University of Massachusetts, Boston,
Keywords: gold, silver, nanoparticles, POC, diagnostic device
Summary:Rapid point-of-care (POC) diagnostic devices are needed for field-forward screening of severe febrile illnesses such as Dengue, Zika, Ebola, Chikungunya, and others. Multiplexed rapid lateral flow diagnostics have the potential to distinguish among multiple pathogens, thereby facilitating diagnosis and improving patient care. We present a platform for multiplexed pathogen detection which uses gold and silver nanoparticles (NPs) conjugated to antibodies to sense the presence of biomarkers for different infectious diseases. New capabilities for immunoassays are enabled by using the material and size dependent properties of the gold NPs used in the assay. For example, nanoparticles have tunable optical properties, where synthesis of different sizes and shapes can result in particles with different colors. We leverage this property to make multiplexed diagnostics that can differentiate between disease biomarkers by color. Because positive test lines can be imaged by eye or a mobile phone camera, the approach is adaptable to low-resource, widely deployable settings. This design requires no external excitation source and permits multiplexed analysis in a single channel, facilitating integration and manufacturing. In addition, the plasmonic properties of noble metal particles can be used for high sensitivity detection methods such as surface enhanced Raman spectroscopy (SERS). We discuss how we use nanoparticles as SERS “nanotags” for multiplexed detection of different viral diseases.