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Rapid latent fingerprint presentation reagent preparation method

A technology of latent fingerprints and reagents, applied in the field of chemical detection, can solve the problems of uneven size distribution of quantum dots, complicated display process, poor display effect, etc., and achieve the effects of adjustability, luminous wavelength, and rapid response

Inactive Publication Date: 2011-06-29
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the method mentioned in Patent No.: US 6,30662 B1 still has the following disadvantages: (1) The size distribution of quantum dots is uneven and uncontrollable, mainly because the PAMAM dendrimer in the patent mainly acts as a stabilizer, while It does not act as a nano-template; (2) The solvent is methanol or a mixed solvent of methanol and water, which can easily dissolve fingerprint residues, resulting in poor display effect, so this display reagent is only suitable for fingerprints contaminated by "502" glue; (3) There are few applicable objects, and it only has a good display effect on non-permeable objects such as aluminum foil and polyethylene; (4) The display process is complicated: the fingerprint needs to be dyed with "502" glue, and the soaking time is as long as 5 to 24 hours. The photographic equipment used is a time-resolved digital camera, which is too expensive

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0046] Example 1: Preparation of CdS quantum dots encapsulated by PAMAM dendrimers

[0047] The preparation method of the present invention is as follows:

[0048] Dilute 100mL concentration to 1×10 -4 mol L -1 Add the aqueous solution of G5.0-PAMAM dendrimers into a 250mL round bottom flask, adjust the pH value to 7.5±-0.2 with hydrochloric acid, and then 2+ To the molar ratio of PAMAM dendrimers (3:1, 5:1, 10:1, 20:1), add 0.01mol L -1 Cadmium chloride (CdCl 2 ) solution, reacted at room temperature for 48h to make Cd 2+ Fully coordinated with PAMAM dendrimers. Rejoin with Cd 2+ 0.01mol·L equivalent to the amount of substance -1 Na 2 S solution was stirred at room temperature for 1 h to make the crystal grains grow stably, and finally the yellow transparent G5.0-AMAM dendrimer-wrapped CdS quantum dots were obtained. Dialysis was carried out with a dialysis bag with a molecular weight cut off of 2,000 to obtain an aqueous solution of CdS quantum dots wrapped in pure ...

Embodiment 2

[0050] Example 2: Preparation of CdS / ZnS core-shell structure quantum dots wrapped by PAMAM dendrimers

[0051] The preparation method of the present invention is as follows:

[0052] Dilute 100mL concentration to 1×10 -4 mol L -1 Add G5.0-PAMAM dendrimer aqueous solution to a 250mL round bottom flask, adjust the pH value to 7.5+0.2 with hydrochloric acid, add 10ml 0.01mol·L -1 Cadmium chloride (CdCl 2 ) solution, reacted at room temperature for 48h to make Cd 2+ Fully coordinated with G5.0-PAMAM dendrimers. Rejoin with Cd 2+ The same 0.01mol·L of the number of moles -1 Na 2 S solution, stirred at room temperature for 1 h to stabilize the growth of CdS grains. Use a syringe at room temperature to alternately add new equimolar amounts of S 2- Solution (0.01mol·L -1 ) and Zn 2+ Solution (0.01mol·L -1 )(Zn 2+ The total number of moles of Cd satisfies 2+ with Zn 2+ molar ratio=1:0, 5:1, 2:3, 4:3, 3:2, 1:5, 1:1) to the CdS quantum dot solution wrapped by PAMAM dendri...

Embodiment 3

[0054] Example 3: Preparation of CdS / CdSe core-shell structure quantum dots wrapped by PAMAM dendrimers

[0055] Se 2- Solution preparation: add 1mL water and 0.04gNaBH in turn to a single-necked flask 4 , gently shake the vial, add 0.0395g Se powder after completely dissolved, shake until all the reactants turn from black to milky white, cover the stopper, put it on a magnetic stirrer, react at a constant temperature at 4°C for 2h, and then dilute it The concentration is 0.01mol·L -1 of aqueous solution.

[0056] Dilute 100mL concentration to 1×10 -4 mol L -1 Add G5.0-PAMAM dendrimer aqueous solution to a 250mL round bottom flask, adjust the pH value to 7.5±0.2 with hydrochloric acid, add 10ml 0.01mol L -1 Cadmium chloride (CdCl 2 ) solution, reacted at room temperature for 48h to make Cd 2+ Fully coordinated with PAMAM dendrimers. Rejoin with Cd 2+ The same 0.01mol·L of the number of moles -1 Na 2S solution, stirred at room temperature for 1 h to stabilize the gro...

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Abstract

The invention discloses a fast latent fingerprint developing reagent and a method for the production thereof belonging to the chemical detection technique field. The fast latent fingerprint developing reagent comprises CdS quantum dots encapsulated by PAMAM dendrimers and CdS / MX core-shell structure quantum dots encapsulated by the PAMAM dendrimers. The synthetic method comprises the following steps: Cd<2+> and the PAMAM dendrimers are coordinated until the coordination is balanced after a PAMAM dendrimer solution is prepared; then an S<2-> solution is added to form the CdS quantum dots encapsulated by dendrimers; finally, an X<2> solution, an M<2+> solution and an X<2-> solution are added thereto sequentially for obtaining CdS / MX core-shell quantum dots by dialysis. The reagent has advantages of high sensitivity, good selectivity and long retention time, the reagent itself and the solvent are harmless to human bodies, the method is simple and easy, sizes of the quantum dots are controllable, the quantum dots with core shell structures can enhance the fluorescence intensity and extend the service life of the quantum dots, and the fingerprint developing effect is slightly influenced when fingerprints are old. The reagent has wide range of applicability.

Description

technical field [0001] The invention relates to a preparation method of a rapid latent fingerprint display reagent, which belongs to the technical field of chemical detection. Background technique [0002] Human fingerprints have the characteristics of being different, unchanged throughout life, neat and orderly lines, and leaving marks on objects touched. Therefore, fingerprints have become the most reliable basis for identifying a person. However, in all kinds of crimes, criminals use more and more insidious and hidden means of committing crimes. Fingerprints that appear at crime scenes are often latent, and their ridge structure cannot be directly observed, so some means must be used to make them visible. [0003] In 1877, French doctor Aubert applied silver nitrate solution on paper to show sweat fingerprints while studying skin diseases and gland secretion, becoming the first person to create fingerprint display method. Since Aubert discovered the silver nitrate visu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N1/00G01N21/84G01N21/64A61B5/117
Inventor 罗运军李国平靳玉娟李杰卢文婷丛日敏
Owner BEIJING INSTITUTE OF TECHNOLOGYGY