Project Summary The overall goal of the proposed research is to create an effective and scalable monitoring device as a tool for drug screening to decouple the stigma associated with Cannabis Use Disorder (CUD) and cannabis consumption, while enhancing public safety. Through the first truly point-of-need (PoN) device for accurate THC quantification in saliva, XALIVA®, Ricovr Healthcare provides significant advances for drugs-of-abuse (DoA) detection tools compared to what is currently on the market. Coupled with conventional counselor-delivered intervention, XALIVA® will eliminate the burden of stigma in monitoring processes in workplaces, roadsides, remote testing, and other public places (hospitals, schools), improving outcomes for patients by providing sensitive, specific, and accurate detection of recent THC use, with a perfect fit with the window of impairment. For this Phase I proposal, feasibility of a plasmonic fiber-optic absorbance biosensor (P-FAB) and the immunoassay-based detection method with gold nanoparticle (AuNP) antibody conjugates to monitor THC levels in oral fluid will be proven, and further development of the PoN device and workflow will be achieved. The XALIVA® device is simple to use, requires no training, and its ability to detect a variety of analytes at ultra- sensitive concentrations ranging from 1 fg/mL to 1 ug/mL has been already demonstrated. Ricovr Healthcare solves the limitations of current THC saliva screening devices which are struggling with sensitivity ranges, workflow, and cost. Further, Ricovr has distinct advantages compared to the current standard urine screening devices, which only reveal metabolites rather than the parent compound, are invasive, stigma-loaded, take too much time to result, and are easily manipulated.