Hydrazine, a volatile and flammable colorless liquid, is classified as a carcinogen by the US Environmental Protection Agency. It can cause chromosome aberrations and negatively affect the lungs, liver, spleen, thyroid gland, and central nervous system. NASA's existing hydrazine measurement technology is sensitive, selective and reliable, but it takes 15 minutes to collect and analyze a sample. For future missions beyond Low Earth Orbit, NASA will need a measurement system that responds within 30 seconds without any performance limitations such as lack of specificity and maintenance challenges. To address NASA needs, InnoSense LLC (ISL) proposes to develop micro-electro-analytical sensor for rapid monitoring of hydrazine (Micro-Zin) in the presence of ammonia in spacecraft cabin atmosphere (SCA) for long-term performance without maintenance. Micro-Zin builds on ISL's nanomaterial-based sensor technology and electronic data processing systems. In Phase I, ISL will design and fabricate a Micro-Zin working model. To establish feasibility, we will characterize Micro-Zin's sensitivity, selectivity, response time, and reliability. In Phase II, we will optimize sensor performance with an appropriate prototype.