Book excerpt: Nanoscale electrochemistry has revolutionized electrochemical research and technologies and has impacted other fields, including nanotechnology and nanoscience, biology, and materials chemistry. This book examines well-established concepts and principles and provides an updated overview of the field and its applications. The first two chapters contain theoretical background, specifically, theories of electron transfer, transport, and double-layer processes at nanoscale electrochemical interfaces. The next chapters examine the electrochemical studies of nanomaterials and nanosystems, as well as the applications of nanoelectrochemical techniques. Each chapter can be read independently, providing readers with a compact, up-to-date review of th