Gold Suprashells: Enhanced Photothermal Nanoheaters with Multiple Localized Surface Plasmon Resonances for Broadband Surface-Enhanced Raman Scattering
journal contributionposted on 08.03.2017, 00:00 by Sureyya Paterson, Sebastian A. Thompson, Alastair W. Wark, Roberto de la Rica
In this paper, we report on a new type of self-assembled plasmonic nanostructure, called gold suprashells, which are assembled around superparamagnetic iron oxide nanoparticle (SPION) cores. Gold suprashells have multiple surface plasmon resonances over a broad vis–NIR wavelength range, which makes them useful in applications where broadband absorption is required. For example, suprashells are efficient substrates that enhance surface-enhanced Raman scattering signals across multiple excitation wavelengths. This unique multiresonant character is afforded by the suprashell structure, which comprises anisotropic assemblies of nanoparticles of tunable length. Furthermore, gold suprashells generate more heat when excited with a laser compared to the nanoparticle building blocks, therefore making them promising materials for photothermal applications. The suprashells can potentially be assembled onto any negatively charged core, which opens up multiple possibilities for the development of multifunctional core/suprashell nanoparticle designs. Here, we assemble gold suprashells around dextran-coated SPIONs in order to obtain plasmonic and magnetic nanoparticles. Cells that have internalized the multifunctional nanoparticles can be accumulated with a magnet and killed with a laser through the generation of plasmonic heat. This approach shows promise for the development of therapies aimed at killing circulating tumor cells by utilizing the proposed magnetic and plasmonic nanoparticles.