Fingerprints are unique and life-long to everyone, so they occupy very important statuses in forensic science. However, due to the limit of current imaging technologies and instruments, recognition and matching of fin...Fingerprints are unique and life-long to everyone, so they occupy very important statuses in forensic science. However, due to the limit of current imaging technologies and instruments, recognition and matching of fingerprints are mostly based on their level 2 structures（bifurcation, crossover, and etc.）.Moreover, in real-world cases, fingerprints collected in the field are often incomplete or damaged, which adds further difficulty in fingerprint analysis. Quantum dots（QDs） are superior fluorescent imaging agents for latent fingerprints, which can provide both level 2 and level 3（sweat pores） details. Here, we used red-emitting N-acetylcysteine-capped Cd Te QDs as imaging agent for staining of eccrine LFPs. The numbers of level 2 and level 3 features that can be mapped are significantly larger than those obtained by cyanoacrylate fuming, a standard technique being adopted at forensic scene. Therefore, the level 2 and level 3 characteristics from QD-staining were simultaneously extracted for improved fingerprint analysis.A preliminary fingerprint matching based modified Pore Matching algorithm was thus developed based on the integration of both level 2 and level 3 characteristics. Satisfactory results of fingerprint matching were obtained, demonstrating the advantage of the QD-staining for advanced fingerprint analysis.展开更多
A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The...A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The silica-coated Fe3O4NPs were functionalized with amino groups by(3-aminopropyl)triethoxysilane to provide Fe3O4@SiO2-NH2NPs,which was then chemically conjugated with GSH-modified CdTe QDs to form bifunctional magnetic-fluorescent NPs,Fe3O4@SiO2-NH-CO-CdTe-QDs NPs.The properties and morphologies of Fe3O4@SiO2-NH-CO-CdTe-QDs NPs were investigated by FTIR,X-ray diffraction,transmission electron microscopy(TEM),absorption and fluorescence spectroscopy and vibrating sample magnetometry.TEM images display that Fe3O4@SiO2-NH-CO-CdTe-QDsNPs possess spherical core-shell structure with a uniform size about 50 nm.The bifunctional NPs were found to exhibit good magnetic and strong fluorescent properties favorable for their application in the detection of latent fingerprints.Furthermore,the carboxyls on the surface of NPs have good absorptions with water in air and the residues of fingerprints so as to not only avoid dust flying to protect the health of operators,but also improve the efficiency of detection.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21475090 and 21522505)
文摘Fingerprints are unique and life-long to everyone, so they occupy very important statuses in forensic science. However, due to the limit of current imaging technologies and instruments, recognition and matching of fingerprints are mostly based on their level 2 structures（bifurcation, crossover, and etc.）.Moreover, in real-world cases, fingerprints collected in the field are often incomplete or damaged, which adds further difficulty in fingerprint analysis. Quantum dots（QDs） are superior fluorescent imaging agents for latent fingerprints, which can provide both level 2 and level 3（sweat pores） details. Here, we used red-emitting N-acetylcysteine-capped Cd Te QDs as imaging agent for staining of eccrine LFPs. The numbers of level 2 and level 3 features that can be mapped are significantly larger than those obtained by cyanoacrylate fuming, a standard technique being adopted at forensic scene. Therefore, the level 2 and level 3 characteristics from QD-staining were simultaneously extracted for improved fingerprint analysis.A preliminary fingerprint matching based modified Pore Matching algorithm was thus developed based on the integration of both level 2 and level 3 characteristics. Satisfactory results of fingerprint matching were obtained, demonstrating the advantage of the QD-staining for advanced fingerprint analysis.
基金supported by National Key Research and Development Program of China(213 project)National Basic Research Program of China(2015CB931900)+4 种基金National Science Foundation for Distinguished Young Scholars(51825304)the National Natural Science Foundation of China(21632009,21674124,21704110)Strategic Priority Research Program of Chinese Academy of Sciences(XDB20000000)Shanghai Scientific and Technological Innovation Project(16DZ1205600,16JC1402500,17DZ1205401,17DZ1205402,18JC1410600,18JC1415500,18ZR1448600)Opening Project of Shanghai Key Laboratory of Crime Scene Evidence(2017XCWZK24,2015XCWZK15)
文摘A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The silica-coated Fe3O4NPs were functionalized with amino groups by(3-aminopropyl)triethoxysilane to provide Fe3O4@SiO2-NH2NPs,which was then chemically conjugated with GSH-modified CdTe QDs to form bifunctional magnetic-fluorescent NPs,Fe3O4@SiO2-NH-CO-CdTe-QDs NPs.The properties and morphologies of Fe3O4@SiO2-NH-CO-CdTe-QDs NPs were investigated by FTIR,X-ray diffraction,transmission electron microscopy(TEM),absorption and fluorescence spectroscopy and vibrating sample magnetometry.TEM images display that Fe3O4@SiO2-NH-CO-CdTe-QDsNPs possess spherical core-shell structure with a uniform size about 50 nm.The bifunctional NPs were found to exhibit good magnetic and strong fluorescent properties favorable for their application in the detection of latent fingerprints.Furthermore,the carboxyls on the surface of NPs have good absorptions with water in air and the residues of fingerprints so as to not only avoid dust flying to protect the health of operators,but also improve the efficiency of detection.
