SERS Biosensors

      

Surface-enhanced Raman Scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces. Compared to the conventional technologies, SERS-based bioassays demonstrate high sensitivity, robustness, efficiency and point-of-care testing capability compared to conventional technologies such as ELISA and PCR. In the SERS-based immunoassay, biosensors labeled with different Raman dyes are developed for multiple antigens detection. Target antigens are detected by capture with silica-encapsulated gold nanotags and magnetic nanoparticles conjugated with polyclonal antibodies.

   

The magnetic pull-down resulted in aggregation of the immunocomplexes, and the silica-encapsulated nanotags provided distinct spectra corresponding to each antigen captured in multiplex detection. Previous work published in our lab has demonstrated simultaneous femtogram-level detection limits for two antigens with one single SERS-based immunoassay and picogram-level detection limits for three antigens. Current work focuses on the adaptation of the assay for field studies in wild birds in northwest Wyoming.