Water-soluble aie functional molecules and their application in latent fingerprint imaging

Abstract

The application belongs to the field of latent fingerprint imaging, and more particularly relates to a preparation method of a water-soluble AIE functional molecule and application thereof in latent fingerprint imaging. The water-soluble AIE molecule has the following general structural formula: wherein R1 is triphenylamine, N-phenylcarbazole, N-phenylphenothiazine, N-phenylphenoxazine, 10H-phenoselenoxazine or 10-phenyl-10H-phenoselenoxazine; Ar l is an onium salt containing pyridine, quinoline or isoquinoline. The prepared developer has simple preparation method, high aggregate state luminescent efficiency, fast latent fingerprint imaging speed, high detection sensitivity and imaging resolution, and excellent latent fingerprint imaging effect on strong spontaneous light substrates, dark substrates, rough surface substrates, semi-absorptive substrates and absorptive substrates.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of latent fingerprint imaging, and more particularly relates to a preparation method of a water-soluble AIE functional molecule and its application in latent fingerprint imaging. BACKGROUND

[0002] Fingerprint usually presents unique and unique characteristics. Latent fingerprint is an imprint with fingerprint characteristics formed by sweat gland secretions adhering to the surface of the substrate, which is used to identify the identity of criminal suspects in forensic investigation, and plays an important role in case investigation and litigation. Fingerprint details are usually defined as three levels. Among them, the first level of detail is the macroscopic feature of fingerprint context, including arch, spiral, triangular line, center point, etc. The second level of detail belongs to the macroscopic feature of fingerprint ridge and fingerprint groove, including bifurcation, island, end point, ridge point, rift valley and wrinkle, etc. The third level of detail includes ridge width, ridge edge shape, ridge angle, pore, pore spacing, etc., which belongs to the microscopic detail of fingerprint ridge and fingerprint groove. The first level of detail is usually not unique enough to distinguish individual characteristics, while the second and third levels of detail can fully reflect the differences in individual characteristics. In forensic identification, the third level of detail is considered as the gold standard for identity discrimination (J. Am. Chem. Soc. 2020, 142, 7497; J. Am. Chem. Soc. 2024, 146, 2072).

[0003] Traditional latent fingerprint imaging methods include physical imaging methods such as brush powder, immersion, fumigation and spraying, and chemical imaging methods. Among them, the brush powder method is the most direct and easy to implement, and is widely used. However, the traditional physical imaging method represented by the brush powder method has many drawbacks, such as poor selectivity and low imaging contrast. In order to remove excess developer, the post-dusting process of the brush powder method easily damages the fingerprint details, and the inevitable dust also poses a threat to the health of the test personnel. The chemical imaging method based on iodine, indantrione or silver nitrate and the fumigation method have slow imaging speed, and have potential hazards to the skin, mucous membrane and even DNA (Adv. Mater. 2023, 35(20), 2211917; Adv Mater 2022, 34(35), 2202540).

[0004] In recent years, the immersion method and the spray method gradually replace the brush powder method in the field of latent fingerprint imaging. Researchers have developed many new organic luminescent materials with excellent performance for latent fingerprint development, including aggregation-induced emission (AIE) materials. Because the immersion method and the spray method can better protect the details of the fingerprint and avoid the operator inhaling powder. AIE functional molecules usually have good solid-state luminescent performance, and their inherent lipophilicity helps to adhere to the latent fingerprint, improving the imaging resolution. Lipophilic functional molecules need organic solvents to help dissolve, and organic solvents will dissolve and destroy the details of the latent fingerprint to some extent, and even cause the latent fingerprint to collapse. Therefore, it is of great significance and practical value to develop water-soluble AIE functional molecules with simple structure as latent fingerprint developing agents.

