Surface-enhanced Raman scattering (SERS) biosensing based on nanoporous dielectric waveguide resonance

A measurement of antigen-antibody binding in the porous anodic alumina (PAA) waveguide layer via waveguide-assisted surface-enhanced Raman spectroscopy (SERS) was demonstrated. The highest SERS signals of dye-labeled antibody molecules were recorded under the waveguide resonance modes, where most of the light is confined in the waveguide layer to generate localized surface plasmon resonance of Ag nanoparticles under the evanescent field, resulting in an enhanced electromagnetic field. It is a useful configuration for biosensing. Results showed that the PAA waveguide is advantageous in sensing biomolecules with high sensitivity. We performed the SERS detection of immune-recognition with a concentration as low as 0.1 ng/ml level through this method.