Project Summary Substance Use Disorders (SUD) has become a major public health crisis of our times. Although medications for SUD have been available, many patients often encounter significant barriers to receiving a diagnosis and treatment for SUD because there are no devices for rapid and low-cost quantitative measurement of drug concentrations and their metabolites that can be used for monitoring the compliance and metabolism of SUD medication drugs (buprenorphine, Methadone, Naltrexone) in patients who are undergoing opioid dependence therapy or pain management in low-resource setting or at home. We propose to develop a low-cost, disposable, point-of-use, highly sensitive and specific non-instrument urine test strip that enables the rapid quantification SUD medication drugs (buprenorphine, Methadone, Naltrexone) and their metabolites in patients’ urine. The test requires no special training to operate and qualitative yes/no and quantitative results are visibly obtained within ten minutes while quantitative results can be measured with mobile-phone-based strip reader. To circumvent the technical challenge of current lateral flow assay (LFA) strip’s ability to measure low concentration of SUD medication drugs and their metabolites, we will implement innovative strip architecture of strip built-in signal amplification by Pt nanoparticle amplified chemiluminescent(CL) signal readout which enhance the detection sensitivity. To increase the specificity for drug/metabolite detection, we propose a new lateral flow assay format by using specific peptide against the immunocomplex of analytes-capture antibody selected from Phage-peptide display library in the LFA. Furthermore, a Lab-on-Mobile-Device Apps (mReader™) is tailed for strip image acquisition and quantitative analysis. We will optimize reagent concentrations and LFA parameters along with statistical validation of dynamic range, specificity, and sensitivity in Phase I project. The completion of these proof-of-concept studies will demonstrate the ability of this new type LFA to measure drug concentration in urine samples. In future Phase II, we will: 1) optimize the LFAs configuration to reduce false negatives and false positives to ensure reliable detection, 2) design and develop any associated devices (cassette, packaging and labeling), 3) develop smartphone based quantitative analysis of the LFA test results and data processing Apps recording and wireless communication of test results, and 4) develop manufacturing processes for pilot scale production of 2000 LFAs and validate the cannabis saliva test with a large cohort of samples (> 250 clinical samples). At the end of Phase II, the colorimetric LFAs will be ready for transferring to full-scale automated manufacturing, and the final LFA device will be produced at large scale for clinical validation towards a defined 510(k) clearance by the FDA.