Versatile fluorescent Gd2MoO6:Eu3+ nanophosphor for latent fingerprints and anti-counterfeiting applications

At present, latent fingerprint and anti-counterfeit detection technologies have become key factors in forensic science. Here, we report on the synthesis and characterizations of Eu3+ ions doped monoclinic Gd2MoO6 nanophosphors for latent fingerprints and anti-counterfeiting applications. The crystalline structure, phase purity and lattice parameters of Gd2MoO6:Eu3+ nanophosphors were investigated in detail using the X-ray diffraction and Rietveld refinement analyses. The photoluminescence excitation spectra of Gd2MoO6:Eu3+ nanophosphor unveiled their strong charge transfer band and characteristic f-f transitions of Eu3+ ions in the UV and near-UV regions. Whereas, the corresponding emission spectra showed an intense red emitting hypersensitive transition (D-5(0)-> F-7(2)) with excellent CIE coordinates (0.6503, 0.3490). The concentration quenching of Eu3+ ions in Gd2MoO6 host lattice was observed at 5 mol%. The optimized Gd2MoO6:Eu3+ nanophosphor was used to detect the latent fingerprints and anti-counterfeits. The developed latent fingerprints fluorescent images enabled three levels of identifications with high contrast, selectivity and sensitivity. Also anti-counterfeit marker was successfully developed through handwriting and spray method. The obtained results of the synthesized Gd2MoO6:Eu3+ nanophosphors signifying their potential use in latent fingerprint and anti-counterfeit applications.