After cooling to room temperature, the product precipitates. Filter the product and dry it in a vacuum drying oven to obtain compound 2-2 as a gray solid (yield 80%).

[0084] Step 3: Compound 2-2 (1 eq), compound 2-1 (1.3 eq), K2CO3 (7.5 eq), tetrabutylammonium hydrogen sulfate (10%), and Pd(pph3)4 (20%) were added to the reaction flask in sequence. Then a mixed solution of toluene and water (V / V=2 / 1) was added. Stir at 90°C for 16 hours, the reaction was completed, and the mixture was cooled to room temperature. DCM was used for extraction, the solvent was evaporated under reduced pressure, and the crude product was purified by column chromatography to obtain the reactant 2-3 (yield 60%) as a yellow solid.

[0085] Step 4: Compound 2-3 (1 eq), 1-hydroxypyridine-2,5-dione (2 eq) and DCC (2 eq) were placed in a reaction flask in sequence. DCM was used as the reaction solvent. The mixture was stirred at room temperature for 12 h, and the reaction was completed. Solid impurities were filtered out. The final product compound was separated and purified by column chromatography to obtain a yellow solid (yield 60%).

[0086] The fluorescent probe is used for fluorescence imaging detection of latent fingerprints with a stainless steel substrate, and the following results can be obtained: Figure 5 ,As can be seen from the figure, the fingerprint imaging is clear and the ,feature recognition of the fingerprint can reach the third level of details.

[0087] Similar to the fluorescent probe molecular structure of this embodiment, for example, R1 is R2 is H; Ar1 ​​is Ar2, Ar3 and Ar4 are each independently When one of the above is used, the preparation method is similar to the fluorescent probe molecular structure of this embodiment. When the same method is used for fingerprint imaging, a better fingerprint imaging effect can also be achieved.

[0088] Example 3

[0089] First, prepare an acetonitrile solution of the dye with a concentration of 5×10 -5 M. Mix the dye and acetonitrile in a glass bottle and then mix them evenly by ultrasonication until there are no particles visible to the naked eye. At this point, the fluorescent probe solution for latent fingerprint color detection is prepared.

[0090] The dye is the fluorescent probe of this embodiment, and its molecular structure is shown in Formula (1), wherein R1 is R2 is Ar1, Ar2, Ar3 and Ar4 are

[0091] The synthesis steps are as follows:

[0092] Step 1: Add (E)-3-(4-(2-(4-bromophenyl)-1,2-diphenylvinyl)phenyl)propionic acid (1eq), diboronic acid pinacol ester (2eq), potassium acetate (2.5eq) and Pd(dppf)Cl2 (5%) to the reaction bottle in sequence, and then add anhydrous dioxane as the reaction solvent. The temperature slowly rises to 90°C and stirs for 10h. After the reaction, the solvent is removed by vacuum concentration. The crude product is purified by column chromatography to obtain white solid compound 3-1. (Yield 60%).

[0093] Step 2: Add 3-amino-1-propanol and 4-bromo-1,8-naphthalene dicarboxylic anhydride (1 eq) into a reaction flask, then add ethanol as a reaction solvent, and heat under reflux for two hours. After cooling to room temperature, the product precipitates. Filter the product and dry it in a vacuum drying oven to obtain compound 3-2 as a gray solid (yield 80%).

[0094] Step 3: Compound 3-2 (1 eq), compound 3-1 (1.3 eq), K2CO3 (7.5 eq), tetrabutylammonium hydrogen sulfate (10%), and Pd(pph3)4 (20%) were added to the reaction flask in sequence. Then a mixed solution of toluene and water (V / V=2 / 1) was added. Stir at 90°C for 16 hours, the reaction was completed, and the mixture was cooled to room temperature. DCM was used for extraction, the solvent was evaporated under reduced pressure, and the crude product was purified by column chromatography to obtain the reactant 3-3 (yield 60%) as a yellow solid.

[0095] Step 4: Compound 3-3 (1 eq), 1-hydroxypyridine-2,5-dione (2 eq) and DCC (2 eq) were placed in a reaction bottle in sequence. DCM was used as the reaction solvent. The mixture was stirred at room temperature for 12 h, and the reaction was completed. Solid impurities were filtered out. The final product compound was separated and purified by column chromatography to obtain a yellow solid (yield 60%).

[0096] The fluorescent probe is used for fluorescence imaging detection of latent fingerprints with a stainless steel substrate, and the following results can be obtained: Figure 6 ,As can be seen from the figure, the fingerprint imaging is clear and the ,feature recognition of the fingerprint can reach the third level of details.

[0097] Similar to the fluorescent probe molecular structure of this embodiment, for example, R1 is R2 is Ar1 is Ar2, Ar3 and Ar4 are each independently When one of the above is used, the preparation method is similar to the fluorescent probe molecular structure of this embodiment. When the same method is used for fingerprint imaging, a better fingerprint imaging effect can also be achieved.

[0098] Comparative Example 1

[0099] First, the developer of the fluorescent probe of this comparative example was prepared at a concentration of 5×10 -5 M. Mix the fluorescent probe, acetonitrile and water in a glass bottle, and then mix them evenly by ultrasonic until there are no particles visible to the naked eye in the solution. At this point, the fluorescent probe solution for latent fingerprint color detection is prepared.

[0100] The molecular structure of the fluorescent probe of this comparative example is shown in Formula (I), wherein Ar1, Ar2, Ar3 and Ar4 are R1 is (does not contain active ester group), R2 is H.

