Functionalized gold nanorods for nanomedicine: Past, present and future

Gold nanorods (GNRs) have been on the forefront in biophotonics due to their extremely attractive optical properties and their use in a variety of applications in biosensing and nanomedicine. In this review, we first present the synthesis and functionalization approaches and then describe the extraordinary optical properties of GNRs. Thereafter, we elaborate on the recent research advances in the use of GNRs for sensing, and highlight the increasing use of GNRs for in vitro and in vivo diagnostics and therapeutic applications. We also discuss the toxicity effects of GNRs on the body and environment and present an evaluation on the role of surface modifications in affecting the toxicity in biological systems. Finally, we provide concluding perspectives on the overall current status, challenges, and future directions for the use of GNRs in research and clinical applications.