CN-117264625-B - Redispersible powder loaded with fluorescent molecules and application thereof in fingerprint imaging

Abstract

The invention discloses a redispersible powder loaded with fluorescent molecules and application thereof in fingerprint imaging, the redispersible powders include EVA latex, water-soluble NIR-II fluorescent dye, and polyvinyl alcohol. The application is the application of redispersible powders in fingerprint imaging. According to the redispersible powder, EVA is selected as a carrier of the water-soluble NIR-II fluorescent dye, so that the luminous characteristics of the water-soluble NIR-II fluorescent dye are completely reserved, the luminous effect of fluorescence can be effectively improved, and the NIR-II fluorescent development of fingerprints on the surfaces of different materials is realized.

Inventors

• ZHENG JIN
• XU QIFENG
• ZHANG JIYANG
• HAO BIN
• ZHU LILIANG

Assignees

• 虹石(江苏)新材料科技有限公司

Dates

Publication Date

20260508

Application Date

20230808

Claims (9)

1. 1. A redispersible powder loaded with fluorescent molecules, characterized in that it comprises EVA latex, a water-soluble NIR-II fluorescent dye and polyvinyl alcohol.
2. 2. Redispersible powder according to claim 1, characterized in that the mass ratio of EVA latex, water-soluble NIR-II fluorescent dye and polyvinyl alcohol is 950:4.75-190:10 on dry matter basis.
3. 3. The redispersible powder of any one of claims 1 to 2, further comprising an anti-caking agent, wherein the anti-caking agent comprises fumed silica.
4. 4. A process for the preparation of a redispersible powder as claimed in any one of claims 1 to 3 comprising the steps of: (1) Dissolving water-soluble NIR-II fluorescent dye in water to obtain fluorescent dye solution; (2) Dissolving polyvinyl alcohol in water to obtain a polyvinyl alcohol solution; (3) Mixing the fluorescent dye solution obtained in the step (1), the polyvinyl alcohol solution obtained in the step (2) and EVA latex, and stirring to obtain a mixed solution; (4) And (3) spray-drying the mixed solution obtained in the step (3), collecting dried powder, and adding an anti-caking agent to obtain the redispersible powder.
5. 5. The process according to claim 4, wherein the anti-caking agent in step (4) is present in an amount of 0.5 to 10% by mass of the redispersible powders.
6. 6. Use of a redispersible powder according to any one of claims 1 to 3 or prepared by a process according to any one of claims 4 to 5 in fingerprint imaging.
7. 7. A fingerprint imaging method comprising the steps of: s1, mixing the redispersible powder of any one of claims 1 to 3 or the redispersible powder prepared by the preparation method of any one of claims 4 to 5 with ethanol, and dissolving to obtain a mixed solvent; S2, spraying the mixed solvent obtained in the step S1 on the surface of an object to be imaged, and drying to obtain the surface of the object containing the redispersible powder; And S3, irradiating the surface of the object containing the redispersible powder obtained in the step S2 by using laser to obtain fingerprint lines.
8. 8. The fingerprint imaging method of claim 7, wherein the mass ratio of redispersible powder to ethanol in step S1 is 1:5-15.
9. 9. The fingerprint imaging method of claim 8, wherein the object to be imaged in step S2 is one of plastic and glass.

Description

Redispersible powder loaded with fluorescent molecules and application thereof in fingerprint imaging Technical Field The invention relates to the technical field of fingerprint detection, in particular to fluorescent molecule-loaded redispersible powder and application thereof in fingerprint imaging. Background The uniqueness of fingerprints makes them very important in forensic surveys. Among them, in existing crime scene fingerprints, the invisible nature of the latent fingerprint is the most difficult part to identify. In recent years, researchers have developed several new methods for latent fingerprint detection, such as chemical smoke methods, multi-metal deposition methods, and fluorescent staining methods. However, the complex and expensive preparation routes, potential toxicity, destructive testing procedures, and poor stability in practical environments limit their further use. Therefore, there is an urgent need to develop a new strategy for simple, low-toxicity potential fingerprint detection. Near infrared two-region (NIR-II, 1000-1700 nm) fluorescent dye is widely applied to the fields of biosensing, optical imaging and the like as an organic optical material with great clinical transformation potential due to good biocompatibility, excellent chemical structure stability and convenient regulation and control of optical properties. However, the inherent hydrophobicity of the conjugated backbone of the fluorescent dye causes it to easily cause fluorescence quenching in an aggregated state, which hinders further applications of the NIR-II fluorescent dye. In recent years, researchers have developed some NIR-II fluorochromes with better fluorescence brightness in aqueous or solid phases through structural regulation of fluorochromes. However, compared with chemical structure modification (such as introduction of steric hindrance group, side chain modification, etc.) to regulate the aggregation state optical performance of fluorescent molecules, the method for reducing intermolecular interaction by compounding a specific material with fluorescent dye in a non-covalent bond action mode, so as to improve fluorescence brightness of the material is a simpler and cheaper method. The vinyl acetate-ethylene copolymer emulsion (EVA emulsion for short) is a polymer emulsion obtained by taking vinyl acetate and ethylene monomer as basic raw materials and carrying out free radical polymerization. The use of EVA latex to improve fluorescent dye development has not been searched for. Disclosure of Invention The invention aims to provide fluorescent molecule-loaded redispersible powder and application thereof in fingerprint imaging, wherein EVA is selected as a carrier of water-soluble NIR-II fluorescent dye, so that the luminous characteristics of the water-soluble NIR-II fluorescent dye are completely reserved, the luminous effect of fluorescence can be effectively improved, and the NIR-II fluorescent development of fingerprints on surfaces of different materials is realized. In order to achieve the above purpose, the present invention adopts the following technical scheme: A redispersible powder loaded with fluorescent molecules comprising EVA latex, water soluble NIR-II fluorescent dye and polyvinyl alcohol. Preferably, the water-soluble NIR-II fluorescent dye comprises 4, 9-bis (6-hexyltrimethylammonium bromide) -9H-fluoren-2-yl) thienyl) -6, 7-bis (4-hexyloxy) phenyl) - [1,2,5] thiadiazole [3,4-g ] quinoxaline (Q-TTQF). Preferably, the mass ratio of the EVA latex, the water-soluble NIR-II fluorescent dye and the polyvinyl alcohol is 950:4.75-190:10 based on dry matter. In the present invention, the dry matter is measured in dry weight of the matter, and the solvent contained therein is not considered. Preferably, the redispersible powder further comprises an anti-caking agent. The anti-caking agent in the present invention comprises fumed silica. The invention also provides a preparation method of the redispersible powder, which comprises the following steps: (1) Dissolving water-soluble NIR-II fluorescent dye in water to obtain fluorescent dye solution; (2) Dissolving polyvinyl alcohol in water to obtain a polyvinyl alcohol solution; (3) Mixing the fluorescent dye solution obtained in the step (1), the polyvinyl alcohol solution obtained in the step (2) and EVA latex, and stirring to obtain a mixed solution; (4) And (3) spray-drying the mixed solution obtained in the step (3), collecting dried powder, and adding an anti-caking agent to obtain the redispersible powder. Preferably, the mass percentage of the fluorescent dye solution in the step (1) is 10%. Preferably, the mass percentage of the polyvinyl alcohol solution in the step (2) is 20%. Preferably, the anti-caking agent in step (4) is 0.5-10%, further preferably 1-8%, most preferably 5% by mass of the redispersible powder. The invention also provides application of the redispersible powder in fingerprint imaging. The invention also provides a finger