Chemical sensors are becoming increasingly important in such diverse areas as industrial process control, safety, defense, medical monitoring, and climate change. As the application areas expand and become more demanding, the active portion of the sensor must perform at higher capacity. One solution to meet this challenge is to utilize nanostructured materials with unique morphological, electronic, and optical characteristics. Work in this program will examine the role of nanostructured materials as the active material in chemical sensors. Research areas will include the design, synthesis, and modification of organic and inorganic nanostructured materials (e.g., nanoparticles, single- and poly-crystalline nanowires, and nanomaterial assemblies) for high-performance sensing applications, their integration with existing and new sensing platforms, and their evaluation. In particular, we seek to elucidate the role of nanostructure and dimension in sensor-analyte interactions, and how they impact sensor-performance parameters. The materials may be applied to gas-phase or solution-based sensor systems using a variety of transduction mechanisms (e.g., chemiresistor, chemFET, electrochemical, optical, mass loading). Many opportunities exist for collaborative efforts on sensor development, evaluation, and application design.