Fluorescent probe and application thereof
By designing fluorescent probes with aromatic rings and hydrophilic groups to regulate their hydrophilicity and ester-philicity, the problem of poor development clarity of traditional fluorescent probes on different carriers is solved, and high quality on the surfaces of multiple carriers is achieved latent fingerprint imaging and reduce background interference.
Patent Information
- Application Number
- CN202411413174.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-01-10
AI Technical Summary
The traditional latent fingerprint imaging method based on aggregation-induced luminescence has poor development clarity on the surface of different carriers, making it difficult to achieve high-quality latent fingerprint imaging.
A fluorescent probe was designed, with aromatic rings as planar conjugated structures and hydrophilic groups, and the hydrophilicity and ester-philicity of the fluorescent probes were regulated by regulating the length of the alkyl chain and alkoxy chain. Enhance its clarity in latent fingerprint development on various carrier surfaces.
It realizes latent fingerprint imaging with high definition on different carrier surfaces, improves the universality of fluorescent probes and the aggregation-induced luminescence effect, reduces background fluorescence interference, and significantly improves the detection and imaging effect of latent fingerprints.
Smart Images
Figure CN119285536A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fluorescent probes, and in particular to a fluorescent probe and its application. Background Art
[0002] Fingerprints refer to the skin folds with specific structures at the end of human fingers. Fingerprints are composed of inactive stratum corneum cells on the surface of the skin. As long as the dermis tissue is not damaged, fingerprints will not change since the formation of human beings. In human production and life, fingers will naturally come into contact with the face, neck and head. This makes the fingers naturally come into contact with the relevant secretions produced on the surface of the skin. In addition, human fingers themselves will also secrete substances such as sweat. Therefore, the chemical substances on the surface of the fingers include, but are not limited to, lipids, amino acids, peptides, sodium chloride, urea, glucose, cholesterol, lactic acid, lysozyme, etc.
[0003] Latent fingerprint imaging plays an important role in the field of criminal investigation and forensic science. Due to the uniqueness, specificity, and lifelong invariance of fingerprints, the feature recognition of latent fingerprints can accurately identify individuals and often appear as important evidence in criminal investigation and forensic science. Traditional fingerprint imaging methods have some defects, such as low imaging contrast, poor selectivity and sensitivity. Among the many latent fingerprint fluorescence imaging methods, the latent fingerprint imaging method based on aggregation-induced luminescence effectively reduces the interference of background fluorescence and is expected to achieve in-situ real-time detection of latent fingerprints. However, in the latent fingerprint imaging method based on aggregation-induced luminescence, there is a technical problem that the clarity of the latent fingerprint development of the fluorescent probe on different carrier surfaces is poor. Summary of the invention
[0004] The present application provides a fluorescent probe and its application to solve the following technical problem: how to improve the clarity of latent fingerprint development when the fluorescent probe is applied to various carrier surfaces.
[0005] In a first aspect, the present application provides a fluorescent probe having a general structural formula as shown in formula (1):
[0006]
[0007] In formula (1), Ar1 is an aromatic ring, R1 is a substituent at any position in Ar1, and R1 includes one of the following: a straight-chain saturated alkyl chain, a straight-chain saturated alkoxy chain; Ar2 is an aromatic ring, R1 is a substituent at any position in R2, and R2 is a hydrophilic group.
[0008] Optionally, the number of carbon atoms n in R1 is 1-14.
[0009] Optionally, the R2 includes one of the following:
[0010]
[0011] Optionally, the aromatic ring includes one of the following:
[0012]
[0013] In a second aspect, the present application provides an application of the fluorescent probe described in any embodiment of the first aspect in fingerprint fluorescence imaging.
[0014] Optionally, the application includes the following steps:
[0015] contacting a solution containing a fluorescent probe with a carrier containing a latent fingerprint, so that the fluorescent probe is aggregated at the ridges of the latent fingerprint;
[0016] The fluorescent probes gathered at the ridges of the latent fingerprint emit fluorescence under the excitation of ultraviolet light to achieve fluorescent imaging of the latent fingerprint.
