Monitoring controlled release of payload from gold nanocages using surface enhanced Raman scattering

Novel organic and inorganic nanostructures for localized and externally triggered delivery of therapeutic agents at a target site have received immense attention over the past decade owing to their enormous potential in treating complex diseases such as cancer. Gold nanocages, a novel class of hollow plasmonic nanostructures, have been recently demonstrated to serve as carriers for the delivery of payload with external trigger such as light or ultrasound. In this article, we demonstrate that surface enhanced Raman spectroscopy (SERS) can be employed to noninvasively monitor the release of payload from these hollow plasmonic nanostructures. The large enhancement of electromagnetic (EM) field at the interior surface of these nanostructures enables us to monitor the controlled release of Raman-active cargo from nanocages. Considering that SERS can be excited and collected in near-infrared (NIR) therapeutic window, this technique can serve as a powerful tool to monitor the drug release in vivo, providing additional control over externally triggered drug administration.