Surface plasmon resonance imaging: application in microbiology

Abstract

Surface plasmons can be defined as the collective oscillation of free electrons on a metallic surface. They were first observed back in the early 20th century, by the American physicist and inventor R.W. Wood, while he was studying the diffraction of light by a metallic grating. Wood observed very narrow absorption bands in the diffraction spectrum that would remain unexplained until 1941, when U. Fano demonstrated that they were associated with surface waves known today as surface plasmons. A similar phenomenon explains the colours of stained-glass windows in cathedrals, as the glass contains metallic nanoparticles with plasmon absorption bands in the visible spectrum.