On thermoplasmonic properties of star-shaped gold dimer nanoframes

Star-shaped Gold Dimer Nanoframes (SGDNs) with five branches have demonstrated exceptional thermoplasmonic potential for cancer photothermal therapy, leveraging their unique plasmonic properties. This study focuses on the critical role of nanoframe width in modulating local electric fields and enhancing surface temperatures. The results indicate that increasing the width of SGDNs induces a blue shift in the first plasmon mode and decreases the absorption peak intensity. In contrast, the second mode shows an increase in electric field enhancement with width. Maximum hotspots (E/E₀)_max = 250 were observed in the central gap for the second mode, with associated temperature increases reaching ΔT_max ≈ 30 °C in skin-like environments, significantly higher than the first mode (ΔT_max = 12 °C). These temperature enhancements, particularly localized at inter-arm gaps, underline SGDNs' effectiveness in targeted thermal applications, selectively destroying tumor cells while preserving surrounding healthy tissues. The study provides clear evidence supporting SGDNs as highly efficient nanostructures for photothermal cancer treatment in VIS and NIR regions.