Near-Field Lithography by Two-Photon-Induced Photocleavage of Organic Monolayers

摘要

We prove that the enhanced electromagnetic near-field around metallic nanostructures can be used for localized two-photon-induced activation of surfaces, obtaining a defined chemical pattern with nanometric resolution. Gold nanoparticles (Au-NP) are deposited on glass slides that were modified with a polysiloxane layer containing a nitroveratrylcarbonyl (NVoc) photore-movable group. Upon illumination with a femtosecond laser, the NVoc entity is removed. Due to the electromagnetic field enhancement of the nanoparticles, the threshold of this process is lowered in the nm-scale vicinity of the metal structures. Upon cleavage, an amine functional group is released, which can be used to site-selectively bind species with complementary chemical functionality on the surface. This method can be utilized for sub-wavelength chemical structuring.