title: Fingerprint visualization enhancement by deposition of columnar thin films and fluorescent dye treatment.
abstract: Enhanced visualization of latent fingerprints on two non-porous surfaces, smooth glass slides and highly reflecting rough aluminum sheets, is obtained by depositing columnar thin films (CTFs) of calcium fluoride (CaF2) and silica (SiO2) by physical vapor deposition at large oblique angles. Due to the vapor flux getting shadowed by the physical residues in the fingerprints, the CTFs are deposited only on the upraised ridges, resulting in highly enhancing the visibility of the fingerprint. The visualization of these fingerprints with deposited CTFs is further enhanced by subsequently treating them with a fluorescent dye and fluorescence imaging. A specific amino-acid reagent (1,2-indanedione) and non-specific laser dye (Rhodamine 6G), both allowed enhanced visualization of the CTFs grown on the fingerprints, due to the localization and entrenchment of the dye within the CTF regions.
authors.affiliation: Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India. jhuma@iitk.ac.in
authors.forename: Jhuma
authors.initials: J
authors.lastname: Dutta
authors.forename: S A
authors.initials: SA
authors.lastname: Ramakrishna
authors.forename: I
authors.initials: I
authors.lastname: Mekkaoui Alaoui
mesh_terms: D002124:Calcium Fluoride; D003878:Dermatoglyphics; D005456:Fluorescent Dyes; D006801:Humans; D007189:Indans; D008853:Microscopy; D049329:Nanostructures; D012235:Rhodamines; D012822:Silicon Dioxide; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014835:Volatilization
chemical_list: C413384:1,2-indanedione; D005456:Fluorescent Dyes; D007189:Indans; D012235:Rhodamines; C026188:rhodamine 6G; D012822:Silicon Dioxide; D002124:Calcium Fluoride