Nanoarrow-Derived Open-Channel Nanoframes Capable of Colloidal Host-Guest Encapsulation

Metallic nanoframes exhibiting well-defined hollow structures have attracted considerable interest because of their unique interactions with matter and light. However, the synthesis of tubular nanoframes with walled structures and concave cavities has been rarely reported, and the use of nanoframes in colloidal encapsulation systems remains largely unexplored. Herein, we design and synthesize two types of unconventional PtAu tubular nanoframes derived from gold nanoarrows, namely, arrow-shaped nanoframes (ANFs) and open-channel nanoframes (ONFs). Remarkably, the ONFs exhibit a unique open-end hourglass-like structure containing a cross-shaped cavity, which endows them with a remarkable capability of colloidal encapsulation. Accordingly, we achieve dithiol-induced coassembly of the ONFs with nanospheres via dithiol linkage and shape-complementary coassembly of the ONFs with nanooctahedra driven by hydrophobic interaction. This work may offer new insights into the structural design of sophisticated nanoframes and provide opportunities to explore novel colloidal encapsulation systems.