[0017] Optionally, the method of contacting the solution containing the fluorescent probe with the carrier containing the latent fingerprint includes:
[0018] Dropping a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or,
[0019] Spraying a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or,
[0020] The carrier containing the latent fingerprint is immersed in a solution of the fluorescent probe.
[0021] Optionally, the concentration of the fluorescent probe in the fluorescent probe solution is 5×10 -5 mol / L~10 -4 mol / L; and / or,
[0022] The solvent in the solution of the fluorescent probe includes at least one of the following: deionized water, ethanol, methanol, and acetonitrile.
[0023] Optionally, the wavelength of the ultraviolet light is 300 nanometers to 420 nanometers.
[0024] Optionally, the carrier includes one of the following: glass, tin foil, plastic, and stainless steel plate.
[0025] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:
[0026] The fluorescent probe provided in the embodiment of the present application has a general structural formula in which Ar1 and Ar2 are aromatic rings, which can serve as a basic planar conjugated structure and serve as relatively independent rotor structures at both ends of the double bond, thereby enhancing the aggregation-induced emission effect of the fluorescent probe; R2 can regulate the water solubility of the fluorescent probe; R1 includes one of the following: a straight-chain saturated alkyl chain and a straight-chain saturated alkoxy chain, and the straight-chain saturated alkyl chain and the alkoxy chain can finely and accurately regulate their lipid-water partition coefficients as their chains are extended, i.e., the number of carbon atoms gradually increases, which means that the hydrophilicity and lipophilicity of the fluorescent probe can be finely and accurately regulated by increasing or shortening the length of the alkyl chain, so that the hydrophilicity and lipophilicity of the fluorescent probe can be finely and accurately regulated by using straight-chain saturated alkyl chains or alkoxy chains of different lengths to adapt to high-quality latent fingerprint development of substrates of different materials, thereby obtaining high-definition imaging images, so the fluorescent probe has good universality. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0029] Figure 1 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 1 of the present application on a glass material background;
[0030] Figure 2 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 1 of the present application on a tinfoil material background;
[0031] Figure 3 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 1 of the present application on a plastic material background;
[0032] Figure 4 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 2 of the present application on a plastic material background;
[0033] Figure 5 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 2 of the present application on a stainless steel material background;
[0034] Figure 6This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 3 of the present application on a tinfoil material background;
[0035] Figure 7 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 3 of the present application on a plastic material background. DETAILED DESCRIPTION
[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0037] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.
[0038] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of the present application, the terms "include", "comprise", etc. refer to "including but not limited to". In this article, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.
[0039] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.
[0040] In a first aspect, the present application provides a fluorescent probe having a general structural formula as shown in formula (1):
[0041]
[0042] In formula (1), Ar1 is an aromatic ring, R1 is a substituent at any position in Ar1, and R1 includes one of the following: a straight-chain saturated alkyl chain, a straight-chain saturated alkoxy chain; Ar2 is an aromatic ring, R1 is a substituent at any position in R2, and R2 is a hydrophilic group.
[0043] In the embodiment of the present application, in the general structural formula of the fluorescent probe, Ar1 and Ar2 are aromatic rings, which can serve as a basic planar conjugated structure as a relatively independent rotor structure at both ends of the double bond, thereby enhancing the aggregation-induced emission effect of the fluorescent probe; R2 can regulate the water solubility of the fluorescent probe; R1 may include one of the following: a straight-chain saturated alkyl chain, a straight-chain saturated alkoxy chain, and the straight-chain saturated alkyl chain and the alkoxy chain can finely and accurately regulate their lipid-water partition coefficients as their chains are extended, that is, the number of carbon atoms gradually increases, which means that the hydrophilicity and lipophilicity of the fluorescent probe can be finely and accurately regulated by increasing or shortening the length of the alkyl chain, so that by using straight-chain saturated alkyl chains or alkoxy chains of different lengths, the hydrophilicity and lipophilicity of the fluorescent probe can be finely and accurately regulated to adapt to high-quality latent fingerprint development of substrates of different materials, thereby obtaining high-definition imaging images, so the fluorescent probe method has good universality.