[0005] Patent CN112852409A discloses a latent fingerprint developing agent based on AIE functional molecules and its preparation method and application. The AIE functional molecules are dispersed in water using a surfactant to obtain a latent fingerprint developing solution. The latent fingerprint is imaged by immersing the substrate with latent fingerprints and using hydrophobic-hydrophobic interaction and electrostatic adsorption principle. The latent fingerprint developing agent has simple preparation process, small biological toxicity, fast imaging speed, and good application effect. Patent CN116003380A discloses a latent fingerprint developing agent. A series of latent fingerprint developing agents are designed and synthesized by introducing an electron donor to the para position of the quaternary ammonium pyridine nitrogen atom. The molecule has amphiphilicity by introducing a hydrophobic end and a hydrophilic end, and is adsorbed on sebum secretion through hydrophobic interaction to realize latent fingerprint imaging. The latent fingerprint developing agent is simple to synthesize, and the developing solution is prepared with water as the carrier to realize the visualization of the details of the fingerprint features. Patent CN113582931A discloses a preparation method of a fluorescent probe based on the green fluorescent protein chromophore skeleton structure and its application in latent fingerprint imaging. The fluorescent probe can be dissolved in water and can quickly image the latent fingerprint on the object within 30s through ultrasonic atomization, is not affected by the collection background, and does not affect the latent fingerprint.

[0006] However, the above-mentioned latent fingerprint developing agents have some defects in use. For example, the AIE functional molecule disclosed in patent CN112852409A does not have water solubility and needs to be dispersed in water with the help of a surfactant. The non-dissolved AIE functional molecule particles are large, which can easily cause uneven imaging effect. Moreover, the use of surfactants can also damage the details of the fingerprint, resulting in reduced imaging resolution. The latent fingerprint developing agents disclosed in patents CN112852409A and CN116003380A both need to implement latent fingerprint imaging by immersion method. Due to the restriction of the volume of the container, it is difficult to implement latent fingerprint imaging in situ by immersion method for large-volume objects or vertical surfaces. The latent fingerprint developing agent disclosed in patent CN113582931A uses an ultrasonic atomizer to implement latent fingerprint imaging in a spraying manner. However, the 3rd level fingerprint details cannot be directly captured by a digital camera or a mobile phone, and the analysis and identification of the 3rd level fingerprint details need to be completed by using an optical microscope. SUMMARY

[0007] The present application aims to overcome the shortcomings of the prior art and provides a water-soluble AIE functional molecule and a preparation method thereof, which is used as a developing agent for latent fingerprint imaging. The prepared developing agent has a simple preparation method, high aggregation state luminescence efficiency, fast latent fingerprint imaging speed, high detection sensitivity and imaging resolution, and excellent latent fingerprint imaging effect on strong spontaneous light substrates, dark substrates, rough surface substrates, semi-adsorbed substrates and adsorbed substrates.

[0008] The present application also provides an application of the water-soluble AIE functional molecule in latent fingerprint imaging.

[0009] To solve the above technical problems, the present application is implemented as follows:

[0010] A water-soluble AIE functional molecule has the following general structure:

[0011]

[0012] wherein R1 is

[0013]

[0014] Ar1 is an onium salt containing pyridine, quinoline or isoquinoline.

[0015] Further, Ar1 is:

[0016]

[0017] wherein R2 is:

[0018]

[0019] The X is Cl, Br or I; the n is any natural number between 0 and 10.

[0020] Further, the Ar1 is:

[0021] R2 is The n is 0, 1 or 2.

[0022] Further, the R1 is

[0023] Further, the R1 is The Ar1 is: The preparation method of the water-soluble AIE functional molecule above comprises the following steps:

[0024] (1) Synthesis of CziQn

[0025] Into a mixed solution of tetrahydrofuran and deionized water, 6-bromoisoquinoline, K2CO3, Pd(PPh3)4 and (9-phenyl-9H-carbazol-3-yl)boronic acid are sequentially added, and the reaction is stirred and refluxed; after the reaction is completed, saturated brine is added and the mixture is extracted, the organic phases are combined, and column chromatography is used for separation, to obtain CziQn.

