Water-soluble fluorescent probe and application thereof
By designing a water-soluble fluorescent probe and utilizing a combination of cyano, aromatic, and hydrophilic groups, the problem of low clarity and recognition of existing fluorescent probes in fingerprint imaging was solved, achieving efficient and rapid imaging of latent fingerprints.
Patent Information
- Application Number
- CN202411413335.6
- 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
Existing fluorescent probes have low clarity and recognition in fingerprint imaging.
A water-soluble fluorescent probe was designed by incorporating cyano groups into its molecular structure to adjust the emission wavelength and brightness, using aromatic ring groups as the core of the fluorescent chromophore, hydrophilic groups to improve water solubility, and alkyl-substituted tertiary amine groups to enhance affinity for latent fingerprint fatty components.
This improves the clarity and recognition of fluorescent probes in fingerprint imaging, enabling rapid, real-time development and high-sensitivity detection of latent fingerprints.
Smart Images
Figure CN119285537A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fluorescent probes, and in particular to a water-soluble fluorescent probe and its application. Background Art
[0002] Fingerprints refer to skin lines with special shapes composed of ridges (convex fingerprint lines) and small furrows (concave fingerprint lines) that appear at the ends of human fingers. They are highly recognizable to their holders, that is, unique and lifelong. Therefore, in forensic science, the holder can be quickly and accurately identified by analyzing and comparing the detailed features of fingerprint traces at the crime scene. Latent fingerprints are the fingerprints that appear most frequently at crime scenes. They refer to fingerprint traces caused by chemical residues on the surface of the finger when the finger touches the surface of an ordinary object. In most cases, the existence of latent fingerprints is relatively hidden and cannot be directly observed by the human eye. Therefore, based on the relatively stable chemical components on the surface of latent fingerprint traces, it is particularly important to develop a method to make latent fingerprints emit fluorescence to obtain latent fingerprint imaging.
[0003] However, existing fluorescent probes have the problem of clarity and low recognition in fingerprint imaging. Summary of the invention
[0004] The present application provides a water-soluble fluorescent probe and its application to solve the following technical problem: how to improve the clarity and recognition of the fluorescent probe in fingerprint imaging.
[0005] In a first aspect, the present application provides a water-soluble 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 of Ar1, and R1 is an alkyl-substituted tertiary amine group; Ar2 is an aromatic ring; R2 is a substituent at any position of Ar2; and R2 is a hydrophilic group.
[0008] Optionally, R1 is one of the following: a cyclic alkyl substituted tertiary amine group, a linear alkyl substituted tertiary amine group.
[0009] Optionally, the cyclic alkyl-substituted tertiary amine group is one of the following:
[0010]
[0011] Optionally, the linear alkyl-substituted tertiary amine group is one of the following: dodecyldimethyl tertiary amine and octadecyldimethyl tertiary amine.
[0012] Optionally, Ar1 is one of the following: a benzene ring, a naphthalene ring, or thiophene.
[0013] Optionally, Ar2 is one of the following: a benzene ring, a naphthalene ring, pyridine, an onium salt of pyridine, or an onium salt of quinoline.
[0014] Optionally, the R2 is one of the following:
[0015]
[0016] Ionic groups, hydroxyethyl, polyethylene glycol.
[0017] In a second aspect, the present application provides an application of the water-soluble fluorescent probe described in any one of the first aspects in latent fingerprint imaging.
[0018] Optionally, the application includes the following steps:
[0019] 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;
[0020] 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.
[0021] Optionally, the contacting method includes one of the following: a spraying method and a chemical dipping method.
[0022] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:
[0023] The water-soluble fluorescent probe provided in the embodiment of the present application has a cyano group connected to one end of the double bond in the molecular structure of the fluorescent probe, and the cyano group can adjust the emission wavelength and brightness of the fluorescent probe; the aromatic ring groups Ar1 and Ar2 connected to the two ends of the double bond can serve as the core of the fluorescent chromophore to determine the emission wavelength and ensure the aggregation-induced emission effect of the probe molecule; the hydrophilic group R2 can enhance the water solubility of the fluorescent probe, so that it can be dissolved in a solvent with a higher polarity; R1 is an alkyl-substituted tertiary amine group, and the alkyl-substituted tertiary amine group can improve the affinity of the fluorescent probe to the fat component of the latent fingerprint, and the hydrophilic group R2 can give the fluorescent probe a water-soluble characteristic and reduce nonspecific adsorption. Therefore, the fluorescent probe has both strong lipophilicity and water solubility, thereby improving the clarity and recognition of the fluorescent probe in fingerprint imaging. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] 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.
[0025] 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.
