Photothermal\nProperties of Solid-Supported Gold Nanorods

Gold nanoparticles\npossess unique photothermal properties\nand have\ngained considerable interest in biomedical research, particularly\nfor photothermal therapy (PTT). This study focuses on evaluating the\nphotothermal properties of gold nanorods (AuNRs) supported on glass\nsubstrates upon excitation with near-infrared (NIR) light. Two aspect\nratios of AuNRs were electrostatically immobilized onto glass with\ncontrolled coverage. <i>In situ</i> X-ray diffraction (XRD)\nwas performed to evaluate the photothermal behavior and morphological\nchanges of the supported AuNRs during NIR laser irradiation. The XRD\ndata sets were corroborated with scanning electron microscopy and\nVis-NIR spectroscopy characterization. XRD revealed a linear temperature\nincrease with laser power, aligning with theoretical predictions,\nand a slope dependent on the AuNR coverage, until the onset of morphology\ntransformations around 120 °C. This study provides valuable insights\ninto the photothermal properties of supported AuNRs, crucial for their\napplication in PTT.