Nano-gap-Enhanced Surface Plasmon Resonance Sensors

Nano-gap-Enhanced Surface Plasmon Resonance Sensors:

Abstract

This paper analyzes how dual-mode surface plasmon resonance sensors can be further improved if one were to introduce small
(∼20 nm) gaps in the film surface. First, a figure of merit, the sensor’s limit of detection (LOD), is defined in order to
optimize the design of the nano-gap sensor. Secondly, the LOD of this design is compared with that of an optimized planar
dual-mode design. Through this analysis, it is shown that the LOD of the planar sensor can be improved upon by around a factor
of 7 when compared with the nano-gap-enhanced design. Furthermore, with the nano-gap design, the lower wavelength plasmon
mode demonstrates remarkably improved selectivity when compared with the conventional sensor. In order to explain these results,
the dispersion of each plasmon mode along with the electromagnetic field profiles are modeled and analyzed.

• Content Type Journal Article
• Pages 1-11
• DOI 10.1007/s11468-011-9276-6
• Authors
  • Phillip Donald Keathley, Department of Electrical and Computer Engineering, College of Engineering, University of Kentucky, 453 F. Paul Anderson Tower, Lexington, KY 40506-0046, USA
  • Jeffrey Todd Hastings, Department of Electrical and Computer Engineering, College of Engineering, University of Kentucky, 453 F. Paul Anderson Tower, Lexington, KY 40506-0046, USA

• Journal Plasmonics
• Online ISSN 1557-1963
• Print ISSN 1557-1955