Optical biosensor based on localized surface plasmon resonance with high spatial resolution

We are using a gold nanoparticle coated film to achieve high spatially resolved biosensing that is based on localized surface plasmon resonance (LSPR). This special film possesses the unique optical properties of being not sensitive to the changes of incident angle and relies exclusively on the spectral shift of absorption peak for biosensing. This uniqueness enables it to be compatible with high numerical aperture (NA) optics and to achieve high spatial resolution. We demonstrate a spatial resolution of 25 mum assuming a maximum of spectral fluctuation of 0.1 nm is acceptable.