Self-Sensing Surface Plasmon Resonance for the Detection of Metallic Nanoparticles

Surface plasmon resonance (SPR) is an established technique for label free sensing of bio-molecular species, including time-dependent reaction analysis. The typical Kretschmann configuration used requires a prism coated with a thin Au film of thickness around 50 nm and this is highly sensitive to local permittivity changes at or near to the interface. More recently researchers have incorporated Au nanoparticles onto the surface of the gold film to enhance the sensitivity by realising localised SPR. Gao et al created nano-composite Al2O3 films incorporating Au nanoparticles for the detection of low concentrations of streptavidin, for concentrations of < 50 nM. Similar work has seen Au nanoparticles embedded in polymers