Chitosan-based micropowders for the development of latent fingermarks – the effect of biopolymer concentration on powder properties

Abstract

Detection and enhancement of these marks nowadays is of a huge importance for law enforcement agencies in order to identify persons/offenders. Although commercial chemical and physical methods provide satisfying results on multiple surfaces (glass, wood, rubber surface, etc.), many surfaces still pose a great challenge (firearms, colored surfaces and fabrics, etc.), and not to mention their toxicity and detrimental effect to users. Thus, many research groups focus their efforts in constant improvement and development of already used methods and in preparation of new systems. Due to their specific properties, the polymeric materials, especially biopolymers, are drawing an incredible level of the attention, while experiencing the rapid growth in all areas of research and application. However, the application of these materials in the field of forensic science has not yet been sufficiently exploited and the scientific public is almost unaware of its potential in aforementioned forensic application. In this paper, conjugates based on chitosan were obtained by the precipitating method. The initial concentration of the biopolymer (biopolymer/crosslinker ration) was varied and their potential in detection and visualization of latent fingermarks was examined. The prepared micropowders were characterized by spectrophotometric and spectroscopy methods, while scanning electron microscopy confirmed the shape, size and uniformity of the obtained micropowders, as well as their ability to bind to the fingerprint residues. The results demonstrated that these bio-based micropreparations have potential for commercial development and could complement commercial powders in visualizing and enhancing latent fingermarks.