[0026] (2) Synthesis of CziQn-OH

[0027] Into acetonitrile, CziQn and 2-bromoethanol are added, and the reaction is stirred; after the reaction is completed, the solvent is removed by rotary evaporation, and column chromatography is used for separation, to obtain the target product, the water-soluble AIE functional molecule CziQn-OH.

[0028] Further, in step (1), the volume ratio of tetrahydrofuran to deionized water is 3:1; the reaction is stirred and refluxed under a nitrogen atmosphere for 24 hours; in step (2), the reaction is stirred at 90°C under a nitrogen atmosphere for 24 hours.

[0029] Further, in steps (1) and (2), the eluent used for column chromatography separation is a mixture of dichloromethane and methanol. The volume ratio of dichloromethane to methanol is 10-100:1.

[0030] The application of the water-soluble AIE functional molecule above in latent fingerprint development can be implemented according to the following steps:

[0031] (1) The water-soluble AIE functional molecule is added to deionized water, and after dissolution, a latent fingerprint developing solution is obtained;

[0032] (2) The prepared water-soluble AIE functional molecule latent fingerprint developing solution is added to a medicine cup of a compressed atomizer, the nozzle of the medicine cup is sprayed onto the surface of a substrate where the latent fingerprint is located, and then latent fingerprint imaging and latent fingerprint luminescence searching are performed under ultraviolet light irradiation.

[0033] Further, the substrate is one of stainless steel, glass, ceramic, wood, leather, plastic, copper or paper.

[0034] The water-soluble latent fingerprint developing agent in the present application has simple preparation method and high aggregate state luminescence efficiency. The developing solution prepared by using water as solvent can be sprayed on various substrates by using a compression type atomizer to implement latent fingerprint imaging. The latent fingerprint imaging can be completed within 10 seconds, the imaging speed is fast, and the latent fingerprint imaging effect on strong spontaneous light substrates, dark substrates, rough surface substrates, semi-absorptive substrates and absorptive substrates is excellent. The detection sensitivity and imaging resolution are high, the water-soluble latent fingerprint developing agent is non-toxic and harmless, has practical application value, and can replace traditional black developing powder and silver developing powder to be used for rapid extraction of fingerprint evidence at a crime scene.

[0035] The present application will be described in detail below through specific embodiments. These embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be completely conveyed to those skilled in the art. As mentioned throughout the specification and claims, "comprising" or "including" is an open term, which is interpreted to mean "including, but not limited to". The subsequent description in the specification is for the purpose of illustrating the preferred embodiments of the present application, and is not intended to limit the scope of the present application. The scope of protection of the present application is defined by the appended claims. Unless otherwise specified, various reagents and materials used in the present application can be purchased from the market. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The synthesis route of the AIE functional molecule prepared for Example 1 of the present application is shown in the schematic diagram.

[0037] Figure 2 The fluorescence emission spectrum of the AIE functional molecule prepared for Example 1 of the present application in water with different acetonitrile contents is shown in the table.

[0038] Figure 3 The latent fingerprint imaging diagram of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for Example 1 of the present application on stainless steel products based on a compression type atomizer is shown in the table.

[0039] Figure 4 The latent fingerprint imaging diagram of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for Example 1 of the present application on glass products based on a compression type atomizer is shown in the table.

[0040] Figure 5 The latent fingerprint imaging diagram of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for Example 1 of the present application on ceramic products based on a compression type atomizer is shown in the table.

[0041] Figure 6Latent fingerprint imaging chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the leather product.

[0042] Figure 7 Latent fingerprint imaging chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the leather product.

[0043] Figure 8 Latent fingerprint imaging chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the plastic product.

[0044] Figure 9 Latent fingerprint imaging chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the copper product.

[0045] Figure 10 Latent fingerprint imaging chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the paper product.

[0046] Figure 11 Fingerprint detail analysis chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the imaging fingerprint photo of the stainless steel product, the copper product and the paper product.

