Visualization and dermatoglyphics of latent fingerprints (sweat pores): Security ink for anticounterfeiting labels and case studies

Abstract

In this report, 1,8-naphthalimide (NG)-based blue emitters non-covalently doped on silica was used for visualization of latent fingerprints and anticounterfeiting applications. The NG possess CIE coordinate value x = 0.2, y = 0.32 with blue-green emission in solid state and possess low cytotoxicity with IC50 value 85 µM. The excellent performance of NG@SiO2 was demonstrated by visualization of LFPs up to levels 1–3 on a variety of substrates including porous and nonporous surfaces using powder dusting method without any post treatment. The details of level 1 (classification); level 2 (19 minutiae points such as bifurcations, hook, eye, delta, bridge, crossover, lake, island, ridge incipient, scar and speciality features) and level 3 (size, shape, number and position of sweat pores, width of the fingerprint ridge) are clear. A detailed case studies have been carried out by collecting fingerprints from 14 subjects aged between 19 and 29 years. Each collected LFPs were screened and differentiated from each other to establish the individuality of subjects using information of levels 1–3, The NG was further used for developing invisible security ink for use in pen, stamp pad for writing/stamping on paper and silica-coated TLC plates. These results may find applications in forensic science and data security.