Surface-plasmon driven DNA dehybridization is a topic of intense current interest due to its highly promising potential for enabling light-controlled gene therapy: it is also of inherent interest as a light-driven nanoscale actuation process. In this study we formulate an Au nanoshell-based complex designed to release single-stranded DNA (ssDNA) from its surface when illuminated with plasmon-resonant light. This system allows us to examine DNA dehybridization induced by excitation of localized surface plasmons on the nanoparticle, relative to the thermal DNA dehybridization (melting). The dehybridization temperatures, and the percentage of DNA released per nanoparticle, differ markedly between the two processes. (C) 2009 Elsevier B. V. All rights reserved.