Rapid point-of-care (POC) diagnostic devices are needed for field-forward screening of severe acute systemic febrile illnesses. Multiplexed rapid lateral flow diagnostics have the potential to distinguish among multiple pathogens, thereby facilitating diagnosis and improving patient care. The colored line that provides a visual readout for test results are due to noble metal nanoparticles conjugated to antibodies that can recognize the biomarker of interest. Because 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. Here, we present results in which we tune the physical properties of the nanoparticle in order to impart new capabilities to the lateral flow diagnostic. The size and shape dependent optical properties of noble metal nanoparticles can be tuned to optimize diagnostic performance and impart new capabilities. We developed a platform for multiplexed pathogen detection using multi-colored prism-shaped silver nanoparticles (AgNPs). AgNPs of different sizes were conjugated to antibodies that bind to specific biomarkers. Red AgNPs were conjugated to antibodies that could recognize the glycoprotein for Ebola virus, green AgNPs to those that could recognize nonstructural protein 1 for dengue virus, and orange AgNPs for non structural protein 1 for yellow fever virus. Presence of each of the biomarkers resulted in a different colored band on the test line in the lateral flow test. Thus, we were able to use NP color to distinguish among three pathogens that cause a febrile illness. We will also discuss the synthesis and characterization of Au nanoparticles of different shapes, such as Au nanostars, and their use in lateral flow tests. Finally, because lateral flow assays are complex environments and can result in many complex interface issues, manipulation of the bio-nano interface is critical. We will discuss studies of how NP surface chemistry modifications and antibody conjugation strategies impact the lateral flow test performance.

Noble metal nanoparticles for rapid diagnostics

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.