Rapid, Affordable, and Near-Patient Disease Detection

Point-of-care (POC) diagnostics allow decentralization of disease detection, with analyses performed near the patient, reducing the time-to-result to enable earlier detection and treatment, better monitoring and management of diseases. This work focuses on advancing POC testing by applying cutting-edge nanotechnology, portable devices, and rapid methods of detection to measure a wide range of protein- and nucleic acid-based biomarkers. Isothermal nucleic acid amplification methods facilitate rapid amplification, decreasing system complexity and cost compared to PCR. Among the common isothermal nucleic acid amplification techniques, Recombinase polymerase amplification (RPA) stands out as the least complex to design and optimize, and offers the fastest time to result. We developed and evaluated the performance of a panel of RPA assays for detection of common bacterial urinary tract infection (UTI) pathogens. We also developed a quantitative RPA microbiome assay capable of determining the relative abundance of the physiologically-important bacterium Akkermansia muciniphila in human feces by eliminating contaminating DNA from RPA reagents. Lateral Flow Assays (LFAs) are a standard format for POC tests, as they are user-friendly, rapid, and affordable. We applied a smartphone-based lateral-flow immunoassay (LFA) with persistent luminescent nanoparticles (nanophosphors) as reporters to the detection of genital herpes seroconversion and dengue infection. POC smartphone devices equipped with mobile healthcare applications allow the immediate upload of results to facilitate better tracking and monitoring and prevent the spread of outbreaks. However, keeping up with evolving smartphone platform designs and creating a test that performs similarly across multiple smartphone devices are significant challenges. Here, we describe the development of the first one-step lateral flow fluorescent immunoassay for the detection of Anti-Müllerian hormone (AMH), a marker for ovarian reserve, and demonstrate quantitative point-of-need AMH detection on the portable ESEQuant LR3 Fluorescent Reader. Streamlining diagnostic testing to a patient’s physician's office would reduce the inconvenience, turnaround time, and the cost of testing, allowing for more frequent monitoring.