Gold Nanostars in Plasmonic Photothermal Therapy: The Role of Tip Heads in the Thermoplasmonic Landscape

Throughout the history of science, comparison among calculated parameters and experimental observables has been considered as obvious to accomplish and reciprocate a fundamental hypothesis. The exploitation of sharp edges toward a plethora of paraphernalia has been continued from the prehistoric evidence to modern nanotechnology. To validate the hypotheses of the sharp edges, gold nanostars that exhibit their localized surface plasmon resonances in the visible-near-infrared region and contain multiple sharp tips have been considered as the model structures. Efficient control on the length and sharpness of the spikes has been achieved by judicious manipulation of the respective synthetic protocol. The electromagnetic simulation considering the topological parameters demonstrates an exotic interplay between the depolarization factor (P-z) and aspect ratio (alpha) to express the strength of the electric field generated at the tip heads as a function of their sharpness. Subsequent profiling of photothermal response caused by resistive heat exhibits an outstanding proof-of-concept resemblance between the local thermal manipulation and replicated in vitro laboratory experiment. Thus, the present work investigates an interdisciplinary analytical landscape enumerating the role of sharpness on the enhanced field and the temperature distribution localized at the tip head in the realm of plasmonic photothermal therapy.