Near-Field Communication-Enabled Digital In-Field Diagnostics

Firat Guder and Tony Cass of Imperial College London in the United Kingdom along with George Mahuku and James Legg at the International Institute of Tropical Agriculture in Tanzania are developing a low-cost, disposable electrochemical lateral flow assay for smartphones to rapidly detect crop viruses in the field and enable broad crop disease surveillance in low-income regions. Most diagnostic tests are laboratory-based, expensive, and slow. Their approach is based on chemical amplification to increase sensitivity, and detection by nucleic acid aptamers, which are more stable and less costly than antibodies. In Phase I, they selected aptamers for viruses that cause maize lethal necrosis and cassava brown streak disease, optimized the silicon ink for printing in nitrocellulose membranes, developed mobile and cloud/web applications for data storage and visualization, and laboratory-tested the assay. In Phase II, Firat Guder and colleagues will complete and validate the assay, refine the applications, and manufacture 1,000 prototypes and test them in the field in East Africa.