Science AAAS Highlight
Nanoplasmonic sensing and detection
by MARK I. STOCKMAN
Measuring minute amounts of chemical and biological objects in the environment and in living organisms is one of the most common and important tasks in chemistry, biology, medicine, environmental monitoring, transportation, homeland security, and defense. Although the existing methods of sensing and detection are numerous and powerful, they are not without shortcomings: insufficient sensitivity; long detection times; necessity for enzymatic, fluorescent, or radioactive labeling; high costs, and so on. Optical spectroscopic methods have the advantage of being fast, noncontact, and relatively inexpensive, but they are not necessarily sensitive enough.
Nanoplasmonics deals with optical phenomena localized at surfaces and interfaces of metals that are due to light-induced electronic excitations called surface plasmons (SPs). For a metal nanoparticle embedded in a dielectric, the SPs are oscillations of electric field and polarization localized in space. These are localized surface plasmons (LSPs), whose excitation frequencies depend mainly on the dielectric properties of the constituents and weakly depend on the system size. For extended systems, the SPs are electromagnetic waves, the so-called surface plasmon polaritons (SPPs), bound to the surfaces and interfaces and propagating along them (1, 2).
Full Article: Nanoplasmonic sensing and detection, Science, Vol. 348, pp. 287-288,
2. ↵ M. I. Stockman ,Opt. Express 19, 22029 (2011).
3. ↵ A. A. Yanik et al Nano Lett. 10, 4962 (2010).