How gold nanoparticles have stayed in the light: the 3M's principle.

Simultaneous advances in making, measuring, and modeling noble metal (plasmonic) particles--designated as the 3M's principle--have led to a perfect storm in discoveries and applications of gold nanoparticles. Three articles in this issue of ACS Nano illustrate this concept. First, exquisite control over gold nanorod length and diameter and testing of fundamental ideas are presented. Second, gold nanorods as localized surface plasmon resonance sensors to monitor the kinetics of antibody-antigen binding are reported. Third, strategies to prepare gold nanoshell substrates to enhance Raman scattering and infrared absorption are proposed. In this Perspective, we discuss how these reports fit into current challenges in plasmonics and how the prospects of localized surface plasmons will continue to shine when the right applications are revealed.