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.