Surface plasmon resonance imaging of Au nano-partifcle modified DNA monolayers

A probe DNA monolayer modified with Au nano-particles was prepared on an Au thin film and used for DNA hybridization detection by surface plasmon resonance (SPR) spectroscopy. This Au particle modified probe DNA monolayer resulted in about a 3.5 times larger SPR angle shift according to the hybridization reaction, compared to that found in a non-modified probe DNA monolayer. By comparison of the SPR image of the particle modified and non-modified probe DNA monolayer, this modification method was shown to be useful in improving the SPR signal for the detection of the unlabelled DNA molecules.