[0047] Figure 12 Latent fingerprint search fragment chart of the latent fingerprint developing solution of the water-soluble AIE functional molecule prepared for the embodiment 1 of the present application based on the compressed atomizer on the plastic product. DETAILED DESCRIPTION

[0048] Embodiment 1

[0049] A water-soluble AIE functional molecule, the name of which is abbreviated as CziQn-OH, wherein R1 is Arl is n is 2. The synthesis path thereof is shown as Figure 1 including the following steps:

[0050] (1) Synthesis of CziQn: To a mixture of tetrahydrofuran / deionized water (30 mL, 3: 1 v:v) was added 6-bromoisoquinoline (2.0 mmol, 0.414 g), K2CO3(4.0 mmol, 0.552 g), Pd(PPh3)4(5.0 mol%, 0.1 mmol, 0.115 g) and (9-phenyl-9H-carbazol-3-yl)boronic acid (2.0 mmol, 0.574 g) sequentially; the mixture was stirred under reflux for 24 h under nitrogen atmosphere. After the reaction was completed, saturated brine (15 mL) was added and the mixture was extracted with ethyl acetate (3 x 15 mL), the organic phases were combined and separated by column chromatography using dichloromethane / methanol (10:1, v:v) as eluent. The resulting CziQn was off-white powder with a yield of 87.7%. 1 H NMR (400 MHz, Chloroform-d) δ 9.29 (s, 1H), 8.55 (d, J = 5.8 Hz, 1H), 8.49 (d, J = 1.5 Hz, 1H), 8.23 (d, 1H), 8.12 - 8.06 (m, 2H), 8.02 (dd, J = 8.5, 1.8 Hz, 1H), 7.78 (dd, J = 8.5, 1.8 Hz, 1H), 7.74 (d, J = 5.8 Hz, 1H), 7.67 - 7.58 (m, 4H), 7.53 - 7.50 (m, 2H), 7.47 - 7.43 (m, 2H), 7.34 (ddd, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 152.1, 144.2, 142.9, 141.5, 140.9, 137.5, 136.5, 132.1, 130.0, 128.2, 127.8, 127.7, 127.4, 127.1, 126.5, 125.7, 124.1, 123.8, 123.3, 120.8, 120.4, 120.3, 119.5, 110.4, 110.1. HRMS (ESI): m / z calc. for C 27 H 18 N2, 370.14700 [M] + , found: 370.14645 [M] + .

[0051] (2) Synthesis of CziQn-OH: To CH3CN (25 mL) was added CziQn (1.0 mmol, 0.370 g), 2-bromoethanol (10.0 mmol, 1.240 g, 0.710 mL), the mixture solution was stirred at 90 °C under nitrogen atmosphere for 24 h. After the reaction was completed, the solvent was removed by rotary evaporation, and separated by column chromatography with dichloromethane / methanol (10:1, V:v) as eluent. The obtained CziQn-OH was bright yellow powder with a yield of 50.7%. 1 H NMR (400 MHz, DMSO-d6) δ 9.97 (s, 1H), 9.00 (s, 1H), 8.86-8.70 (m, 2H), 8.65-8.54 (m, 4H), 8.42 (d, 1H), 8.08 (dq, 1H), 7.78-7.64 (m, 4H), 7.63-7.45 (m, 2H), 7.46-7.34 (m, 2H), 5.30 (t, 1H), 4.77 (t, 2H), 3.98 (q, 2H). 13 C NMR (101 MHz, DMSO) δ 149.5, 148.2, 140.9, 137.7, 136.4, 135.5, 130.9, 130.3, 130.2, 129.4, 128.1, 126.7, 126.1, 125.7, 125.2, 123.8, 123.2, 122.8, 121.0, 120.7, 120.4, 110.6, 110.0, 104.3, 99.5, 62.9, 60.0. HRMS (ESI): m / z calc. for C 29 H 23 BrN2O, 494.09938 [M] + , found: 494.09883 [M] + .

