Metal nanoshells: a novel substrate for immunoassays

Summary form only given. Metal nanoshells are a novel class of nanoparticles with unique optical properties, including a tunable optical absorption and substantial enhancement of Raman scattering. Conventional roughened metal SERS substrates demonstrate optimal SERS enhancement at a single wavelength due to their fixed plasmon resonance. Metal nanoshells, however, possess a tunable plasmon resonance-permitting SERS in the Near-IR "water window" of 800-1300 nm, where deep optical penetration into biological samples should permit retrieval of Raman signals across tissue boundaries. This study examines the use of metal nanoshells as a substrate for the rapid, solution-based optical detection of analytes in complex biological solutions such as whole blood, using near-IR surface-enhanced Raman scattering.