For long-term exploratory space travel, there will be a critical need for in-situ diagnosis and assessment of biological specimens from symptomatic astronauts, especially, disease pathogens (virus, bacterium, or fungus) and microbial contaminants. Hence, a real-time, non-culture-based microbial detection, identification and quantification system for on-flight monitoring and evaluation of pathogens from astronauts, or the space environment, is strongly desired. The success of such diagnostic tasks critically depends upon the degree of automation and reliability of such trace level detection. To meet this need, we propose to develop a novel miniaturized, point-of-care (POC) detector for reagent-free, no-culturing, in-situ diagnostics of disease pathogens. The envisioned device will be compact, lightweight, fully integrated and automated (requiring minimum human intervention), and highly cost-effective and power-efficient. In Phase I, we will develop a new type of electrochemical molecules and fabricate solid electrode-based probe for in-vitro demonstration of accurate and effective signal transduction of selective binding of pathogenic cells to the electrode as proof-of-principle. In Phase II, the electrode probe will be optimized to increase specificity, sensitivity, stability, and the response to regular biological samples. Finally, the sensor will be integrated with a compact handheld instrument for data collection, analysis and processing and interfacing with existing NASA space instrumentation for both terrestrial and microgravity environments evaluation.