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

Abstract

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 ∼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.