title: Improvement in fingerprint detection using Tb(III)-dipicolinic acid complex doped nanobeads and time resolved imaging.
abstract: This paper deals with the synthesis and application of lanthanide complex doped nanobeads used as a luminescent fingerprint powder. Due to their special optical properties, namely a long emission lifetime, sharp emission profiles and large Stokes shifts, luminescent lanthanide complexes are useful for discriminating against signals from background emissions. This is a big advantage because latent fingerprints placed on multicoloured fluorescent surfaces are difficult to develop with conventional powders. The complex of 2,6-dipicolinic acid (DPA) and terbium ([Tb(DPA)3](3-)) is used for this purpose. Using the Stöber process, this complex is incorporated into a silica matrix forming nanosized beads (230-630nm). It is shown that the [Tb(DPA)3](3-) is successfully incorporated into the beads and that these beads exhibit the wanted optical properties of the complex. A phenyl functionalisation is applied to increase the lipophilicity of the beads and finally the beads are used to develop latent fingerprints. A device for time resolved imaging was built to improve the contrast between developed fingerprint and different background signals, whilst still detecting the long lasting luminescence of the complex. The developed fingerprint powder is therefore promising to develop fingerprints on multicoloured fluorescent surfaces.
authors.affiliation: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, Scotland; Department of Applied Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, Rheinbach, Germany.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Hauser
authors.affiliation: Department of Applied Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, Rheinbach, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Knupp
authors.affiliation: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, Scotland. Electronic address: s.officer@rgu.ac.uk.
authors.forename: Simon
authors.initials: S
authors.lastname: Officer
mesh_terms: D003878:Dermatoglyphics; D006801:Humans; D049449:Luminescence; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010848:Picolinic Acids; D017550:Spectroscopy, Fourier Transform Infrared; D013725:Terbium
chemical_list: D010848:Picolinic Acids; D013725:Terbium; C004860:dipicolinic acid
keywords: Fingerprint powder; Lanthanide luminescence; Silica-based nanobeads; Terbium(III) dipicolinic acid complex