Preparation of Dye Molecule-Intercalated MoO<inf>3</inf> Organic/Inorganic Superlattice Nanoparticles for Fluorescence Imaging-Guided Catalytic Therapy

Abstract

Intercalation of organic molecules into the van der Waals gaps of layered materials allows for the preparation of organic/inorganic superlattices for varying promising applications. Herein, the preparation of a series of dye molecule/MoO3 organic/inorganic superlattice nanoparticles by aqueous intercalation of several dye molecules into layered MoO3 for fluorescence imaging-guided catalytic therapy is reported. The long MoO3 nanobelts are treated by ball milling and subsequent aqueous intercalation followed by a cation ion exchange to obtain the dye molecule-intercalated MoO3 organic/inorganic superlattices. Importantly, because of the activation induced by organic intercalation, the Nile blue (NB)-intercalated MoO3-x (NB-MoO3-x) nanoparticles show excellent catalytic activity for the generation of reactive oxygen species, that is, hydroxyl radical (·OH) and superoxide anion (·O2−), through catalyzing H2O2 and O2, respectively. Moreover, the intense fluorescence of the intercalated NB molecules endows NB-MoO3-x with the in vivo fluorescence imaging capability. Thus, the polyvinylpyrrolidone-modified NB-MoO3-x nanoparticles can be used for tumor-specific catalytic therapy to realize efficient cancer cell elimination in vitro and fluorescence imaging-guided tumor ablation in vivo.