Construction of DNA-Au nanoparticles multilayer and its application to detection of DNA hybridization

We have developed a sensitive detection system for DNA hybridization containing DNA-Au nanoparticles (DNA-GPs) multilayer which leads to the enhancement of the detection sensitivity of surface plasmon resonance (SPR) signals. The SPR angular shift, which is the difference in the SPR angles before and after hybridization, becomes amplified with increasing number of layers of the DNA-GPs. A similar increase in SPR angular shift was obtained for the target DNA with low concentration. The reason for the enhancement is attributed to the interaction between Au nanoparticles and the Au film, as well as the increase in immobilized probe DNA content on the substrate.