Preparation of fluorescer for visualizing latent fingermark on viscous surface of adhesive tape

Abstract

The invention relates to a method for preparing a fluorescer for showing potential fingerprint through the viscous side of adhesive tap and belongs to the field of fingerprint identification technology. The method comprises the following steps: distilled water, sodium sulfite and selenium powder are added to a first vessel and is deoxidized and is heated and reflows in a water bath to obtain a seleno sodium sulfite aqueous solution; after deionized water is added to a second vessel for deoxidization, cadmium chloride and a sulfhydryl compound are added to the vessel; the PH value of the mixture is regulated; the seleno sodium sulfite aqueous solution is added to the vessel and reflows in boiling water to obtain a cadmium selenide nanocrystal solution; after the deionized water is added to a third vessel for deoxidization, the cadmium chloride and the sulfhydryl compound are added to the vessel; the PH value of the mixture is regulated; and the obtained solution is added to the cadmium selenide nanocrystal solution, is dripped with an equimolar sodium sulfide aqueous solution and reflow in boiling water to obtain the fluorescer. The method has a simple process and available materials; and the fluorescer has perfect showing efficiency, sensitivity, accuracy and repeatability and wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of fingerprint identification, and in particular relates to a method for preparing a fluorescent agent for displaying potential fingerprints on adhesive tape adhesive surfaces. The nano fluorescent material prepared by the method has strong selective binding ability to potential fingerprint residues and High fluorescence performance. Background technique [0002] Mudra is the skin pattern of human hands, including mastoid pattern (fingerprint, knuckle pattern and palm pattern), flexor folds, wrinkles and scars on the palm surface. Fingerprints can be regarded as the first evidence, which is of great significance and role in providing investigation direction and finally designating criminal suspects. At present, in many crime scenes (such as kidnapping, explosion, etc.), tapes carrying fingerprint information are left behind, so exploring new simple, efficient, accurate and safe display methods has become an...

AI Technical Summary

Problems solved by technology

Their shortcomings are that the fluorescence performance (fluorescence intensity, fluorescence lifetime, anti-bleaching ability, Stokes shift, etc.) sometimes cannot meet the requirements of old fingerprints, poor selective binding ability with fingerprint residues, strong toxicity

[0006] However, there are still some problems that need to be further solved in the field of potential fingerprint applications of this kind of materials: for example, the preparation cost of some new-type visualization reagents is high, the operation is complicated, the stability of the reagent is lacking, the selective combination with fingerprint residues is poor, and the clarity of the lines And details are easily covered up; in addition, for the latent fingerprints on the tape sticky surface that are more common in crime scenes, the existing nano-type and non-nano-type visualization reagents have insufficient visualization effects

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