NASA needs an advanced sensing technology for in-line measurement of ionic silver in spacecraft potable water systems. Such a sensor should be small, robust, lightweight requiring low-power consumption. This sensor should be compatible with existing systems and capable of stable, continuous, and autonomous measurements of silver for extended periods of time. InnoSense LLC (ISL) will develop an innovative nanomaterial?enabled Silver ion Monitor (SilMonTM) based on ISLs patented microelectronic device platform. This project will support NASA needs expressed in 2020 NASA Technology Taxonomy, TX06 Human Health, Life Support, and Habitation Systems (TX06.1.2 Water Recovery and Management). In Phase I, ISL will: (1) design and fabricate the sensor with appropriate recognition molecule, and (2) evaluate the sensor performance. Feasibility will be demonstrated by achieving sensitive and selective detection of silver ion in the concentration range of 101000 ppb. In Phase II, we will optimize the sensor design, recognition chemistry and algorithm, fabricate prototypes and perform rigorous characterizations. Potential NASA Applications (Limit 1500 characters, approximately 150 words) During human exploration missions, SilMon will: (1) provide accurate and real-time silver ion concentration monitoring, (2) help optimizing the microbial control in Water Process Assembly by providing feedback to maintain an adequate level of silver ion in the water, and (3) ensure the safety of potable water. SilMons versatility can be adapted to monitor potable water for other analytes toward meeting NASA needs. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) SilMon will have significant commercial applications in the food industry, water and environmental monitoring, and water purification systems. As spin-off applications, SilMon can be modified with appropriate capturing agents for monitoring other ions or organic molecules.