Banana-Slice-Shaped Platinum-Based Nanosheets with Dual Phototherapeutic Functions for NIR Photothermal Tumor Therapy

Controllable synthesis of two-dimensional (2D) platinum (Pt)-based nanomaterials with high photothermal conversion property for near-infrared (NIR) photothermal tumor therapy (PTT) is highly desired yet challenging. Herein, we report iodide (I–)-engineered Pt-antimony nanosheets (PtSbI NSs) with an ultrathin banana-slice-shaped profile for PTT. These PtSbI NSs exhibit dual phototherapeutic functions including outstanding photothermal conversion efficiency (49.6%) versus PtSbI nanoparticles (24.2%), PtSb NSs (29.0%), and commercial Au NSs (10.7%) as well as excellent photothermal stability. When functionalized with aptamers targeting the tumor biomarker EpCAM, they can serve as a tumor-targeted nanozyme. Through reactive oxygen species generation, they effectively mitigate tumor hypoxia, induce selective tumor cell apoptosis, and facilitate synergistic photothermal–catalytic therapy, leading to an 83.3% reduction in tumor weight and a significant extension of survival in 4T1 breast cancer-bearing mice. This work is of great significance for advancing the synthesis and functionalization of 2D Pt-based nanomaterials employed in the PTT field and beyond.