Super-Resolution by Localized Plasmonic Structured Illumination Microscopy Using Self-Assembled Nanoparticle Substrates

Abstract

Structured illumination microscopy (SIM), an advanced super-resolution methodology, transcends the traditional diffraction limit inherent in optical imaging. This technique utilizes standing-wave illumination generated through the interplay of two obliquely incident light waves. The intrinsic resolution constraint of SIM, traditionally pegged at half the wavelength because of the standing wave’s periodicity, has the potential for enhancement by integrating high spatial frequency illumination patterns, particularly when sourced in the near-field of plasmonic nanostructures. The present study introduces and computationally validates a novel, easily fabricated substrate composed of self-assembled gold nanoparticles designed explicitly for generating these high spatial frequency patterns. Addressing the necessity for diverse patterns in reconstructing super-resolution imagery within plasmonic SIM, this research conducted extensive numerical simulations of nanoparticle arrays under varying illumination scenarios. This undertaking affirmed the feasibility of manipulating high-frequency patterns. Super-resolution reconstruction was actualized by applying Blind-SIM techniques, which verified its effectiveness. This innovative approach notably achieved a resolution threshold of 60 nm, markedly exceeding the conventional 150 nm diffraction barrier and surpassing the 75 nm resolution typically observed in standard SIM applications.