[0044] In some embodiments, the number of carbon atoms n in R1 is 1-14.
[0045] In the embodiment of the present application, the number of carbon atoms n in R1 can be 1 to 14. The lipid-water partition coefficient of the fluorescent probe can be finely and accurately regulated by adjusting the number of carbon atoms in the linear saturated alkyl chain or alkoxy chain in the fluorescent probe, so that the fluorescent probe can be used for latent fingerprint development on the surface of a substrate of a variety of different materials. The appropriate number of carbon atoms in R1 can ensure the hydrophilicity of R1. For example, the number of carbon atoms n in the above R1 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, etc.
[0046] In some embodiments, the R2 comprises one of the following:
[0047]
[0048] In the embodiment of the present application, R2 is a hydrophilic group, which can regulate the water solubility of the fluorescent probe, wherein R2 has a protonated structure, which effectively enhances the push-pull electron effect in the fluorescent probe, and is very beneficial to the enhancement of the fluorescence emission of the fluorescent probe. On the other hand, the protonated structure is also beneficial to the regulation of the hydrophilicity of the fluorescent probe.
[0049] In some embodiments, the aromatic ring comprises one of the following:
[0050]
[0051] In the embodiment of the present application, Ar1 and Ar2 are aromatic rings, and the basic planar conjugated structure acts as a relatively independent rotor structure at both ends of the double bond to enhance the aggregation-induced luminescence effect of the fluorescent probe. The aggregation-induced luminescence effect not only represents its stable and high-quality fluorescence emission in the aggregated state during the latent fingerprint imaging process. On the other hand, the enhanced fluorescence emission in the aggregated state and the weak fluorescence in the dispersed state are more conducive to effectively reducing the background fluorescence in the latent fingerprint imaging process. In addition, Ar1 and Ar2 are both simple basic planar structures, and the introduced synthesis steps are relatively simple, which is conducive to mass synthesis and cost reduction.
[0052] The fluorescent probe provided in the embodiments of the present application can be prepared by conventional preparation methods, and multiple fluorescent probes of the same type can be prepared in batches by preparing intermediates.
[0053] In a second aspect, the present application provides an application of the fluorescent probe described in any embodiment of the first aspect in fingerprint fluorescence imaging.
[0054] In some embodiments, the application comprises the following steps:
[0055] contacting a solution containing a fluorescent probe with a carrier containing a latent fingerprint, so that the fluorescent probe is aggregated at the ridges of the latent fingerprint;
[0056] The fluorescent probes gathered at the ridges of the latent fingerprint emit fluorescence under the excitation of ultraviolet light to achieve fluorescent imaging of the latent fingerprint.
[0057] In the embodiments of the present application, the linear fluorescent probe solution modified with the straight-chain saturated alkyl chain or the straight-chain saturated alkoxy chain is brought into contact with the latent fingerprint trace, so that the fluorescent probe is targetedly adsorbed at the ridge line of the latent fingerprint trace to form an aggregation; under the excitation of ultraviolet light, fluorescence is emitted based on the principle of aggregation-induced luminescence, thereby realizing the detection and imaging of the latent fingerprint trace.
[0058] In some embodiments, the method of contacting a solution containing a fluorescent probe with a carrier containing a latent fingerprint comprises:
[0059] Dropping a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or,
[0060] Spraying a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or,
[0061] The carrier containing the latent fingerprint is immersed in a solution of the fluorescent probe.
