Optical characterization of multi-component Au-colloid-DNA complexes

Abstract

In this communication, we report on the results of experimental studies on the linking of Au colloids with different sizes (20, 50 and 80 nm in diameter) coupled by double-stranded DNA. Samples were characterized by optical transmission spectroscopy in the visible and near-infrared range and compared to transmission electron microscopy of the dried sample. The surface plasmon resonance of the Au particles coupled by DNA chains are recorded and compared with the spectra of isolated particles. In the cases of DNA chains functionalized with two thiol groups the spectra shows a broadening and a red shift of the surface plasmons which is a result of coupling the particles by this chains