Hydrogen Sulfide (H2S)is the leading chemical agent causing human fatalities following inhalation exposures. The overall aim of this project is to develop and produce an inexpensive, highly selective and sensitive solid-state chemical micro-sensor with low power consumption that is suitable for rapid detection of very low-level (ppb) concentration of H2S in ambient air. The technology principle used to develop the micro-sensor is based on the knowledge that H2S is adsorbed into gold at an operating temperature range. By using a gold thin-film, and MEMS technology, we will produce a micro-sensor with the following specifications 1 mm x 1 mm micro-sensor, 3 seconds response and recovery time, 10 mW power consumption, and detection in the ppb range. Phase I will investigate the feasibility of the design, fabrication, testing, and validation of the micro-sensor in collaboration with researchers from the Integrated Nanosystems Research Facility at the University of California Irvine. During Phase II, the innovative solid-state micro-sensor will be integrated in a miniaturized battery powered wireless instrument for applications in biomass fouling detection.