Optimizing Electromagnetic Hotspots in Plasmonic Bowtie Nanoantennae

• Published in: The journal of physical chemistry letters Vol. 4; no. 3; pp. 496 - 501
• Main Authors: Dodson, Stephanie, Haggui, Mohamed, Bachelot, Renaud, Plain, Jérôme, Li, Shuzhou, Xiong, Qihua
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.02.2013
• Subjects: Engineering Sciences; Micro and nanotechnologies; Microelectronics; Optics; Physics; Plasmonics, Optical Materials, and Hard Matter; optical nanoantenna; discrete dipole approximation (DDA); plasmonics; localized surface plasmon resonance (LSPR); surface-enhanced raman spectroscopy (SERS)
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/jz302018x

Sensitivity is a key factor in the improvement of nanoparticle-based biosensors. Bowtie nanoantennae have shown high sensitivity for both surface-enhanced Raman scattering (SERS)- and localized surface plasmon resonance (LSPR)-based biosensing. In this work, optical bowtie nanoantennae with varying geometries were simulated, fabricated, and characterized. We successfully fabricated sub-5 nm gaps between prisms. The gap between prisms, the prism size, and the radius of curvature of the prism corners were characterized for their effects on the optical and electromagnetic properties. Bowties were characterized using LSPR, SERS, and photochemical near-field imaging. The results indicate that the radius of curvature of the prism corners has an important effect on the SERS abilities of a nanoparticle array. The trends described herein can be utilized to intelligently design highly sensitive SERS and LSPR biosensing substrates.