Clostridium difficile (C. difficile) is the most common infectious cause of diarrhea in hospitalized patients. Current commercially available tests cannot meet all the requirements of being rapid, low cost, sensitive, and selective. This proposed project will develop a novel platform to achieve the above goals. The success of the proposed research will make several broad scientific impacts. First, the proposed portable sensing platform will be extended for a broad range of applications. Second, it will enrich the fundamental knowledge of how nanostructured surfaces will affect the sensing performances. The acquired knowledge of nanostructured electrodes on the acrylic microfluidic platform can impact sensing research on other grand challenges, such as food safety and water systems. Research results will be disseminated to reach broader audiences by a) course development, b) incorporation into project-based learning for undergraduate and graduate students, and c) involvement of underrepresented groups, especially female students.<br/><br/>This proposal aims to develop portable, easy-to-fabricate acrylic microfluidic devices based on novel electrochemical impedance spectroscopy (EIS) analysis of C. difficile enabled by nanospiked electrode surfaces. Specifically, we propose to combine engineering of nanospiked surfaces with a soft lithography technique to fabricate repeatedly controllable electrochemical electrode with low cost. We anticipate such electrodes will enhance the sensitivity thanks to the high area-to-volume ratio and small size of nanospikes on the surface. The nanospiked electrodes will be implemented on an acrylic-tape microfluidic platform following a simple fabrication process. The capability of the developed portable device for C. difficile sensing will be evaluated to guide the device deign. We anticipate the outcomes of the study will include 1) a thorough understanding of nanobiosensing performance, 2) a transformative method for engineering nanospiked electrochemical biosensors platforms, and 3) portable acrylic microfluidic devices with nanospiked electrodes for point-of-care biosensing of C. difficile.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.