Applications for data security and latent fingerprint visualization using blue-emitting surface-modified LZO:Ce3+ nanophosphor

Abstract

The development of technology related to forensic is still beneficial and requires for continued research and the implementation of evaluation procedures. In this context, the current work focuses on the production of blue light emitting La2Zr2O7 nanophosphors (LZO) (NPs) doped with Ce3+ ions and surface modified with oleyl amine (OA) are employed for data security and latent fingerprint imaging applications. The formation of the pure pyrochlore phase is confirmed from powder X-ray diffraction (PXRD). The structural analysis is performed from Rietveld refinement . Scanning electron microscope (SEM) and transmission electron microscopy are used to study the surface morphology and crystallite size estimation respectively. Photoluminescence (PL) emission spectra exhibit all the characteristic emission peaks of Ce3+ ions. The surface modified NPs by OA exhibited 2-fold enhancement in the emission intensity as compared to unmodified NPs, which is due to effective intramolecular energy transfers from coordinated ligands to the activated Ce3+ ions, called the antenna effect. The most trustworthy proof of a person's identity can be found in the ridge characteristics revealed by the observed latent fingerprints employing surface modified nanophosphor. The chemical bonding between the nanophosphor and chemical components contained in the fingerprints, which enables the majority of authenticated sweat pores, further confirmed by high resolution photographs of formed latent fingerprints. The NPs which have OA grafted onto them can be made into security ink that can be used to create hidden inscriptions with a basic brush technique as well as screen print and decoded under 283 nm light illumination. The features of the NPs, which is a real-time option for latent fingerprint formation and anti-counterfeiting technologies are significantly improved by the surface modification technique .