In this book, the authors present current research in the study of the synthesis, optical properties and applications for cancer treatment of gold nanoparticles. Topics discussed include the use of gold nanoparticles in cancer treatment and biomedical applications to target tumors and provide detection, drug carriers, gene silencing and radiotherapy; gold nanoparticle fabrication by laser ablation technique and their optical and morphological study; gold nanoparticles for metabolite imaging; formation of gold nanoparticles inside the corona of amphiphilic triblock copolymer micelles; and the intracellular delivery of gold nanoparticles and their application in nanomedicine.