Background: Efforts in developing various colloidal nanoparticles (NPs) as theranostic
probes have been promising in the biomedical field. Specifically, colloidal gold nanoparticles (GNP)
have been extensively utilized as a theranostic probe for molecular imaging and drug delivery owing
to their unique physiochemical properties with excellent biocompatibility.
Objective: This review outlines and discusses the progress regarding gold nanoparticle synthesis
methods for controlled geometry (spherical, rod, and cage), surface functionalization (covalent and
non-covalent), and associated in vitro/in vivo cytotoxicity as well as some of the interesting diagnostic
(imaging) and therapeutic (photo-thermal, drug delivery) applications.
Results and Conclusion: GNP possesses several advantages compared to other traditional theranostic
agents, we firmly believe that GNP based clinical approach will gain continuous interest with increasing
numbers of innovations.