Dye-Encapsulated Lanthanide Metal–Organic Framework-Based Photonic Crystals for Multilevel Optical Anticounterfeiting Application

Chemical fluorescence-based photonic structures as multilevel optical anticounterfeiting materials have attracted increasing attention for extended and enhanced properties, yet the construction of fluorescent metal–organic framework (MOF)-embedded photonic crystals is still in infancy. Here, a multilevel anticounterfeiting platform was designed and constructed by a combination of photonic crystals with a photofunctionalized lanthanide MOF. Fluorescent dye was encapsulated into an MOF to produce a series of excitation-dependent fluorescent materials, which were further dispersed into a photonic crystal matrix with structural color; thus, a multilevel anticounterfeiting material with excitation-dependent fluorescent and angle-dependent structural color was realized. Such a strategy significantly improves anticounterfeiting security. This work provides a perspective for the development of multilevel optical anticounterfeiting technology based on a synergy of fluorescent and structural colors.