Surface modifications of gold nanorods for applications in nanomedicine

Gold nanorods (GNRs) are appealing nanostructures for a wide variety of nanomedicine-based diagnostic and therapeutic approaches against untreatable diseases. Indeed, they possess unique and extraordinary optical features, which if conveniently stressed, would bring several benefits to non-invasive theranostic treatments. Major concerns regarding their practical application are derived not directly from GNRs but from molecules linked onto their surface, which could be source of toxicity as well as powerful allies for treatments' enhancement. Thus, specific and tailored surface modification of GNRs with several active moieties has become a crucial factor for their development. In this review, crucial breakthroughs and major possibilities deriving from the surface decoration of GNRs for final nanomedicine applications, as well as progress in therapy and diagnosis relying on the functionalization of these nanosystems will be summarized and discussed.