[0052] The preparation method of the latent fingerprint developing solution of the water-soluble AIE functional molecule and the latent fingerprint imaging method in Example 1 of the present application are as follows:

[0053] (1) Prepare a water solution of the water-soluble AIE functional molecule CziQn-OH with a concentration of 100 μM as the latent fingerprint developing solution. Add CziQn-OH (4.95 mg) to deionized water (100 mL) to obtain the latent fingerprint developing solution after fully dissolving.

[0054] (2) Add the prepared latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH with a concentration of 100 μM to the medicine cup of the compressed atomizer, spray the nozzle of the medicine cup to the surface of the substrate where the latent fingerprint is located, and then observe and take a high-definition imaging fingerprint photo under ultraviolet light irradiation.

[0055] Advantages of the present application:

[0056] Figure 2 is the fluorescence emission spectrum of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application in water with different acetonitrile contents. When the acetonitrile content increases from 0% to 90%, the fluorescence intensity gradually increases. It can be seen from Figure 2 that as the acetonitrile content in the solvent system increases, the solubility of CziQn-OH decreases and aggregation occurs, and the fluorescence significantly increases, showing AIE characteristics.

[0057] Figure 3 is the imaging fingerprint photo of the latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application sprayed on a stainless steel product by a compressed atomizer. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as air holes and fingerprint ridge edge details.

[0058] Figure 4 is the imaging fingerprint photo of the latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application sprayed on a glass product by a compressed atomizer. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as air holes and fingerprint ridge edge details.

[0059] Figure 5 is the imaging fingerprint photo of the latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application sprayed on a ceramic product by a compressed atomizer. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as air holes and fingerprint ridge edge details.

[0060] Figure 6 is the imaging fingerprint photo of the latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application sprayed on a wood product by a compressed atomizer. The imaging fingerprint has high contrast and high resolution, and can clearly present 2-level details such as fingerprint bifurcation and end points.

[0061] Figure 7 is the imaging fingerprint photo of the latent fingerprint developing solution of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application sprayed on a leather product by a compressed atomizer. The imaging fingerprint has high contrast and high resolution, and can clearly present 2-level details such as fingerprint bifurcation and end points.

[0062] Figure 8is the imaging fingerprint photo of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as pores, fingerprint ridge edge details, etc.

[0063] Figure 9 is the imaging fingerprint photo of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as pores, fingerprint ridge edge details, etc.

[0064] Figure 10 is the imaging fingerprint photo of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application. The imaging fingerprint has high contrast and high resolution, and can clearly present 3-level details such as pores, fingerprint ridge edge details, etc.

[0065] Figure 11 is the fingerprint detail analysis diagram of the imaging fingerprint photo of the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application. The 1-level details such as center point and triangular point, the 2-level details such as ridge fold, ridge endpoint and ridge bifurcation, and the 3-level details such as pores and ridge edge details are clearly visible; the 3-level details such as pore spacing, ridge width and ridge angle can be accurately measured.

[0066] Figure 12 is the screenshot of the luminescent search of the latent fingerprint on the plastic product by the water-soluble AIE functional molecule CziQn-OH prepared in Example 1 of the present application. The nozzle of the medicine cup continuously sprays the plastic surface where the latent fingerprint is located, and the luminescent search of the latent fingerprint is implemented. The atomizing gas flow continuously sweeps the surface of the substrate, and then uniformly diffuses along the surface to the four directions, forming a continuous sweeping area with an area of about 0.0314 m 2 The latent fingerprint in the sweeping area is dyed due to the continuous contact with the atomizing droplets. Moving the atomizing gas source can increase the sweeping area and change the sweeping position, and the luminescent search process of the latent fingerprint is completed. Figure 12As shown, the latent fingerprints on the plastic surface are gradually dyed under the blowing of the atomized airflow, and the enhanced luminescence signal is presented in real time. The luminescence signal of the imaged fingerprint has sufficient contrast with the matrix, and can be clearly recognized by the naked eye. The search and imaging of the entire latent palm print in the blowing area can be completed quickly within 90s. Compared with the traditional latent fingerprint search method, the luminescence search of the latent fingerprint based on the water-soluble AIE functional molecule CziQn-OH prepared in embodiment 1 of the present application effectively overcomes the interference of objective factors such as detection light angle, matrix material and background color, and avoids the restriction of subjective factors such as the insight and actual experience of criminal investigation personnel. Therefore, the search efficiency of the latent fingerprint can be significantly improved, and the search process is more comprehensive and thorough.

