Rationally designed dual-plasmonic gold nanorod@cuprous selenide hybrid heterostructures by regioselective overgrowth for in vivo photothermal tumor ablation in the second near-infrared biowindow

NIR-II plasmonic materials offer multiple functionalities for biomedical applications, such as photothermal tumor ablation, surface-enhanced Raman scattering biosensing, photoacoustic imaging, and drug carriers. However, integration of noble metals and plasmonic semiconductors is greatly challenging because of the large lattice-mismatch. This study reports the regioselective overgrowth of Cu Se on gold nanorods (GNRs) for preparation of dual-plasmonic GNR@Cu Se hybrid heterostructures with tunable NIR-II plasmon resonance absorption for photothermal tumor ablation. The regioselective deposition of amorphous Se and its subsequent conversion into Cu Se on the GNRs are performed by altering capping agents to produce the GNR@Cu Se heterostructures of various morphologies. Their photothermal performances for NIR-II photothermal tumor ablation are evaluated both and . We find that the lateral one- and two-side deposition, conformal core-shell coating and island growth of Cu Se on the GNRs can be achieved using different capping agents. The Cu Se domain size in these hybrids can be effectively adjusted by the SeO concentration, thereby tuning the NIR-II plasmon bands. A photothermal conversion efficiency up to 58-85% and superior photostability of these dual-plasmonic hybrids can be achieved under the NIR-II laser. Results also show that the photothermal conversion efficiency is dependent on the proportion of optical absorption converted into heat; however, the temperature rise is tightly related to the concentration of their constituents. The excellent NIR-II photothermal effect is further verified in the following and experiments. This study achieves one-side or two-side deposition, conformal core-shell coating, and island deposition of Cu Se on GNRs for GNR@Cu Se heterostructures with NIR-II plasmonic absorption, and further demonstrates their excellent NIR-II photothermal tumor ablation . This study provides a promising strategy for the rational design of NIR-II dual-plasmonic heterostructures and highlights their therapeutic potential.