Enhancing the sensitivity of surface-plasmon resonance sensors Academic Article uri icon


  • Surface-plasmon-resonance (SPR) sensing devices have attracted tremendous interest in the past decade, both from a fundamental-physics perspective and as highly sensitive devices for optical detection of small biological or chemical entities in liquids. 1 The two main sensor types are based on extended and localized surface plasmons (SPs). 2 The former are considered more classical since they have been known longer. Extended SPs are longitudinal electromagnetic (EM) waves in a 2D electron gas on the surface of metals. Localized SPs, on the other hand, have become more mainstream only in the last two decades. They occur in metallic structures with dimensions less than half the wavelength of the exciting EM wave. The incident EM field must—in either case—be polarized in the plane of incidence. This is referred to as transverse-magnetic (TM) polarization. A variety of …

publication date

  • January 1, 2009