[0062] In the implementation of the present application, the solution containing the fluorescent probe is contacted with the carrier containing the latent fingerprint. The solution containing the fluorescent probe can be dripped onto the carrier containing the latent fingerprint, or the solution containing the fluorescent probe is sprayed onto the carrier containing the latent fingerprint by ultrasonic atomization spraying, or the carrier containing the latent fingerprint is immersed in the solution of the fluorescent probe. In addition, after the fluorescent probe solution contacts the latent fingerprint trace, the fluorescent probe gathers at the ridge of the latent fingerprint trace, and the excess solution needs to be removed. After the fluorescent probe gathers at the ridge of the latent fingerprint, the excess fluorescent probe solution is removed. Exemplarily, the residual solution can be blown away by using an inclined substrate, or by using an ear bulb, or by using nitrogen to blow away the excess solution.
[0063] In addition, by using the solution containing fluorescent probes provided in the embodiments of the present application and with the aid of a photographing device, latent fingerprints on the surface of a smooth object can be immersed in a solution of fluorescent probes and then revealed by ultraviolet light excitation, thereby more easily and directly obtaining fluorescent fingerprint imaging with low background noise, high brightness, and high definition.
[0064] In some embodiments, the concentration of the fluorescent probe in the fluorescent probe solution (developer) is 5×10 - 5 mol / L~10 -4 mol / L; and / or,
[0065] The solvent in the solution of the fluorescent probe includes at least one of the following: deionized water, ethanol, methanol, and acetonitrile.
[0066] In the embodiment of the present application, the concentration of the fluorescent probe in the fluorescent probe aqueous solution can be 10 -4 mol / L~5×10 -5 mol / L, which can effectively exert its aggregation-induced luminescence effect. And while ensuring the fluorescence development of latent fingerprints, the background fluorescence is minimized. The lower concentration of the fluorescent probe in the developer is also conducive to saving molecules and saving costs. For example, the concentration of the fluorescent probe can be 10 -4 mol / L、2×10 -5 mol / L、3×10 -5 mol / L、4×10 -5 mol / L、5×10 -5mol / L, etc. In addition, the solvent in the solution of the fluorescent probe can be one or more combinations of deionized water, ethanol, methanol, and acetonitrile.
[0067] In some embodiments, the wavelength of the ultraviolet light is 300 nanometers to 450 nanometers.
[0068] In the embodiments of the present application, it should be noted that the wavelength of the ultraviolet light may be 300 nanometers to 450 nanometers. For example, the wavelength of the ultraviolet light may be 300 nanometers, 320 nanometers, 350 nanometers, 380 nanometers, 400 nanometers, 420 nanometers, etc.
[0069] In some embodiments, the carrier comprises one of the following: glass, tin foil, plastic, and stainless steel plate.
[0070] In the embodiment of the present application, the carrier can be one of glass, tin foil, plastic, and stainless steel plate.
[0071] The application of the fluorescent probe in fingerprint fluorescence imaging is realized based on the above-mentioned fluorescent probe. The specific molecular structure of the fluorescent probe can refer to the above-mentioned embodiment. Since the application of the fluorescent probe in fingerprint fluorescence imaging adopts part or all of the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.
[0072] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.
[0073] Example 1
[0074] The molecular structure of a fluorescent probe is shown in formula (1):
[0075]
[0076] In formula (1), Ar1 is R1 is Ar2 is R2 is
[0077]
[0078] A method for preparing a fluorescent probe comprises: adding 4-octyloxybenzaldehyde (1.00 eq) and 1-(2-hydroxyethyl)-4-methylpyridin-1-ium (1.05 eq) into a reaction bottle, adding an appropriate amount of acetonitrile as a reaction solvent, adding a catalytic amount of piperidine, heating to 8° C., heating and stirring for reaction for 12 hours, and obtaining a fluorescent probe.
