Spectral Manipulation of X-Ray Excited Optical/Persistent Luminescence by Constructing Metal-Organic Framework@Fluoride Nanoparticles Composites

Lanthanide doped fluoride nanoparticles (NPs) possess superior X-ray excited optical luminescence (XEOL) and persistent luminescence (XEPL), which attracts great attention in many fields. Manipulating profiles of XEOL and XEPL spectra is of siginificance for new emerging applications, however, the intrinsic sharp 4f-4f transitions of trivalent lanthanide ions only generate narrow emission profiles. Here, a convenient and versatile strategy is demonstrated to greatly modulate the emission spectrum in a broad wavelength range by constructing a new class of metal-organic framework (MOF)@NPs composites which involves electrostatic binding of positively charged various rare-earth containing fluoride nanoparticles with the same negatively charged surface of a MOF. The emission profile can be facile designed through controlling the attached NPs composition and their relative contents on the MOF crystals. For the first time, the MOF@NPs composites are employed to realize full XEOL spectrum for multiple organic molecules sensing using the matching of their absorption profiles with the XEOL of a specific NP to effect energy transfer. In addition, time and temperature dependent multicolor XEPL evolution provides advanced information encryption. These findings can promote the exploration of a new type of nanoscintillators with innovative XEOL and XEPL performances.