A cucurbit ring-based solid fluorescent material and its preparation and application

Abstract

The present invention discloses a cucurbitacin-based solid fluorescent material and its preparation and application. The cucurbitacin-based solid fluorescent material is self-assembled in a hydrochloric acid solution using an eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate as raw materials. The cucurbitacin-based solid fluorescent material of the present invention is a novel fluorescent material that can be used for visualizing latent fingerprints. The cucurbitacin-based solid fluorescent material of the present invention has the characteristics of high contrast, high sensitivity, good selectivity, non-toxicity, simple preparation and application methods, and low cost.

Description

Technical Field

[0001] The present invention relates to a fluorescent material and preparation and application thereof, in particular to a cucurbitacin-based solid fluorescent material and preparation and application thereof. Background Art

[0002] Fingerprints are unique characteristics of each person and are unique and stable throughout a person's life. Therefore, fingerprints are considered important evidence for identifying personal information.

[0003] Because fingers secrete sweat and oil, they leave marks when they touch objects in daily life. Without any treatment, these marks are almost invisible to the naked eye, forming latent fingerprints (LFPs). LFPs are the most common type of fingerprint at crime scenes and are crucial physical evidence in criminal investigations. Therefore, the visualization and rapid collection of LFPs are crucial for identifying criminals in criminal cases.

[0004] Currently, several traditional methods, including powder visualization, fumigation, and chemical staining, have been established and widely used in specific situations. Powder visualization is currently the simplest and most commonly used method. However, these traditional methods have limitations, such as low contrast, low sensitivity, poor selectivity, and high toxicity.

[0005] Fingerprint visualization methods based on fluorescent materials have attracted widespread attention due to their higher contrast and lower background interference compared to traditional methods. However, fingerprint visualization fluorescent materials based on cucurbit rings have not been reported. Summary of the Invention

[0006] The present invention provides a cucurbitacin-based solid fluorescent material and its preparation and application. The cucurbitacin-based solid fluorescent material is a novel fluorescent material that can be used for visualizing latent fingerprints. The cucurbitacin-based solid fluorescent material has the characteristics of high contrast, high sensitivity, good selectivity, non-toxicity, simple preparation and application methods, and low cost.

[0007] The technical solution of the present invention is a cucurbitacin-based solid fluorescent material, the crystal structure of which is as follows:

[0008]

[0009] A preparation method of the aforementioned cucurbitacin-based solid fluorescent material is to use eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate as raw materials and to obtain the material by self-assembly in a hydrochloric acid solution.

[0010] The preparation method of the aforementioned cucurbitacin-based solid fluorescent material comprises the following steps: mixing an eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate, adding a hydrochloric acid solution, heating to completely dissolve the mixture, cooling the mixture to room temperature, allowing the mixture to stand for crystallization, and filtering the mixture to obtain yellow crystals, which are the cucurbitacin-based solid fluorescent material.

[0011] In the aforementioned method for preparing the cucurbitacin-based solid fluorescent material, the molar ratio of the eight-membered cucurbitacin to trisodium 8-hydroxypyrene-1,3,6-trisulfonate is greater than 1:2.

[0012] In the aforementioned method for preparing the cucurbitacin-based solid fluorescent material, the concentration of the hydrochloric acid solution is 6 mol / L.

[0013] An application of the aforementioned cucurbitacin-based solid fluorescent material in latent fingerprint visualization.

[0014] The aforementioned cucurbitacin-based solid fluorescent material is used in the visualization of latent fingerprints. The specific application method is as follows: the cucurbitacin-based solid fluorescent material and montmorillonite powder are mixed to prepare fluorescent fingerprint powder, and then after washing hands, the hands are lightly tapped and pressed on the surface of a test substrate to obtain a latent fingerprint sample to be analyzed; the fluorescent fingerprint powder is taken and covered on the latent fingerprint sample, and the unbound excess powder is gently blown away to obtain a fingerprint visible to the naked eye.

[0015] The aforementioned cucurbitacin-based solid fluorescent material is used in the visualization of latent fingerprints. When the fingerprint visible to the naked eye is irradiated with an ultraviolet lamp with a wavelength of 365nm, the fingerprint surface presents bright green visible light, and a high-resolution latent fingerprint fluorescent image can be obtained by photographing it with a camera.

[0016] A fluorescent fingerprint powder containing the cucurbitacin-based solid fluorescent material according to claim 1, comprising the cucurbitacin-based solid fluorescent material and montmorillonite powder, wherein the mass percentage of the cucurbitacin-based solid fluorescent material is 1-20%.

