Engineering a CeO₂ layer on gold nanopyramids for enhanced near-infrared photothermal conversion

Gold-based core-shell oxides show great potential in photothermal theranostics, but their applications are limited by the inability for precise regulation of light absorption. Here, we developed a type of gold bipyramid covered by a cerium oxide layer (ACH) with tunable thickness to enhance near-infrared light absorption and photothermal conversion efficiency. The anisotropic feature enabled ACH with strong light absorption at 1064 nm, accompanied by photothermal efficiency as high as 56.2%. In vitro and in vivo results demonstrated that ACH possessed capabilities for dual-modality molecular-targeted imaging and efficient tumor inhibition via photothermal therapy. Integration of the computed tomography and photoacoustic imaging capabilities of ACH nanoparticles showed real-time feedback during synergistic treatment, enabling timely monitoring and adjustment of therapeutic procedures. This work reveals the impact of metal oxide layer on the photothermal performance of plasmonic nanostructures, providing a new strategy for near-infrared theranostics.