A Magnetically Responsive Polydiacetylene Precursor for Latent Fingerprint Analysis

• Published in: ACS applied materials & interfaces Vol. 8; no. 9; pp. 6245 - 6251
• Main Authors: Lee, Joosub, Lee, Chan Woo, Kim, Jong-Man
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.03.2016
• Subjects: Acetylene - chemistry; Dermatoglyphics; Ferrosoferric Oxide - chemistry; Hydrophobic and Hydrophilic Interactions; Magnetics; Magnetite Nanoparticles - chemistry; Microscopy, Fluorescence; Polyacetylenes - chemistry; Polymers - chemistry; Ultraviolet Rays; magnetic nanoparticle; conjugated polymer; polydiacetylene; fingerprint analysis; latent fingerprint
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b00566

A magnetically responsive diacetylene (DA) powder was developed for the visualization of latent fingerprints. A mixture of the DA and magnetite nanoparticles, applied to a surface containing latent fingermarks, becomes immobilized along the ridge patterns of the fingerprints when a magnetic field is applied. Alignment along the ridge structures is a consequence of favorable hydrophobic interactions occurring between the long alkyl chains in the DAs and the lipid-rich, sebaceous latent fingermarks. UV irradiation of the DA–magnetite composite immobilized on the latent fingerprint results in the generation of blue-colored PDAs. Heat treatment of the blue-colored image promotes a blue-to-red transition as well as fluorescence turn-on. A combination of the aligned pale brown-colored monomeric state, UV irradiation generated blue-colored PDA state, as well as the heat treatment generated red-colored and fluorescent PDA state enables efficient visual imaging of a latent fingerprint, which is deposited on various colored solid surfaces.