Early and accurate diagnosis of infectious disease is critical to the delivery of timely and appropriate treatment that improves patient care, reduces the economic healthcare burden, and prevents disease transmission. However, access to gold standard detection of nucleic acids (DNA and RNA) is typically limited to high resource hospitals with extensive laboratory facilities. In order to bring these intricate analyses out of the lab and to the point of care, diagnostics must balance robustness, ease of use, accuracy, and cost. Here, we present a novel detection device that is designed to meet these needs by integrating the simplicity and scalability of commonly used paper-based lateral flow immunoassays (LFIAs), such as pregnancy tests, with highly sensitive nucleic acid amplification. Our paper-based platform that has potential to be scaled via roll-to-roll manufacturing for affordable and reliable molecular diagnostic devices at the point of care. This fully-integrated microfluidic rapid and autonomous analytical device (microRAAD) is completely automated from sample-in to result-out [1]; minimizing sample preparation and time-critical steps to enable robust infectious disease detection even in remote settings.

Leveraging a number of innovations in fluidic control [2], low-power heating [3], and novel assay designs, our sample-to-answer device can enable detection of pathogens from diverse sample matrices at clinically relevant pathogen levels and has recently been demonstrated to detect HIV from blood. Inside microRAAD, we incorporate heat-stable amplification reagents, thermally-actuated wax valves for fluidic control, and low-resistance silver ink resistors with a temperature control circuit for USB-powered heating. We perform loop-mediated isothermal amplification (LAMP) and visualize these products via LFIA, resulting in an integrated, sample-to-answer test that runs in under 90 minutes. Human-centered design studies were performed to ensure usability and readability of test results by minimally trained users [4]. To run the test, the user simply adds their sample and a wash buffer, seals the test, and connects the device to a cellphone or battery. Based on preliminary results in the laboratory, the microRAAD device has potential to enable early and rapid detection of highly infectious diseases at the point-of-care.