[0017] The fluorescent fingerprint powder of the aforementioned cucurbitacin-based solid fluorescent material is obtained by mixing the cucurbitacin-based solid fluorescent material and montmorillonite powder in proportion, grinding them uniformly, and vacuum drying them at 30-100°C.

[0018] Beneficial effects of the present invention

[0019] 1. The present invention prepares a new type of solid fluorescent material by using eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate as raw materials. The preparation method of the solid fluorescent material of the present invention is simple and the preparation cost is low.

[0020] 2. The solid fluorescent material of the present invention can be used as a visualization reagent for latent fingerprints. When used, it has the advantages of high contrast, high sensitivity, good selectivity, non-toxicity and simple application method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attachment Figure 1 A stacking diagram of the single crystal structure of the cucurbitacin-based solid fluorescent material of the present invention;

[0022] Attachment Figure 2 The molecular structure formula of the eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate of the present invention;

[0023] Attachment Figure 3 is the fluorescence emission spectrum of the cucurbitacin-based solid fluorescent material of the present invention in a solid state;

[0024] Attachment Figure 4 The fingerprint images and image resolution comparison of montmorillonite powder compounded with cucurbitacin-based solid fluorescent materials in different mass ratios;

[0025] Attachment Figure 5 The fingerprint development images and grayscale comparison images of the fingerprint powder prepared by combining the cucurbitacin-based solid fluorescent material and montmorillonite powder of the present invention with a mass ratio of 5% after being placed for 1 day, 7 days, and 15 days respectively;

[0026] Attachment Figure 6 To visualize the local detail features of latent fingerprints using the fingerprint powder of the present invention;

[0027] Attachment Figure 7 Visualization of latent fingerprint images on different substrates (365nm UV illumination above, natural light below). DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the examples, but they are not intended to limit the present invention.

[0029] Embodiments of the present invention

[0030] Example 1:

[0031] Preparation of cucurbitacin-based solid fluorescent materials

[0032] (1) 10.0 mg of eight-membered cucurbitacin and 10.0 mg of trisodium 8-hydroxypyrene-1,3,6-trisulfonate were mixed and 6 mol / L hydrochloric acid solution was added. The mixture was ultrasonicated, stirred, and heated to completely dissolve the mixture to obtain solution A.

[0033] (2) Solution A was cooled to room temperature and allowed to stand at room temperature for 1 day, and yellow crystals were observed to precipitate;

[0034] (3) The yellow crystals were structurally tested using a Bruker D8 VENTURE single crystal diffractometer to determine their molecular configuration and assembly pattern. Figure 1 and 2 As shown;

[0035] (4) Filter, wash and dry to collect and obtain the yellow crystal material, which is the cucurbitacin-based solid fluorescent material (HPTS@Q[8]). Figure 3 The solid fluorescent material emits strong blue-green fluorescence under 365nm ultraviolet light.

[0036] Example 2:

[0037] Preparation of cucurbitacin-based solid fluorescent materials

[0038] (1) 20.0 mg of eight-membered cucurbitacin and 28.0 mg of 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt were mixed and 6 mol / L hydrochloric acid solution was added and heated to completely dissolve to obtain solution A;

[0039] (2) Solution A was cooled to room temperature and allowed to stand for 2 days to evaporate, and yellow crystals were observed to precipitate;

[0040] (3) centrifugally filtering to collect yellow crystals, washing and drying to obtain a yellow crystalline material which is a cucurbitacin-based solid fluorescent material.

[0041] Example 3:

[0042] Preparation of fluorescent fingerprint powder by combining HPTS@Q[8] with montmorillonite

[0043] 0.5 mg HPTS@Q[8] and 49.5 mg montmorillonite powder were thoroughly mixed by grinding and dried in vacuum at 60 °C to obtain a composite fluorescent fingerprint powder with a mass ratio of 1%.

[0044] Example 4:

[0045] Preparation of fluorescent fingerprint powder by combining HPTS@Q[8] with montmorillonite

[0046] 1.5 mg HPTS@Q[8] and 48.5 mg montmorillonite powder were thoroughly mixed by grinding and dried in vacuum at 30 °C to obtain a composite fluorescent fingerprint powder with a mass ratio of 3%.

[0047] Example 5:

[0048] Preparation of fluorescent fingerprint powder by combining HPTS@Q[8] with montmorillonite

[0049] 2.5 mg HPTS@Q[8] and 47.5 mg montmorillonite powder were thoroughly mixed by grinding and dried in vacuum at 40 °C to obtain a composite fluorescent fingerprint powder with a mass ratio of 5%.

[0050] Example 6:

[0051] Preparation of fluorescent fingerprint powder by combining HPTS@Q[8] with montmorillonite

[0052] 5.0 mg HPTS@Q[8] and 45.0 mg montmorillonite powder were thoroughly mixed by grinding and dried in vacuum at 70 °C to obtain a composite fluorescent fingerprint powder with a mass ratio of 10%.

