A strategy for the enhanced development of latent fingermarks with minimally destructive to DNA based on fluorescence Eu-Tb metal–organic framework

Abstract

Fingermarks identification have always been the most effective and reliable way for individuals determination among the forensic science. The fingermarks at the scene of the case as the valuable physical evidence to analyze the trajectory of criminal behavior and portray the characteristics of the suspect play an irreplaceable role in the process of investigation. To reach its pivotal biometric individualization, the luminescent metal–organic framework (Eu@Tb-LL) was prepared via a simple optimized solvothermal method for visualizing the latent fingermarks with minimally destructive to DNA in this work. Eu@Tb-LL exhibited ideal optical stability and fluorescence intensity at the wavelength of 530 and 620 nm during revealing latent fingermarks. Meanwhile, Eu@Tb-LL is more effective than indandione (commonly used in the site investigation) in revealing aged fingermarks. More significantly, the Eu@Tb-LL superimposed on commercial manifestation reagents (Hfb) enhanced the effect of Hfb for revealing blood latent fingermarks on the non-porous objects. In addition, the STR testing results performed after the visualization process proved the Eu@Tb-LL was minimally destructive to DNA with a confidence interval of 95 %, exhibiting promising prospects for practical criminal investigation applications.