Abstract
Graphene oxide-wrapped gold nanorods (GO@AuNRs) offer efficient drug delivery as well as NIR laser photothermal therapy (PTT) in vitro and in vivo. However, no real-time observation of drug release has been reported to better understand the synergy of chemotherapy and PTT. Herein, surface-enhance Raman spectroscopy (SERS) is employed to guide chemo-photothermal cancer therapy via a two-step mechanism. In the presence of GO as an internal standard, SERS signals of DOX (doxorubicin) loaded on GO@AuNRs are found to be pH-responsive. Before DOX@GO@AuNRs are endocytic, both DOX and GO show strong SERS signals. However, only DOX signals start decreasing after the DOX@GO@AuNRs enter acidic microenvironment such as endosomes and/or lysosomes. This plasmonic antenna could be used to identify the appropriate real-time to apply PTT laser during chemo-photothermal therapy.