Aptasensors: Amplification of Resonant Rayleigh Light Scattering Response Using Immunogold Colloids for Detection of Lysozyme (Small 20/2013)

An individual nanoplasmonic aptasensor is effectively exploited to detect lysozyme utilizing its adsorption on a DNA aptamer bound to a Au nanoparticle and its interaction with an antibody bound to another Au nanoparticle. S. J. Sim and co-workers report on page 3485 that the optical plasmonic resonance coupling of the larger Au nanoparticle with the smaller immunogold colloids causes a strong resonance peak shift and the light scattering color changes (green to red) of corresponding nanoparticles under the incident light (white) of the dark-field microscope. An increase of up to 380% in the LSPR λmax shift is demonstrated compared to the non-coupling shift.