Book excerpt: Biological and chemical warfare agents, including viruses, bacteria, and explosive and radioactive compounds, can induce illness or death in humans, animals, and plants. Plasmonic nanosensors as detection tools of these agents offer significant advantages, including rapid detection, sensitivity, selectivity, and portability. This book explores novel and updated research on different types of plasmonic nanosensors for analysis of biological and chemical threat agents. It covers a brief theory of plasmonic nanosensors, summarizes the state-of-art in the molecular recognition of biological and chemical threat agents, and describes the application of various types of nanosensors in the detection of these threat agents. This book • Brings together recent academic research from an interdisciplinary approach including chemistry, biology, and nanotechnology. • Discusses current trends and developments. • Describes applications of a variety of different types of plasmonic nanosensors. • Explores outlooks and expectations for this technology. Showcasing the latest achievements in plasmonic nanosensors, this book will appeal to researchers in materials, chemical, and environmental engineering as well as chemistry interested in exploring the application of sensors to support environmental monitoring and global health.