Plasmonically enhanced electron escape from gold nanoparticles and their polarization-dependent excitation transfer along DNA nanowires.

Here we show plasmon mediated excitation transfer along DNA nanowires over up to one micrometer. Apparently, an electron excitation is initiated by a femtosecond laser pulse that illuminates gold nanoparticles (AuNP) on double stranded DNA (dsDNA). The dependency of this excitation on laser wavelength and polarization are investigated. Excitation of the plasmon resonance of the AuNPs via one- and two-photon absorption at 520 and 1030 nm, respectively, was explored. We demonstrate an excitation transfer along dsDNA molecules at plasmon supported four-photon excitation of AuNP cluster or at laser field driven nanoparticle electron tunneling for an alignment of the attached dsDNA to the polarization of the electric field of the laser light. These results extend the previously observed plasmonically induced three-photon excitation transfer along DNA nanowires to another nanoparticle material (gold) and the adapted irradiation wavelengths.