[0079] Application of the fluorescent probe prepared in Example 1
[0080] (1) First, according to 10 -4 A quantitative fluorescent probe solid (Example 1) with a concentration of 1 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present, to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0081] The method uses the solution containing the fluorescent probe to perform fluorescence detection imaging of latent fingerprints on the surface of a glass substrate, including: after leaving a latent fingerprint trace on the surface of the glass substrate, using the solution containing the fluorescent probe to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: dripping the solution containing the fluorescent probe (latent fingerprint developer) onto the surface of the glass substrate, blowing away the excess solution with nitrogen after 20 seconds, emitting yellow-green fluorescence under 365nm light excitation, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0082] (2) First, according to 10 -4 A quantitative fluorescent probe solid (Example 1) with a concentration of 1 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present, to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0083] The method uses the solution containing the fluorescent probe to perform fluorescence detection imaging of latent fingerprints on the surface of a tinfoil substrate, including: after leaving a latent fingerprint trace on the surface of the tinfoil substrate, the solution containing the fluorescent probe is used to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: dripping the solution containing the fluorescent probe (latent fingerprint developer) onto the surface of the tinfoil substrate, blowing away the excess solution with nitrogen after 20 seconds, emitting green fluorescence under 365nm light excitation, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0084] (3) First, according to 10 -4 A quantitative fluorescent probe solid (Example 1) with a concentration of 1 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present, to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0085] The method uses the solution containing the fluorescent probe to perform fluorescence detection and imaging of latent fingerprints on the surface of the plastic glove substrate, including: after leaving a latent fingerprint trace on the surface of the plastic glove substrate, using the solution containing the fluorescent probe to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: using the solution containing the fluorescent probe (latent fingerprint developer) to drop onto the surface of the plastic glove substrate, blowing away the excess solution with nitrogen after 20 seconds, emitting green fluorescence under 365nm light excitation, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0086] Example 2
[0087] The molecular structure of a fluorescent probe is shown in formula (1):
[0088]
[0089] In formula (1), Ar1 is R1 is Ar2 is R2 is
[0090] A method for preparing a fluorescent probe comprises: adding 4-butoxybenzaldehyde (1.00 eq) and 1-(2-hydroxyethyl)-4-methylpyridin-1-ium (1.05 eq) into a reaction bottle, adding an appropriate amount of acetonitrile as a reaction solvent, adding a catalytic amount of piperidine, heating to 8° C., heating and stirring for reaction for 12 hours, and obtaining a fluorescent probe.
[0091] Example 2 Application of the fluorescent probe prepared
[0092] (1) First, according to 10 -4 A quantitative fluorescent probe solid (Example 2) with a concentration of 1.5 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present, to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0093] The method uses the solution containing the fluorescent probe to perform fluorescence detection imaging of latent fingerprints on the surface of a plastic substrate, including: after leaving a latent fingerprint trace on the surface of a glass substrate, using the solution containing the fluorescent probe to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: using the solution containing the fluorescent probe (latent fingerprint developer) to drop onto the surface of the glass substrate, blowing away the excess solution with nitrogen after 20 seconds, emitting yellow-green fluorescence under the excitation of 365nm light, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0094] (2) First, according to 10 -4A quantitative fluorescent probe solid (Example 2) with a concentration of 1.5 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present, to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0095] The method uses the solution containing the fluorescent probe to perform latent fingerprint fluorescence detection imaging on the surface of the stainless steel substrate, including: after leaving a latent fingerprint trace on the surface of the glass substrate, the solution containing the fluorescent probe is used to perform latent fingerprint fluorescence imaging. Specifically, the method includes the following steps: dripping the solution containing the fluorescent probe (latent fingerprint developer) onto the surface of the glass substrate, blowing away the excess solution with nitrogen after 20 seconds, and then emitting yellow-green fluorescence under 365nm light excitation, and taking a fluorescent latent fingerprint photo with a SLR camera.
[0096] Example 3
[0097] The molecular structure of a fluorescent probe is shown in formula (1):
[0098]
[0099] In formula (1), Ar1 is R1 is Ar2 is R2 is
[0100] A method for preparing a fluorescent probe comprises: adding 4-octylbenzaldehyde (1.00 eq) and 1-(2-hydroxyethyl)-4-methylpyridin-1-ium (1.05 eq) into a reaction bottle, adding an appropriate amount of acetonitrile as a reaction solvent, adding a catalytic amount of piperidine, heating to 8° C., heating and stirring for reaction for 12 hours, and obtaining a fluorescent probe.
