[25a-P04-1~14] 12.7 Biomedical Engineering and Biochips

▲ [25a-P04-14] Simulation-Assisted Analysis and Design of Ellipse-faced Nanopillar Array
for LSPR Sensing

〇(P)Wilfred Espulgar^1,2, Masato Saito^1,2, Eiichi Tamiya^1,2 (1.AIST PhotoBIO-OIL, 2.Osaka Univ.)

Keywords:LSPR, Simulation, plasmonic substrate

LSPR is a very promising sensing technique for it provides a method that is label-free, fast in response, high stability, non-invasive, and real-time measurement. It has attracted wide attention in the field of biochemical sensing (e.g. proteins and mRNA) which detection mechanism solely relies on the refractive index variation of the surrounding medium of the nanostructures. Label-free and real-time analytical biosensing offered by this optical sensor can revolutionize environmental monitoring, disease prevention and mitigation, as well as healthcare and management. Moreover, LSPR biosensors offer several advantages in comparison to other sensors as it allows multiplexing capability, portability, low cost, and do not require relatively expensive proprietary instruments. But there is always a problem with sensitivity which should be balanced with reproducibility. And these are limited by the metallic nanostructures dimension and the fabrication method utilized. It has been well documented that the sensitivity of the LSPR substrate can be related to its resonant peak wavelength; a higher wavelength is expected to have better sensitivity. However, doing so will limit the detection range or will be hampered by the light acquisition setup. Optical detection may not be a problem but for imaging purposes, having a resonant peak beyond the visible range will not be compatible with most cameras. With this in mind, an LSPR substrate with multiple but distinct peaks is thought to be ideal that can be versatile to whatever detection system will be used and to the target analyte. After several tested geometries modeled in COMSOL Multiphysics, pillar structures with an ellipse base face were determined to be ideal for such a purpose. Future work of this study is to confirm the findings experimentally and optimize the model based on the actual shape of the nanopillars fabricated