Dumbbell-Shaped Gold Nanorod@Mesoporous Palladium Nanozymes for NIR-II-Triggered Photocatalytic Amplification and Trimodal Cancer Therapy

While nanozyme-mediated catalytic therapy holds promise for precision oncology, achieving spatiotemporal control over enzymatic activity and synergistic therapeutic amplification in the biologically favorable second near-infrared window (NIR-II) remains an unmet challenge. In this study, we present a breakthrough in plasmonic heterojunction engineering through the rational design of asymmetric dumbbell-shaped Au nanorod@end-mesoporous Pd architectures that establish a high density of plasmonic hotspots at the mesopore sites. Unlike conventional core-shell configurations (Au@mesoPd) showing negligible NIR-II response, our heterostructure demonstrates a nearly 200% enhancement in peroxidase-like activity under 1064 nm excitation through precisely engineered hot electron dynamics. Time-resolved absorption spectroscopy and COMSOL simulations reveal that the unique terminal deposition of mesoporous Pd domains creates high-density electromagnetic hotspots (>200% field enhancement vs core-shell) while maintaining efficient charge transfer channels─synergistically boosting both hot carrier generation and catalytic turnover frequency. This nanoarchitecture integrates NIR-II photoacoustic navigation with a triple therapeutic modality, combining plasmon-enhanced photothermal ablation, Pd-mediated catalytic therapy, and chemotherapy, which holds great potential for NIR-II-triggered synergistic multimodal cancer therapy.