[0101] Example 3 Application of the fluorescent probe prepared
[0102] (1) First, according to 10 -4 A quantitative fluorescent probe solid (Example 3) with a concentration of 1.5 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0103] The method uses the solution containing the fluorescent probe to perform fluorescence detection imaging of latent fingerprints on the surface of a tinfoil substrate, including: after leaving a latent fingerprint trace on the surface of a glass substrate, the solution containing the fluorescent probe is used to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: dripping the solution containing the fluorescent probe (latent fingerprint developer) onto the surface of the glass substrate, blowing away the excess solution with nitrogen after 20 seconds, and then emitting yellow-green fluorescence under 365nm light excitation, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0104] (2) First, according to 10 -4 A quantitative fluorescent probe solid (Example 3) with a concentration of 1.5 mol / L was weighed, the solid was mixed with a certain amount of deionized water in a glass bottle, and ultrasonically homogenized until no obvious particles were present to obtain a solution containing the fluorescent probe (latent fingerprint developer solution).
[0105] The method uses the solution containing the fluorescent probe to perform fluorescence detection imaging of latent fingerprints on the surface of a plastic plate substrate, including: after leaving a latent fingerprint trace on the surface of a glass substrate, using the solution containing the fluorescent probe to perform fluorescence imaging of the latent fingerprint. Specifically, the method includes the following steps: dripping the solution containing the fluorescent probe (latent fingerprint developer) onto the surface of the glass substrate, blowing away the excess solution with nitrogen after 20 seconds, emitting yellow-green fluorescence under the excitation of 365nm light, and taking a photo of the fluorescent latent fingerprint using a SLR camera.
[0106] Result analysis:
[0107] Figure 1 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 1 of the present application on a glass material background; see Figure 1 , indicating that on the surface of the glass substrate, clear latent fingerprint traces can be seen under 365nm light excitation, among which the first-level detail features of the latent fingerprint, the spiral traces, are clearly visible, and the second-level detail features of the latent fingerprint, including the intersection, bifurcation, and line endpoints, are basically recognizable; Figure 2 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 1 of the present application on a tinfoil material background; see Figure 2 , indicating that the fluorescence emission intensity of latent fingerprint fluorescence imaging on the tinfoil surface is significantly higher, and latent fingerprint traces are easier to identify; Figure 3 This is a latent fingerprint staining image of a fluorescent probe provided in Example 1 of the present application on a plastic material background; see Figure 3 , indicating that the latent fingerprint on the surface of the plastic glove lining emits strong fluorescence under the immersion of the fluorescent probe solution, and the latent fingerprint imaging has a high imaging contrast. The characteristic points of the latent fingerprint are also more clearly visible. Therefore, the fluorescent probe provided in the embodiment of the present application has a strong ability to detect and develop latent fingerprint traces on the surface of plastic products.
[0108] Figure 4 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 2 of the present application on a plastic material background;
[0109] Figure 5 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 2 of the present application on a stainless steel background; see Figures 4-5By shortening the alkyl chain of the fluorescent probe, the hydrophilicity and hydrophobicity of the probe molecule are changed, which reduces its hydrophobicity and enhances its hydrophilicity. The enhanced hydrophilicity makes it more suitable for latent fingerprint fluorescence imaging on the surface of a material base with better hydrophilicity. The hydrophilicity of untreated stainless steel plates is similar to that of tin foil, while the hydrophilicity of stainless steel plates and tin foil is better than that of untreated plastic plates. Therefore, by shortening the alkyl chain, the hydrophilicity of the probe molecule is better, making it more suitable for clearer latent fingerprint fluorescence imaging on the surface of a hydrophilic substrate (such as a stainless steel plate and tin foil surface).
