This book covers the synthesis and applications of colloidal gold nanorods including their properties, approaches for various chemical synthesis, and different gold nanorod-based nanocomposites with their properties and application potentials. Furthermore, it covers the surface chemistry and functionalization of gold nanorods for numerous biomedical applications. Various applications of gold nanorods including optical probes, dark filed contrast agents, photothermal therapy agents, and plasmonic photocatalyst are covered, along with the toxicological aspects. Features: Covers all aspects of gold nanorods along with selected protocols Focuses on synthetic chemistry, optical property, and functionalization approach of colloidal gold nanorods Describes standard synthetic methods and advantages of gold nanorods in biomedical applications Includes authentic and reproducible experimental procedures Discusses applications like redox catalysts, catalyst promoters, delivery carriers, solar cell materials, and so forth This book aims at graduate students and researchers interested in nanotechnology and gold nanoparticles.