[0026] Figure 1 A UV-visible absorption spectrum of a water-soluble fluorescent probe provided in Examples 1 and 2 of the present application; wherein 1-Example 1, 2-Example 2;
[0027] Figure 2 A fluorescence emission spectrum of a water-soluble fluorescent probe provided in Examples 1 and 2 of the present application; wherein 1-Example 1, 2-Example 2;
[0028] Figure 3 A water-soluble fluorescent probe provided in Example 1 of the present application is used to image a fluorescent image of a latent fingerprint using a chemical immersion method;
[0029] Figure 4 A water-soluble fluorescent probe provided in Example 1 of the present application uses a spray method to image a fluorescent image of a latent fingerprint. DETAILED DESCRIPTION
[0030] 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.
[0031] 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.
[0032] 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.
[0033] In a first aspect, the present application provides a water-soluble fluorescent probe having a general structural formula as shown in formula (1):
[0034]
[0035] In formula (1), Ar1 is an aromatic ring; R1 is a substituent at any position of Ar1, and R1 is an alkyl-substituted tertiary amine group; Ar2 is an aromatic ring; R2 is a substituent at any position of Ar2; and R2 is a hydrophilic group.
[0036] In the embodiment of the present application, in the molecular structure of the fluorescent probe, a cyano group is connected to one end of the double bond, and the cyano group can adjust the emission wavelength and brightness of the fluorescent probe; the aromatic ring groups Ar1 and Ar2 connected to the two ends of the double bond can serve as the core of the fluorescent chromophore to determine the emission wavelength and ensure the aggregation-induced emission effect of the probe molecule; the hydrophilic group R2 can enhance the water solubility of the fluorescent probe, so that it can be dissolved in a solvent with a higher polarity; R1 is an alkyl-substituted tertiary amine group, which can improve the affinity of the fluorescent probe to the fat component of the latent fingerprint, and the hydrophilic group R2 can give the fluorescent probe water-soluble characteristics and reduce nonspecific adsorption. Therefore, the fluorescent probe has both strong lipophilicity and water solubility, thereby improving the clarity and recognition of the fluorescent probe in fingerprint imaging.
[0037] In some embodiments, the R1 is one of the following: a cyclic alkyl substituted tertiary amine group, a linear alkyl substituted tertiary amine group.
[0038] In some embodiments, the cyclic alkyl-substituted tertiary amine group is one of the following:
[0039]
[0040] In some embodiments, the linear alkyl-substituted tertiary amine group is one of the following: dodecyldimethyl tertiary amine, octadecyldimethyl tertiary amine.
[0041] In the embodiment of the present application, the affinity of the fluorescent probe to latent fingerprints is improved by alkyl-substituted tertiary amine groups, especially the affinity of the probe to the fat component of latent fingerprints. The alkyl-substituted tertiary amine groups have certain interactions with components such as grease and sweat in fingerprints. And the hydrophilicity of the alkyl-substituted tertiary amine groups can be balanced by adjusting the length of the alkyl chain of the alkyl-substituted tertiary amine groups. The alkyl-substituted tertiary amine groups can be one of cyclic alkyl-substituted tertiary amine groups or linear alkyl-substituted tertiary amine groups.
[0042] In some embodiments, Ar1 is one of the following: a benzene ring, a naphthalene ring, or a thiophene ring.
[0043] In some embodiments, Ar2 is one of the following: a benzene ring, a naphthalene ring, pyridine, an onium salt of pyridine, or an onium salt of quinoline.
[0044] In the embodiment of the present application, Ar1 and Ar2 can serve as the core of the fluorescent chromophore to determine the emission wavelength. Ar1 can be one of a benzene ring, a naphthalene ring, and a thiophene ring, and Ar2 can be one of a benzene ring, a naphthalene ring, pyridine, an onium salt of pyridine, and an onium salt of quinoline.
[0045] In some embodiments, the R2 is one of the following:
[0046]
[0047] Ionic groups, hydroxyethyl, polyethylene glycol.
[0048] In the embodiment of the present application, R2 is a hydrophilic group, which can effectively improve the water solubility of the fluorescent probe.
[0049] In a second aspect, the present application provides an application of the water-soluble fluorescent probe described in any one of the first aspects in latent fingerprint imaging.
[0050] In some embodiments, the application comprises the following steps:
[0051] 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;
[0052] 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.
[0053] In some embodiments, the contacting method comprises one of the following: a spraying method and a chemical dipping method.
[0054] In the embodiment of the present application, the water-soluble fluorescent probe can be used for latent fingerprint imaging, especially for sweat latent fingerprint lipid substances. The fluorescent probe solution is used to contact the latent fingerprint trace, so that the fluorescent probe is targeted and adsorbed at the ridge 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 to achieve the detection and imaging of latent fingerprint traces. The electron donor part and the acceptor part of the fluorescent probe are bridged by a carbon-carbon double bond. In the solution state, the electron donor part and the acceptor part rotate freely around the carbon-carbon double bond, non-radiative attenuation occurs, and the fluorescence is extremely weak. The alkyl-substituted tertiary amine group of the fluorescent probe can be hydrophobically bonded to fatty substances, so that the non-radiative attenuation channel of the fluorescent probe is suppressed due to the restricted intramolecular motion, and the excited state fluorescent probe molecule can only return to the ground state through radiation decay, thereby emitting strong fluorescence. Among them, the above-mentioned contact method can be one of the spray method and the chemical impregnation method.