[0101] It can be synthesized by the following method:

[0102] Step 1: Add 1-(4-bromophenyl)-1,2,2-triphenylethylene (1eq), bipyralidin (2eq), potassium acetate (2.5eq) and Pd(dppf)Cl2 (5%) to the reaction flask in sequence, and then add anhydrous dioxane as the reaction solvent. The temperature is slowly raised to 90°C and stirred for 10 hours. After the reaction, the solvent is removed by vacuum concentration. The crude product is purified by column chromatography to obtain white solid compound 1. (Yield 60%).

[0103] Step 2: Add β-alanine (1 eq) and 4-bromo-1,8-naphthalene dicarboxylic anhydride (1 eq) into a reaction flask, then add ethanol as a reaction solvent, and heat under reflux for two hours. After cooling to room temperature, the product precipitates. Filter the product and dry it in a vacuum drying oven to obtain compound 2 as a gray solid (yield 80%).

[0104] Step 3: Add compound 2 (1 eq), compound 1 (1.3 eq), K2CO3 (7.5 eq), tetrabutylammonium hydrogen sulfate (10%), and Pd(pph3)4 (20%) to the reaction flask in sequence. Then add a mixed solution of toluene and water (V / V=2 / 1). Stir at 90°C for 16 hours, the reaction is completed, and the mixture is cooled to room temperature. Extract with DCM, evaporate the solvent under reduced pressure, and purify the crude product by column chromatography to obtain reactant 3 (yield 60%) as a yellow solid. At this point, the synthesis of latent fingerprint fluorescent probe 3 in Comparative Example 1 is completed.

[0105] The solution of several major chemical substances in fingerprint traces was used to draw a special shape on the surface of the stainless steel substrate using the comparative probe 3. Then the stainless steel substrate sample was stained with the prepared probe solution. It was observed that the comparative probe 3 had no fluorescence response to amino acids and cholesterol, but only had a fluorescence response to lipids, such as Figure 7 shown.

[0106] The fingerprint development capability was tested on stainless steel substrates. Figure 8 As shown, comparative probe 3 can only develop lipid fingerprints, but not glycine fingerprints. However, the probe in Example 1 can perform fluorescence development on both lipid fingerprints and glycine fingerprints.

[0107] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-target responsive aggregation-induced fluorescent probe. It is characterized in that It has the general structural formula shown in formula (1): Formula (I) Among them, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents an aromatic ring structure having 6 to 30 carbon atoms, R 1 and R 2 Each is independently H, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or an alkyl alcohol having 1 to 30 carbon atoms, or one of the following formulas (15) to (20), and R 1 and R 2 At least one of the following formulas (15) to (20): Form (15) Form (16) Form (17) Form (18) Formula (19) Formula (20).

2. A multi-target responsive aggregation-induced fluorescent probe, It is characterized in that It has the general structural formula shown in formula (1): Formula (I) Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each is independently one of the following formulas (II) to (XIV): Formula (2) Formula (3) Formula (4) Formula (5) Type (six) Type (seven) Type (eight) Type (nine) Style (10) Style (11) Style (12) Style (13) Formula (XIV) Among them, R 3 is an alkyl group having 1 to 8 carbon atoms, an amino-terminated alkyl group having 1 to 8 carbon atoms, or a hydroxy-terminated alkyl group having 1 to 8 carbon atoms; R 1 and R 2 Each is independently H, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or an alkyl alcohol having 1 to 30 carbon atoms, or one of the following formulas (15) to (20), and R 1 and R 2 At least one of the following formulas (15) to (20): Form (15) Form (16) Form (17) Form (18) Formula (19) Formula (20).

3. Use of the aggregation-induced fluorescent probe as claimed in claim 1 or 2, It is characterized in that Used for latent fingerprint fluorescence imaging.

4. The use according to claim 3, It is characterized in that A solution containing the aggregation-induced fluorescent probe is brought into contact with a carrier containing a latent fingerprint, so that the aggregation-induced fluorescent probe reacts and combines with a target substance in the fingerprint trace, and finally forms an aggregation state of the probe at the ridge line of the latent fingerprint. Under the excitation of an excitation light source, the excited aggregation-induced fluorescent probe molecules decay back to the ground state through radiation, and emit fluorescence, thereby realizing fluorescent imaging of the latent fingerprint.

5. The use according to claim 4, It is characterized in that The solution containing the aggregation-induced fluorescent probe is dropped onto the carrier containing the latent fingerprint, or the solution containing the aggregation-induced fluorescent probe is sprayed onto the carrier containing the latent fingerprint, or the carrier containing the latent fingerprint is immersed in the solution of the aggregation-induced fluorescent probe, so that the solution of the fluorescent probe contacts the carrier containing the latent fingerprint.

6. The use according to claim 4, It is characterized in that The aggregation-induced fluorescent probe solution is an aqueous solution of the aggregation-induced fluorescent probe, an organic solution of the aggregation-induced fluorescent probe, or a solution obtained by dissolving the aggregation-induced fluorescent probe in a mixed solvent.

7. The use according to claim 4, It is characterized in that The concentration of the fluorescent probe in the aggregation-induced fluorescent probe solution is 0.1 μmol / L to 2 mol / L.

8. The use according to claim 4, It is characterized in that The excitation light source is ultraviolet light or visible light, and its wavelength is 190 nanometers to 520 nanometers.

9. A latent fingerprint developer, It is characterized in that The solution contains the aggregation-induced fluorescent probe as claimed in claim 1 or 2.

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