Use of dusty plasmas for surface-enhanced vibrational spectroscopy studies

Dusty plasmas are low-temperature, weakly ionized gases containing micron- to submicron-sized solid particles that are charged by plasma collection currents. In this theoretical note, we propose the possible use of dusty plasmas as substrates for surface-enhanced vibrational spectroscopy studies, because of several possible advantages over some traditional substrates. Surface-enhanced Raman scattering, or surface-enhanced infrared (IR) absorption spectroscopy, has used metal colloids as substrates on which the analyte molecules are adsorbed. As compared with colloids, dust in plasmas have much faster charging times, are immersed in background plasma that is generally transparent to IR, can be composed of a wide variety of materials, are free of solvents, and allow a range of temperatures. Plasma properties also may lead to reduced aggregation as compared with colloids and may allow the use of different dust materials that have electromagnetic resonances in the IR as well as in the visible. Possible complications associated with the use of plasmas are also discussed.