[0055] The application of the water-soluble fluorescent probe in latent fingerprint imaging is realized based on the above-mentioned water-soluble fluorescent probe. The specific molecular structure of the water-soluble fluorescent probe can refer to the above-mentioned embodiment. Since the application of the water-soluble fluorescent probe in latent fingerprint imaging adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.
[0056] 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.
[0057] Example 1
[0058] A fluorescent probe molecule, whose molecular structure is shown in formula (1):
[0059]
[0060] In formula (1), Ar1 is phenyl; R1 is Ar2 is pyridine; R2 is hydroxyethyl.
[0061] A method for preparing a fluorescent probe molecule comprises: adding 4-(piperidinyl)benzaldehyde (1 mmol) and 4-(isocyanomethyl)-N-(2-hydroxyethyl)-pyridine (1 mmol) into a reaction bottle, then adding 40 mL of ethanol as a reaction solvent, placing a magnetic bar, dripping 2 drops of piperidine, heating to 80°C, uniformly stirring and heating to react for about 24 hours, cooling to room temperature after the reaction is completed, concentrating the solvent under reduced pressure, and purifying the residue by silica gel (eluent: dichloromethane: methanol=20:1) preparative column chromatography to obtain an orange-yellow solid fluorescent probe 1, with a yield of 65%.
[0062] UV test
[0063] Using water as solvent, the fluorescent probe 1 was prepared at a concentration of 1×10 -5 M sample solution, and then use a Shimatsu UV-Vis spectrophotometer with a 1 cm quartz cuvette to first perform a baseline scan on the blank water (scanning range: 300-800 nm). After deducting the background, scan the sample solution and measure its UV-Vis absorption spectrum.
[0064] Fluorescence test
[0065] Using water as solvent, the fluorescent probe 1 was prepared at a concentration of 1×10 -5 M sample solution, 0.2 mL of the sample solution was injected into 1.8 mL of THF, and then the sample solution was tested using an Edinburgh 9800 fluorescence spectrophotometer with a 1 cm quartz cuvette at an excitation wavelength of 365 nm to measure its fluorescence emission spectrum.
[0066] Example 2
[0067] A fluorescent probe molecule, whose molecular structure is shown in formula (1):
[0068]
[0069] In formula (1), Ar1 is phenyl; R1 is Ar2 is pyridine; R2 is hydroxyethyl. A method for preparing a fluorescent probe molecule comprises: adding 4-(N-methylpiperazinyl)benzaldehyde (1mmol), 4-(isocyanomethyl)-N-(2-hydroxyethyl)-(1mmol) into a reaction bottle, and then adding 40mL of ethanol as a reaction solvent, placing a magnetic bar, dropping 2 drops of piperidine, heating to 80°C, stirring and heating uniformly for about 24 hours, cooling to room temperature after the reaction is completed, concentrating the solvent under reduced pressure, and purifying the residue by silica gel (eluent: dichloromethane: methanol = 20:1) preparative column chromatography to obtain an orange-yellow solid fluorescent probe 2, with a yield of 62%.
[0070] UV test
[0071] Using water as solvent, the fluorescent probe 1 was prepared at a concentration of 1×10 -5 M sample solution, and then use a Shimatsu UV-Vis spectrophotometer with a 1 cm quartz cuvette to first perform a baseline scan on the blank water (scanning range: 300-800 nm). After deducting the background, scan the sample solution and measure its UV-Vis absorption spectrum.
[0072] Fluorescence test
[0073] Using water as solvent, the fluorescent probe 1 was prepared at a concentration of 1×10 -5 M sample solution, 0.2 mL of the sample solution was injected into 1.8 mL of THF, and then the sample solution was tested using an Edinburgh 9800 fluorescence spectrophotometer with a 1 cm quartz cuvette at an excitation wavelength of 365 nm to measure its fluorescence emission spectrum.
[0074] Figure 1 This is a UV-visible absorption spectrum of a water-soluble fluorescent probe provided in Example 1 and Example 2 of the present application; wherein 1-Example 1, 2-Example 2; please refer to Figure 1 , indicating that the fluorescent probe 1 molecule has the strongest light absorption ability at around 340nm, and that the fluorescent probe 2 molecule has the strongest light absorption ability at around 330nm.
