Visualization of Latent Fingermarks by Nanotechnology: Reversed Development on Paper—A Remedy to the Variation in Sweat Composition

Abstract

Preis ohne Schweiß: „Negative“ von Fingerabdrücken lassen sich auf Papier mithilfe von Goldnanopartikeln (Kreise) mit einem difunktionellen Liganden und anschließende Silberabscheidung gewinnen. Dabei ist das Papier das Substrat und der Fingerabdruck die Maske. Die Unterschiede in der Schweißzusammensetzung individueller Personen spielen keine Rolle, sodass dieser Ansatz zur Entdeckung latenter Fingerabdrücke für Behörden nützlich sein könnte.

Trends in fingerprint analysis

“…The solution causes the precipitation of black silver which collects on the surface covered with AuNPs, resulting in a colorless print with a colored background. The sebaceous content of the fingerprint prevents the binding of the AuNPs and, therefore, prevents the coloring of the print with black silver [39]. This method does not work with all fingerprints, however, the process is still being optimized.…”

“…Previous methods [48,37,38] have proven to be inconsistent and unreliable on paper surfaces with poor contrast, so a new method using AuNP-cellulose interactions is being studied. For the development of this method, a bifunctional compound that would bind both cellulose and the AuNPs was used to attach the AuNPs to the paper followed by an Ag-PD solution that was then added to the surface [39]. The solution causes the precipitation of black silver which collects on the surface covered with AuNPs, resulting in a colorless print with a colored background.…”

Advances in the development and component recognition of latent fingerprints

“…Since then, a great deal of effort has been devoted to reducing the labor-intensity of this procedure [37][38][39]. Recently, MMD has been performed in a reverse manner by developing a paper substrate rather than fingerprint residue [40,41]. A review of applications to nanomaterials in LFPs' development was recently published [13].…”

Microscopic examination of fingermark residues: Opportunities for fundamental studies

“…But, despite the numerous available options and current endeavours to find increasingly more effective methods, a general lack of sensitivity and specificity has been noted. According to Jaber et al, 50% of the available marks remain undetected on porous substrates [6]. Despite significant ongoing research, it seems that the field has reached its detection threshold; no major realistic advances or ground-breaking discoveries have been made these past few years.…”