The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is an inexpensive handheld smartphone device for rapid detection of the toxigenic cholera pathogen in environmental water sources. Contaminated water sources place populations at risk for contracting cholera. Once contracting the disease, patients with cholera exhibit symptoms of diarrhea, vomiting, and dehydration and, if left untreated, ultimately death. Wide-scale cholera outbreaks devastated Haiti in 2010 and Yemen in 2017, affecting over one million total individuals. Currently, methods used to detect the cholera pathogen in water involves a 3 to 5-day water collection and cell culture procedure. This project proposes a portable smartphone platform used to detect the cholera pathogen, Vibrio cholerae, in under 30 minutes at the water source. Smartphone connectivity, will also enable geomapped and time-stamped detection results. This novel and proactive approach for detection can enable organizations to remediate water sources prior to communities contracting and spreading cholera. Downstream, this technology will save the time and costs currently associated with cholera outbreaks and can be expanded to other infectious diseases.This SBIR Phase I project proposes to develop a rapid, cost-effective, and robust smartphone platform to detect Vibrio cholerae and automate the detection result at an environmental water source. The device performs isothermal DNA amplification assay combined with the novel sensing approach, particle diffusometry. This project proposes to characterize the specificity, sensitivity, and lower limit of detection of Vibrio cholerae detection on the smartphone platform. The detection results will be compared against current gold-standard quantitative DNA amplification methods. Further, a reagent storage method involving freeze drying will be used to eliminate the need for cold-chain storage. We will assess the long-term stability of our assay reagents through accelerated aging studies. Lastly, a low powered integrated heating unit will be designed to perform the isothermal DNA amplification assays in the handheld device. At the completion of this Phase I project, an integrated smartphone platform will be ready for field testing.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.