Infection with Human Immunodeficiency Virus (HIV) remains one of the greatest challenges to global health. Over 33 million individuals are estimated to be infected worldwide and, without treatment, most will die within 10 years. The last 15 years has seen great progress in the development of new treatments for HIV. Today, most adults diagnosed with HIV can hope to have a life expectancy close to that they could expect without HIV infection. Over the last 10 years these technological advances have driven a substantial global effort to give access to treatment for all those infected with HIV. Recent estimates suggest nearly 8 million people are accessing treatment worldwide. Despite this success, there are major challenges remaining to deliver care to those that need it. One of the major challenges is the ability to monitor those on treatment to ensure that their medication is working by measuring the amount of virus circulating in their blood. It is that challenge that this project aims to address. Monitoring the level of a patient's HIV virus in their blood (or "viral load") currently relies on centralised laboratory services. A rising viral load can suggest the medication is failing and the need to be assessed for a change of treatment. Even if they are well, most patients on treatment will have their "viral load" measured at least twice a year and, more commonly, four times a year. In the highest burden areas of the world, this creates an unsustainable strain on the infrastructure. Even where patients can access treatment and monitoring, centralised services mean patients have to make a return visit for their results. This is often a significant undertaking, particularly in rural areas, and many results are lost or not acted upon. This project aims to develop a novel method for detecting the HIV virus in a patient's blood. It uses a method suitable for use at the point-of-care (POC), in other words it can be used at the bedside, the clinic or in the community, wherever the patient is. It uses a technology that is ideally suited to resource-poor environments that are poorly served by central laboratories. The technology can operate from a handheld, battery-powered device without the need for a sample to be handled in a laboratory and in a system that can be operated with minimal training producing a rapid result (within 30 minutes) while the patient waits. The use of technology similar to that used in mobile phones will allow a product to be manufactured at scale at a cost that would be affordable in those parts of the world where it is needed the most.