Development of a large-area plasmonic sensor substrate with dielectric subwavelength gratings using nanoimprint...

We demonstrated an enhanced surface plasmon resonance (SPR) detection by incorporating subwavelength SiO2 gratings built on a thin silver film. Large-area SiO2 gratings were fabricated by nanoimprint lithographic technique and dry etching processes and used to sense a surface-limited biomolecular interaction. Numerical results based on rigorous coupled-wave analysis method exhibited that the dielectric gratings can provide a notable sensitivity improvement by 2 times, which is attributed to an increase in surface reaction area. As another possible application of the fabricated plasmonic substrate, experimental data of imaging the cell morphology were also presented. This study was intended to show the feasibility and extend the applicability of a large-area grating-based SPR substrate to diverse optical bioengineering fields.