Novel non-toxic and red luminescent sensor based on Eu³⁺:Y2Ti2O7/SiO2 nano-powder for latent fingerprint detection

Abstract Lanthanide doped inorganic nano-phosphor embedded into silica matrix have shown great potential in novel chemical and biological sensor development due to their pure, intense and stable photoluminescence (PL) properties. However, their potential applications in forensic science, especially in latent fingerprint detection in particular, were still unexplored. In this study, we have succeeded in production of high PL, photo-stable and non-toxic x mol% Eu3+:Y2Ti2O7 embedded into silica matrix powder (x mol% Eu3+/Y2Ti2O7 where x = 1.0, 2.0, 4.0 6.0, 10, 15 and 30) using sol-gel method followed by heat treatment. The crystal, morphological, optical and PL properties of the nano-phosphor powders were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopic (EDS), FT-IR and photoluminescence (PL) spectroscopy. Judd-Ofelt (J-O) theory was applied to a series of x mol% Eu3+:Y2Ti2O7 embedded into silica matrix based on their emission spectra. The results of in vivo toxicity test indicated that the prepared nano-phosphor embedded into silica matrix is non-toxic (LD50) for 15 mol% Eu3+ doped powder = 6.26 g/kg). The prepared nano-phosphor was successfully developing in latent fingerprint from various forensic relevant materials, including non-porous and porous surfaces.