Strategies for nanoplasmonic core-satellite biomolecular sensors: Theory-based Design.

We present a systematic theoretical study of core-satellite gold nanoparticle assemblies using the Generalized Multiparticle Mie formalism. We consider the importance of satellite number, satellite radius, the core radius, and the satellite distance, and we present approaches to optimize spectral shift due to satellite attachment or release. This provides clear strategies for improving the sensitivity and signal-to-noise ratio for molecular detection, enabling simple colorimetric assays. We quantify the performance of these strategies by introducing a figure of merit. In addition, we provide an improved understanding of the nanoplasmonic interactions that govern the optical response of core-satellite nanoassemblies.