Nanotechnology is the study of the controlling of matter on an atomic and molecular scale and is also very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly. This book gathers and presents data on nanotechnology. Chapter One examines the role of atomic particles and nanoparticles in catalysis. Chapter Two reviews the preparations of nanoporous microelectrodes, their physical and electrochemical characterization, their electrochemical behaviors, and their promising applications. Chapter Three studies controllable growth methods for device applications of gold nanorods. Chapter Four provides an overview of various antibody-nanoparticle conjugating modalities and their potential clinical application. Chapter Five reviews the numerous methods available to fabricate delivery systems depending upon the physicochemical properties of active ingredients and the polymers. Chapter Six discusses recent achievements in the field of development of different photoconverters (photodetectors and solar cells) based on nanoheterostructures with quantum dots of germanium on silicon.