Intercalation‐Activated Layered MoO₃ Nanobelts as Biodegradable Nanozymes for Tumor‐Specific Photo‐Enhanced Catalytic Therapy

Abstract The existence of natural van der Waals gaps in layered materials allows them to be easily intercalated with varying guest species, offering an appealing strategy to optimize their physicochemical properties and application performance. Herein, we report the activation of layered MoO 3 nanobelts via aqueous intercalation as an efficient biodegradable nanozyme for tumor‐specific photo‐enhanced catalytic therapy. The long MoO 3 nanobelts are grinded and then intercalated with Na + and H 2 O to obtain the short Na + /H 2 O co‐intercalated MoO 3− x (NH−MoO 3− x ) nanobelts. In contrast to the inert MoO 3 nanobelts, the NH−MoO 3− x nanobelts exhibit excellent enzyme‐mimicking catalytic activity for generation of reactive oxygen species, which can be further enhanced by the photothermal effect under a 1064 nm laser irradiation. Thus, after bovine serum albumin modification, the NH−MoO 3− x nanobelts can efficiently kill cancer cells in vitro and eliminate tumors in vivo facilitating with 1064 nm laser irradiation.