[0075] Figure 2 A fluorescence emission spectrum of a water-soluble fluorescent probe provided in Example 1 and Example 2 of the present application; wherein 1-Example 1, 2-Example 2; see Figure 2 , indicating that the fluorescent probe 1 molecule has the strongest luminescence ability at around 550nm, and that the fluorescent probe 2 molecule has the strongest luminescence ability at around 330nm.
[0076] Latent fingerprint imaging
[0077] The application of water-soluble fluorescent probe in latent fingerprint imaging demonstrates the feasibility of using the water-soluble organic fluorescent probe prepared in the above Example 1 as a latent fingerprint developer, including: contacting a solution containing the fluorescent probe with a carrier containing a latent fingerprint, so that the fluorescent probe is aggregated at the ridge of the latent fingerprint; the fluorescent probe aggregated at the ridge of the latent fingerprint emits fluorescence under ultraviolet light excitation to achieve fluorescent imaging of the latent fingerprint.
[0078] The contact method is chemical impregnation, which is as follows: Use an electronic balance to accurately weigh a certain mass of 1 fluorescent probe molecule and dissolve it in 20 ml of pure water solution. At room temperature, ultrasonic dissolution is used to dissolve the solid completely to obtain a concentration of 1×10 -4M latent fingerprint developer, collect latent fingerprints from different substrates by solution immersion method. Take a small amount of the above solution and gently drop it on the latent fingerprint to be tested, irradiate it with a 3W 365nm ultraviolet hand lamp, and take a photo with a mobile phone to obtain the fingerprint image. Figure 3 A water-soluble fluorescent probe provided in Example 1 of the present application uses a chemical immersion method to image a fluorescent image of a latent fingerprint; see Figure 3 , showing strong green fluorescence.
[0079] The contact method is the spray method: use an electronic balance to accurately weigh a certain mass of 1 fluorescent probe molecule and dissolve it in 20 ml of pure water solution. At room temperature, ultrasonic dissolution is used to dissolve the solid completely to obtain a concentration of 1×10 -4 M latent fingerprint developer, collect latent fingerprints on different substrates by spraying. Add a small amount of solution to the atomizer, spray the atomized liquid on the latent fingerprint to be tested in step (b) for about 5 to 10 seconds, irradiate with a 3W 365nm ultraviolet hand lamp, and take a photo with a mobile phone to obtain the fingerprint image. Figure 4 A water-soluble fluorescent probe provided in Example 1 of the present application is used to image a fluorescent image of a latent fingerprint using a spray method; see Figure 4 , showing green fluorescence. The spray method has a slightly worse developed image because the spraying uniformity is not as good as the chemical immersion method.
[0080] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:
[0081] (1) The fluorescent molecules provided in the embodiments of the present application can realize rapid real-time development of latent fingerprints within a few seconds at room temperature;
[0082] (2) The aqueous solution of fluorescent molecules provided in the embodiments of the present application is operator-friendly, non-toxic, harmless to the environment, and does not produce biological or chemical products;
[0083] (3) The fluorescent molecule provided in the embodiments of the present application is a new type of aggregation-induced luminescence molecule in terms of molecular structure, which can be easily water-soluble and functionally modified, has stronger fat affinity and sensitivity, and can achieve a detection level with extremely high sensitivity for latent fingerprints.
[0084] 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 water-soluble fluorescent probe, characterized in that: The water-soluble 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 of Ar1, and R1 is an alkyl substituted tertiary amine group; Ar2 is an aromatic ring; R2 is a substituent at any position of Ar2, and R2 is a hydrophilic group.
2. The water-soluble fluorescent probe according to claim 1, characterized in that The R1 is one of the following: a cyclic alkyl substituted tertiary amine group, a linear alkyl substituted tertiary amine group.
3. The water-soluble fluorescent probe according to claim 2, characterized in that: The cyclic alkyl substituted tertiary amine group is one of the following:
4. The water-soluble fluorescent probe according to claim 2, characterized in that: The linear alkyl-substituted tertiary amine group is one of the following: dodecyl dimethyl tertiary amine and octadecyl dimethyl tertiary amine.
5. The water-soluble fluorescent probe according to claim 1, characterized in that The Ar1 is one of the following: a benzene ring, a naphthalene ring, or thiophene.
6. The water-soluble fluorescent probe according to claim 1, characterized in that The Ar2 is one of the following: a benzene ring, a naphthalene ring, pyridine, an onium salt of pyridine, or an onium salt of quinoline.
7. The water-soluble fluorescent probe according to claim 1, characterized in that: The R2 is one of the following: Ionic groups, hydroxyethyl, polyethylene glycol.
8. Use of the water-soluble fluorescent probe according to any one of claims 1 to 7 in latent fingerprint imaging.
9. The use according to claim 8, 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.
10. The use according to claim 8, characterized in that: The contacting method includes one of the following: a spray method and a chemical immersion method.