[0053] Example 7:

[0054] Preparation of fluorescent fingerprint powder by combining HPTS@Q[8] with montmorillonite

[0055] 10.0 mg HPTS@Q[8] and 40.0 mg montmorillonite powder were thoroughly mixed by grinding and dried in vacuum at 100 °C to obtain a composite fluorescent fingerprint powder with a mass ratio of 20%.

[0056] Example 8:

[0057] HPTS@Q[8] and montmorillonite composite fluorescent fingerprint powder for visualization of latent fingerprints

[0058] (1) Wash your hands thoroughly with soap or hand sanitizer and dry them. After lightly touching your forehead with your fingertips, gently press them onto common substrates such as tin foil, glass, stainless steel, wood, plastic, ceramic, aluminum alloy, etc. After a few seconds, lift your hands to obtain latent fingerprint samples.

[0059] (2) Dip a soft brush in an appropriate amount of fluorescent fingerprint powder and gently shake it off with your fingers on the surface where the latent fingerprint is located. Use an ear bulb to gently blow away the excess fluorescent fingerprint powder. A clear fingerprint image can be seen with the naked eye under a fluorescent light.

[0060] (3) Using a 365nm ultraviolet light source to illuminate the fingerprint area on the surface of different substrates, the fingerprint lines clearly show bright green fluorescence, and high-resolution fingerprint images are collected and photographed using a smartphone;

[0061] (4) As attached Figure 4 As shown, the composite fluorescent fingerprint powder with a mass ratio of 5% has the best resolution and contrast, but even the composite fluorescent fingerprint powder with a mass ratio of 1% can obtain a complete and clear-resolution fingerprint fluorescence image;

[0062] (5) As attached Figure 5 As shown, after the fluorescent fingerprint powder was placed at room temperature for 1 day, 7 days, and 15 days and then used to visualize latent fingerprints, high-resolution and high-contrast fingerprint images were still obtained;

[0063] (6) As attached Figure 6 As shown, the high-resolution fluorescent fingerprint image includes the 1-3 level detail features of the fingerprint;

[0064] (7) As attached Figure 7 As shown, clear fluorescent fingerprint images can be obtained on different substrate surfaces.

[0065] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a cucurbitacin-based solid fluorescent material, characterized in that: Mixing an eight-membered cucurbitacin and trisodium 8-hydroxypyrene-1,3,6-trisulfonate, then adding a hydrochloric acid solution, heating to completely dissolve the mixture, cooling to room temperature, standing to crystallize, and filtering to obtain yellow crystals, which are the cucurbitacin-based solid fluorescent material; The mass ratio of the eight-membered cucurbitacin to trisodium 8-hydroxypyrene-1,3,6-trisulfonate is 1:1 or 1:1.4; The concentration of the hydrochloric acid solution is 6 mol / L.

2. Use of the cucurbitacin-based solid fluorescent material prepared according to the method of claim 1 in latent fingerprint visualization.

3. The use of the cucurbitacin-based solid fluorescent material according to claim 2 in latent fingerprint visualization, characterized in that: The specific application method is as follows: a cucurbitacin-based solid fluorescent material and montmorillonite powder are mixed to prepare fluorescent fingerprint powder; then, after washing hands, the hands are lightly tapped on the forehead and pressed on the surface of a test substrate to obtain a latent fingerprint sample to be analyzed; the fluorescent fingerprint powder is covered on the latent fingerprint sample, and the unbound excess powder is gently blown away to obtain a fingerprint visible to the naked eye.

4. The use of the cucurbitacin-based solid fluorescent material according to claim 3 in latent fingerprint visualization, characterized in that: The fingerprint visible to the naked eye is irradiated with an ultraviolet lamp having a wavelength of 365 nm, and the fingerprint surface presents bright green visible light. A high-resolution fluorescent image of the latent fingerprint can be obtained by photographing it with a photographing device.

5. A fluorescent fingerprint powder containing a cucurbitacin-based solid fluorescent material prepared by the method of claim 1, characterized in that: The invention consists of a cucurbit ring-based solid fluorescent material and montmorillonite powder, wherein the mass percentage of the cucurbit ring-based solid fluorescent material is 1-20%.

6. The fluorescent fingerprint powder of the cucurbit ring-based solid fluorescent material according to claim 5, characterized in that: The fluorescent fingerprint powder is obtained by mixing cucurbitacin-based solid fluorescent material and montmorillonite powder in proportion, grinding them uniformly, and vacuum drying them at 30-100° C.

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