Architectures of bilayered gold nanoparticles on UV cross-linked poly(4-vinylpyridine) thin films

A generic approach for immobilizing gold nanoparticles (GNPs) and the construction of multilayered gold structures are reported. The process involves the use of UV cross-linked poly(4-vinylpyridine) (P4VP) thin films for the immobilization and construction of multilayered GNP architectures. P4VP thin films were prepared by spin-coating of the polymer solution onto silicon wafer substrates which was then cross-linked via UV exposure. GNPs, about 70 nm were immobilized via electrostatic adsorption onto the P4VP films. Further, these monolayer surfaces containing GNPs were capped with a bifunctional cross-linker, 1,6-hexanedithiol (HDT). To the additional end termini of HDT, a second layer of GNPs (approximately 20 nm) was assembled. The self-assembly of 1,6-hexanedithiol on the immobilized GNPs and the bilayered architectures were investigated by atomic force microscopy (AFM), filed emission scanning electron microscopy (FE-SEM), and UV-Vis absorption spectroscopy.