Infectious diseases cause 50,000 deaths daily. Early detection is essential for timely treatment and prevention. However, current diagnostic methods face limitations in long reaction time, high costs, or require specialists to conduct labour-intensive procedures. To tackle this, we developed a fast and effortless detection system, which integrates a novel microrobotic sensing probe capable of detecting a specific pathogen with magnetic field and fluorescence. Our first product QuickCAS targets the detection of C. difficile infection, one of the most typical infections in hospitals. This technology has filed a US nonprovisional patent and a Chinese invention patent.