Chitosan And Dextran Based Powders – The Preparation, Performance Comparison and Potential Application in Forensic Examination of Latent Fingermarks

Abstract

The papillary lines are unique for each person, and that feature is frequently used in modern forensic science to identify and distinguish individuals. Fingerprints are often present at the crime scene, but they are usually in the form of latent (invisible) marks which need to be visualized prior to the further processing. Many routinely employed commercial methods show harmful effect on human health, so the research groups are constantly trying to improve or develop some new approaches, and some of them are resorting to the utilization of bio(polymeric) materials. This paper deals with chitosan- and dextran-based biopowders prepared and characterized to evaluate their potential application in visualizing latent fingermarks. Chitosan and dextran are widely used in medicinal and pharmaceutical applications, but there are only a few studies regarding the utilization of these biopolymers as a component for the fingerprint powder. These biopolymeric materials offer many benefits, such as non-toxic properties, specific binding mechanisms, and they also satisfy the cost-benefit demands. Two chitosan-based formulations and one dextran-based formulation were obtained in simple synthesis processes. FT-IR analyses confirmed interactions between components of prepared systems. Optical microscopy showed that prepared powder formulations possess small and uniformly distributed particles, which contributed to their easy binding to the sweat and lipid residues present in the fingerprint trace. Prepared formulations were tested on a rubber (semi-porous) and glass (non-porous) surface. The results indicated that the obtained bio-based powders have the potential to complement commercially exploited physical systems/fingerprint powders in detecting and enhancing latent fingermarks.