Rapid Fingerstick Diagnostics for Opioid and Stimulant Use Disorders - Project Summary Opioid and stimulant use disorders (OUD/StUD) represent an escalating public health crisis in the United States, with more than 107,000 overdose deaths reported in 2022, driven predominantly by synthetic opioids (e.g., fentanyl) and increasing use of stimulants like methamphetamine and cocaine. Despite available treatments, <10% of individuals with substance use disorders receive the care they need. Existing diagnostic methods, which rely on urine and blood tests, are hindered by logistical constraints (specialized facilities, multiple sample collections, laboratory processing, and delayed results). Moreover, they do not simultaneously assess for the presence of all opioids, stimulants, and their metabolites, nor do they screen for related critical health indicators such as pregnancy, cardiac injury, cardiovascular stress, inflammation, bacterial infections, clot formation, and neuronal and brain injury. These barriers impede timely intervention and effective monitoring of patients, particularly in underserved and remote areas. The development of an innovative, rapid, and comprehensive diagnostic tool is urgently needed to bridge this gap. Such a tool would enable early detection and continuous monitoring of OUD/StUD, facilitating timely medical interventions that could significantly reduce the morbidity and mortality associated with these disorders. During this Phase I SBIR project, we will develop and validate a comprehensive Point-of-Need (PON) OUD/StUD multiplexed assay by focusing on the following key activities. Develop and Construct an Alpha-Prototype: we will design and build an alpha-prototype OUD/StUD multiplexed assay. Assess Laboratory Feasibility: the prototype will undergo rigorous testing with spiked whole blood samples to optimize detection and quantification for each target/biomarker type. We will evaluate key performance metrics such as accuracy, sensitivity, specificity, limit of detection (LOD), and limit of quantification (LOQ). Validate End- Point Capabilities with Clinical Samples: in collaboration with field leading experts, we will obtain and analyze clinical blood samples from patients with known OUD/StUD and compare the results to existing diagnostic standards to establish the efficacy of the OUD/StUD multiplexed assay. And lastly, we will carry out a comprehensive stakeholder engagement effort to ensure the technology meets the practical needs of end-users and foster early adoption and buy-in from key stakeholders in the healthcare community. This innovative diagnostic tool promises to transform the management of opioid and stimulant use disorders by providing rapid, accurate, and comprehensive health assessments. By enabling early detection, personalized treatment plans, and repeated/continuous monitoring, the OUD/StUD multiplexed assay will significantly improve patient outcomes and reduce the overall burden on the healthcare system. Through this project, we aim to provide a practical and accessible solution that can be deployed in a variety of settings, ensuring that high-risk populations receive timely and effective care.