Detection of DNA immobilization and hybridization on gold/silver nanostructures using localized surface plasmon resonance

In this study, we used localized surface plasmon resonances (LSPR) to observe a phenomenon of binding of DNA on Au and Au/Ag nanostructure arrays. Au and Au/Ag nanostructures of various geometric sizes and metal compositions were fabricated by colloidal lithography technique. The immobilization of capture DNA and subsequent hybridization with target DNA on the nanostructures caused the shift of maximum peak in LSPR spectra of the nanostructures. Using the peak shift, the immobilization of capture DNA was clearly verified in a nondestructive manner and hybridization with complementary target DNA was reliably differentiated from the non-specific binding with noncomplementary DNA. This work firmly implies that the LSPR spectra of the nanostructrues can be efficiently utilized to achieve a novel strategy for the detection of DNA on the nanostructures.