Project Summary: Heart failure (HF) affects 5.7M people annually in the United States with 1 in 9 deaths linked to the disorder. Measuring diagnostic and prognostic biomarkers at the point of care is key for reducing HF-related deaths but invasive blood-based diagnostic tests require extensive resources and are expensive. A critical need for sensitive assays that utilize non-invasive samples remains a pressing need for point-of-care diagnostics. Here, we propose to develop an innovative solution to rapid, sensitive, and inexpensive measurements of biomarkers in saliva that are correlated with HF. To address this need, a paper-based analytic device (PAD) that combines saliva sample processing with sensitive electrochemical biosensors to detect galectin-3 (Gal-3) and s100A7 as biomarkers of HF in saliva will be developed. The project consists of two aims, 1) demonstration of a sensitive, selective electrochemical PAD for s100A7 and Gal-3 and 2) development of a PAD that can rapidly and efficiently process saliva of varying viscosities in minutes. This project is an international collaboration between the Henry group at Colorado State University (CSU) and the Punyadeera group at the Queensland University of Technology (QUT) in Australia. The international collaboration is justified because the Henry group has expertise in PADs and the Punyadeera group has experience with saliva-based diagnostics. Once successful, we will expand both the number and type of biomarkers for both cardiovascular disease and head/neck cancers. We will also be poised to expand on-going clinical studies of saliva-based biomarkers to further validate their use as non-invasive biomarkers.