Synthesizing Ag(+): MgS, Ag(+): Nb(2)S(5), Sm(3+): Y(2)S(3), Sm(3+):Er(2)S(3), and Sm(3+):ZrS(2) Compound Nanoparticles for Multicolor Fluorescence Imaging of Biotissues

[Image: see text] Development of the fluorophores whose fluorescence bands can be flexibly selected is of great interest for biotissue imaging. Compounds of Ag(+):MgS, Ag(+):Nb(2)S(5), Sm(3+):Y(2)S(3), Sm(3+):Er(2)S(3), and Sm(3+):ZrS(2) were obtained through new chemical synthesis. They were characterized by X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. They revealed polychromatic-photoluminescence spectra when excited by 280, 380, 480, 580, 680, and 785 nm light. Especially, near-infrared emission ranging from 800–1100 nm was found upon 785 nm light excitation. A band model was proposed to explain transitions responsible for the observed components of emission. Their broad fluorescence spectra cover from the ultraviolet to near-infrared spectral range. Their ability of emitting wide-range fluorescence was utilized for multicolor fluorescence imaging of biotissues, as demonstrated by pig-kidney tissue samples.