The goal is to develop novel, low-cost, real-time point-of-care (POC) assays for antiretroviral drug adherence monitoring: - Rapid point-of-care methods that measure long-term (> 7 days) adherence to antiretroviral drugs - Ability to measure drug levels in various biological matrices, e.g., urine, hair, dried blood spots, etc. - Ability to monitor PrEP adherence, ART adherence to trigger adherence interventions, the long-tail associated with long-acting ART or PrEP, and blood donations for PrEP or ART drug levels (as a risk indicator of HIV exposure or infection)