Studies into exfoliation and coating of Egyptian blue in methanol for application to the detection of latent fingermarks.

[Display omitted] • A very much simpler exfoliation method for Egyptian blue pigment was introduced. • In a comprehensive study commercial particles and exfoliated ones were compared for fingermark detection. • Coated exfoliated particles outperformed commercial particles for aged marks on non-porous surfaces. • Tween 20-coated exfoliated particles demonstrated highest contrast on challenging substrates. We have recently demonstrated that coated exfoliated Egyptian blue powder is effective for detecting latent fingermarks on a range of highly-patterned non-porous and semi-porous surfaces. In this extension of that work, we present our studies into an alternative approach to prepare exfoliated Egyptian blue coated with cetrimonium bromide and Tween® 20 using a simpler technique. The quality of the latent fingermarks developed with these exfoliated powders and the commercial powder were compared in a comprehensive study. Depletion series of natural fingermarks from a wide range of donors (12 males and females) deposited on non-porous (glass slides) and semi-porous (Australian banknotes) surfaces were used in this study. Enhancement in the performance of the coated exfoliated particles compared to the commercial powder was observed, particularly in the case of aged fingermarks and polymer banknotes as challenging substrates. [ABSTRACT FROM AUTHOR]