A Smartphone Device That Can Detect HIV in 15 Minutes!

A team of researchers from Columbia University have developed a low-cost smartphone dongle that can detect HIV and syphilis in just 15 minutes by using a finger-prick of blood. This device can perform a point-of-care test that simultaneously detects three infectious disease markers. A first of its kind, it can replicate all mechanical, optical, and electronic functions of a lab-based blood test. It performs an enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy: all necessary power is drawn from the smartphone. The accessory or dongle easily connects to a smartphone or computer and was recently piloted by health care workers in Rwanda. They tested whole blood obtained via a finger prick from 96 patients who were enrolled into prevention-of-mother-to-child-transmission clinics or voluntary counselling and testing centers. According to lead researcher, Samuel K Sia, "Our work shows that a full laboratory-quality immunoassay can be run on a smartphone accessory. Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones. This kind of capability can transform how health care services are delivered around the world.” Sia's team developed the dongle to be small and light enough to fit into one hand. The team has made two main innovations to the dongle to achieve low power consumption, a must in places that do not always have electricity. They eliminated the power-consuming electrical pump by using a "one-push vacuum," where a user mechanically activates a negative-pressure chamber to move a sequence of reagents pre-stored on a cassette. The process is durable, requires little user training, and needs no maintenance or additional manufacturing. Moreover, they removed the need for a battery by using the audio jack for transmitting power and for data transmission. And, because audio jacks are standardised among smartphones, the dongle can be attached to any compatible smart device in a plug-and-play manner. They have estimated the dongle to have a manufacturing cost of USD 34.