PUBLIC RELEASE DATE:

1-Oct-2014

Contact: Michael Bishop michael.bishop@iop.org 44-117-930-1032 Institute of Physics @PhysicsNews

A group of researchers from Switzerland has thrown light on the precise mechanisms responsible for the impressive ability of nanoparticles to detect fingermarks left at crime scenes.

Publishing their results today, 2 October, in IOP Publishing's journal Nanotechnology, the researchers have provided evidence contesting the commonly accepted theory that nanoparticles are attracted to fingermarks electrostatically.

The attraction, they claim, is in fact chemical and is caused by compounds on the surface of nanoparticles bonding with a complex cocktail of compounds present in fingermark residue.

The researchers believe a more fundamental understanding of the interactions between nanoparticles and fingermarks will promote the development of more precise targeting methods and increase the chances of detecting previously undetectable fingermarks.

Indeed, it has been estimated that around 50 per cent of the fingermarks left on paper remain undetected.

Lead author of the study Sebastien Moret said: "There are number of different techniques used to visualise fingermarks when they are brought into the lab; however, they all lack sensitivity."

"Some of these techniques show an affinity not only for fingermarks, but also for the substrate or surface that the mark was left on, leading to background staining that conceals the fingermark."

Originally posted here:

Nanoparticles give up forensic secrets