[0067] Compared with the existing technology, the latent fingerprint developer of the present application not only has simple preparation process and convenient operation, but also has small biological toxicity, fast developing speed and high imaging clarity. The outstanding advantages are small consumption (0.26mg / m 2 Without pre-treatment and post-treatment, in-situ latent fingerprint imaging can be realized at the crime scene, and without the use of large optical microscopic equipment, ordinary mobile phones can be used to directly capture the 3-level fingerprint details of the imaged fingerprint and complete fingerprint detail analysis, which is suitable for various scenes. The present application realizes the preparation method of the latent fingerprint developer based on the water-soluble AIE functional molecule and realizes the latent fingerprint imaging and luminescence search of the latent fingerprint through the compressed atomizer, which greatly promotes the development of the latent fingerprint imaging technology and has practical application value.

[0068] Those skilled in the art should understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A water-soluble AIE functional molecule, characterized in that, having the general structure: wherein R1 is: Ar1 is: R2 is n is 1 or 2; and X is CI, Br, or I. 2.The water-soluble AIE functional molecule according to claim 1, characterized in that: R1is: Ar1is: The compound is named as CziQn-OH.

3. A method for preparing the water-soluble AIE functional molecule according to claim 2, characterized in that, The method comprises the following steps: (1) Synthesis of CziQn 6-bromoisoquinoline, K2CO3, Pd(PPh3)4 and (9-phenyl-9H-carbazol-3-yl)boronic acid are sequentially added into a mixed solution of tetrahydrofuran and deionized water, and the reaction is stirred and refluxed; after the reaction is completed, saturated brine is added and the mixture is extracted, the organic phases are combined, and column chromatography is used for separation, to obtain CziQn; (2) Synthesis of CziQn-OH CziQn and 2-bromoethanol are added into acetonitrile, and the reaction is stirred; after the reaction is completed, the solvent is removed by rotary evaporation, and column chromatography is used for separation, to obtain the target product, water-soluble AIE functional molecule CziQn-OH.

4. The method for preparing the water-soluble AIE functional molecule as described in claim 3, characterized in that: In step (1), the volume ratio of tetrahydrofuran to deionized water is 3:1; the reaction is stirred and refluxed under a nitrogen atmosphere for 24 hours; in step (2), the reaction is stirred at 90°C under a nitrogen atmosphere for 24 hours.

5. The method for preparing the water-soluble AIE functional molecule as described in claim 4, characterized in that: In steps (1) and (2), the eluent used for column chromatography separation is a mixture of dichloromethane and methanol; the volume ratio of dichloromethane to methanol is 10-100:

1.

6. Use of the water-soluble AIE functional molecule according to claim 1 or 2 in latent fingerprint development. The following steps are implemented: (1) The water-soluble AIE functional molecule is added into deionized water, and after being dissolved, a water-soluble AIE functional molecule latent fingerprint developing solution is obtained; (2) The prepared water-soluble AIE functional molecule latent fingerprint developing solution is added into a medicine cup of a compressed atomizer, the nozzle of the medicine cup is sprayed onto a substrate surface where a latent fingerprint is located, and then latent fingerprint imaging and latent fingerprint luminescence searching are performed under ultraviolet light irradiation. 7.The use of the water-soluble AIE functional molecule according to claim 6 in latent fingerprint imaging. The substrate is one of stainless steel, glass, ceramic, wood, leather, plastic, copper or paper.

Images