A new sensor substrate supports Surface Enhanced Raman Spectroscopy. A ceramic electride is demonstrated to provide surface enhanced Raman scattering. This provides a sensitive method for monitoring the chemistry and electronic environment at the electride surface. The electride, an ionic crystal in which the electrons serve as anions, is a conductive calcium aluminate with a mayenite structure. The textured electride surface is found to strongly enhance the Raman scattering of an organic analyte at 532-nm and 785-nm excitation wavelengths. This provides a sensitive method for monitoring the chemistry and electronic environment at the electride surface.
Electrides are a class of ionic compounds where electrons are not localized on specific atoms or molecules, but occupy sites usually populated by anions. In electrides, the electrons are not completely delocalized as in metals, and may be regarded as a crystalline form of solvated electrons. Electrons occupying the anionic sites have unusual properties as a result of their small mass compared to typical anions. The chemical, optical, magnetic, and electrical properties of electrides have potential applications in electroactive materials and photonics.
This invention is owned by NASA, and a patent application has been filed. Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to the Patent Counsel, NASA Management Office–JPL. Refer to NPO-49086.