EGCG assisted Y2O3:Eu3+ nanopowders with 3D micro-architecture assemblies useful for latent finger print recognition and anti-counterfeiting applications

In the present work, an intense red Y2O3:Eu3+ nanopowders (NPs) were synthesized by ultrasonication, hydrothermal and solution combustion methods. Structural and luminescence properties of obtained compounds were compared by using powder X-ray diffraction and photoluminescence (PL) studies respectively. Compounds obtained from ultrasonication method showed the smallest crystallite size of similar to 10 nm and increased PL intensity as compared to compounds obtained by other two methods. Optimized NPs obtained from ultrasonication method were further used as a labeling agent for the better visualization of latent finger prints (LFPs) on different porous and non-porous surfaces. Visualized LFPs exhibits high sensitivity, reproducibility, selectivity, reliability and can obtain the complete ridge details. LFPs of up to level 3 ridge details were explored (i.e., sweat pores) by staining optimized Y2O3:Eu3+ NPs by simple powder dusting method. SEM micrographs of the samples obtained from ultrasonication method showed flower like morphology with crystal-splitting based particles. Images obtained using Y2O3:Eu3+ based fluorescent ink showed high intense light under UV excitation and no clear image under normal light confirms its potential as anti-counterfeit ink. The property of high surface activity demonstrates that the prepared NPs are the promising luminescent materials for display devices, LFPs visualization and anti-counterfeiting applications. (C) 2018 Elsevier B.V. All rights reserved.