ABSTRACT
From the point of view of classical electrodynamics, nano-optical and enantioselective tweezers for single biomolecules have been routinely investigated using achiral and chiral localized surface plasmons, respectively. In this work, we propose the use of interference of collective plasmons (Fano-type plasmon) that exist in densely hexagonal plasmonic oligomers to design a high-efficiency nano-optical tweezer to trap individual biomolecules with a radius of 2 nm. For this purpose, we fabricated and simulated 2D hexagonal arrays of Au nanoparticles (AuNPs) with sub-wavelength lattice spacing which support collective plasmons by near-field coupling. Our full-field simulations show that densely hexagonal plasmonic oligomers can enhance the Fano-like resonances arising from the interference of superradiant and subradiant modes. This interference of collective plasmons results in a strong intensification and localization of the electric near-field in the interstice of the AuNPs. The methodology can also be extended to collective chiral near-fields for all-optical enantioseparation of chiral biomolecules with a small chirality parameter (±0.001) with the hypothesis of the existence of strong magnetic near-fields.
ABSTRACT
Advances in nanobiotechnology have allowed the utilization of nanotechnology through nanovaccines. Nanovaccines are powerful tools for enhancing the immunogenicity of a specific antigen and exhibit advantages over other adjuvant approaches, with features such as expanded stability, prolonged release, decreased immunotoxicity, and immunogenic selectivity. We introduce recent advances in carbon nanotubes (CNTs) to induce either a carrier effect as a nanoplatform or an immunostimulatory effect. Several studies of CNT-based nanovaccines revealed that due to the ability of CNTs to carry immunogenic molecules, they can act as nonclassical vaccines, a quality not possessed by vaccines with traditional formulations. Therefore, adapting and modifying the physicochemical properties of CNTs for use in vaccines may additionally enhance their efficacy in inducing a T cell-based immune response. Accordingly, the purpose of this study is to renew and awaken interest in and knowledge of the safe use of CNTs as adjuvants and carriers in vaccines.
