Plasmonic Nanoceria: A Plasmon-Enhanced Nanohybrid for Rapid and Sensitive Detection of Ebola Glycoprotein

Abstract

Frequent Ebola outbreaks on an unprecedented scale in resource-limited countries have resulted in higher fatality rates for the human population. Thereby, the development of a biosensor platform that can be used for point-of-care (PoC) tests and simultaneously features high sensitivity and selectivity is urgently needed. Herein, an approach for formulating multifunctional nanocomposite materials, plasmonic nanoceria (PNC), is presented, and its application as a sensing platform for the detection of Ebolavirus glycoprotein (EGP) of the Zaire strain is demonstrated. The synthetic strategy for PNC allows optical tunability, a unique approach to amplify detection sensitivity introduced by encapsulating gold nanoparticles (GNPs) within the polymeric coatings of cerium oxide nanoparticles (NC). Through altered optical characteristics of GNPs within the PNC, which include changes in localized surface plasmon resonance (SPR), higher detection sensitivity is achieved. Following surface conjugation of PNC with EGP-specific antibodies, a quantitative detection limit as low as 10 pM (0.7 ng/mL) is achieved. Moreover, antibody-functionalized PNC exhibits faster, reproducible, and highly sensitive colorimetric readouts, with a detectable SPR shift in the presence of EGP. Importantly, the limit of detection of EGP evaluated in complex sample matrices was comparable to as attained in a simple buffer. Specificity studies suggest that the developed PNC nanoplatform allows for both detection and differentiation between Ebola virus subtypes. Overall, the formulated PNC holds great potential for the rapid, ultrasensitive, and on-site detection of biomarker EGP of the Zaire strain and can be customized for the detection of other pathogens.