[0110] Figure 6 This is a latent fingerprint staining imaging image of a fluorescent probe provided in Example 3 of the present application on a tinfoil material background; Figure 7 This is a latent fingerprint staining image of a fluorescent probe on a plastic material background provided in Example 3 of the present application; see Figures 6-7 The alkoxy group has better hydrophilicity than the alkyl chain. Therefore, the hydrophobicity of the probe molecule increases sharply after the alkoxy group is removed and a pure alkyl chain is added. This is more conducive to clear latent fingerprint fluorescence imaging on the surface of a plastic plate substrate with better hydrophobicity.
[0111] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:
[0112] (1) The linear aggregation-induced fluorescent probe modified with a straight-chain saturated alkyl chain or a straight-chain saturated alkoxy chain provided in the embodiments of the present application is used in fingerprint fluorescence imaging. Since the linear aggregation-induced fluorescent probe has excellent aggregation-induced luminescence properties, the fluorescent probe does not emit fluorescence in a dispersed state in a solution, and only emits fluorescence when it contacts the surface of a latent fingerprint trace and forms an aggregation state at the fingerprint ridge line, thereby effectively reducing the interference of background fluorescence;
[0113] (2) The fluorescent probes of the same type provided in the embodiments of the present application have similar and simple structures and can be synthesized through simple steps under mild conditions and are not dangerous. Similar structures enable the batch synthesis of multiple fluorescent probes of the same type through simple intermediate synthesis;
[0114] (3) Due to the specificity of its structure, the fluorescent probe provided in the embodiments of the present application has hydrophilic groups modified at both ends of its molecular core structure, and the molecular core structure is a lipophilic group. Therefore, the hydrophilic and hydrophobic properties of the fluorescent probe can be adjusted over a wide range by replacing the modified groups, lengthening the alkyl chain or the alkoxy chain, etc., making its application scenarios more extensive.
[0115] (4) The fluorescent probe modified with a linear saturated alkyl chain or a linear saturated alkoxy chain provided in the embodiments of the present application has a good aggregation-induced emission property because of the obvious rotor structure at both ends of its double bonds.
[0116] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A fluorescent probe, characterized in that The fluorescent probe has a general structural formula as shown in formula (1): In formula (1), Ar1 is an aromatic ring, R1 is a substituent at any position in Ar1, and R1 includes one of the following: a straight-chain saturated alkyl chain, a straight-chain saturated alkoxy chain; Ar2 is an aromatic ring, R1 is a substituent at any position in R2, and R2 is a hydrophilic group.
2. The fluorescent probe according to claim 1, characterized in that The number of carbon atoms n in R1 is 1-14.
3. The fluorescent probe according to claim 1, characterized in that The R2 includes the following:
4. The fluorescent probe according to claim 1, characterized in that The aromatic ring includes one of the following:
5. Use of the fluorescent probe according to any one of claims 1 to 5 in fingerprint fluorescence imaging.
6. The use according to claim 6, characterized in that: The application comprises the following steps: contacting a solution containing a fluorescent probe with a carrier containing a latent fingerprint, so that the fluorescent probe is aggregated at the ridges of the latent fingerprint; The fluorescent probes gathered at the ridges of the latent fingerprint emit fluorescence under the excitation of ultraviolet light to achieve fluorescent imaging of the latent fingerprint.
7. The use according to claim 6, characterized in that: The method of contacting the solution containing the fluorescent probe with the carrier containing the latent fingerprint includes: Dropping a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or, Spraying a solution containing a fluorescent probe onto a carrier containing a latent fingerprint; or, The carrier containing the latent fingerprint is immersed in a solution of the fluorescent probe.
8. The use according to claim 6, characterized in that: The concentration of the fluorescent probe in the fluorescent probe solution is 5×10 -5 mol / L~10 -4 mol / L; and / or, The solvent in the solution of the fluorescent probe includes at least one of the following: deionized water, ethanol, methanol, and acetonitrile.
9. The use according to claim 6, characterized in that: The wavelength of the ultraviolet light is 300 nanometers to 420 nanometers.
10. The use according to claim 6, characterized in that: The carrier includes one of the following: glass, tin foil, plastic, and stainless steel plate.