Arrays of Plasmonic Nanoparticles Assembled on Patterns of Polymer Brushes Fabricated by Soft Lithography

This work employed end-grafted poly ethylene glycol PEG and hydroxyl-terminated poly 2-vinylpyridine P2VP polymer chains for selective immobilization and patterning of plasmonic nanoparticles NPs . A soft lithographic method which called micromolding in capillaries MIMIC used in this study. The polymers are deposited the capillary flow by the channels which formed by an elastomeric mold and substrate. The localized coatings are referred as polymer brushes and show great promise in the assembly of NPs due to the tunable interaction between the polymer chains and particles. The results show that the width of patterns defined by the channels is smaller than 1.5 µm with a length of around 0.5 cm. Also, the heights of the patterns are ~3.5 nm for P2VP and ~10 nm for PEG. The fabricated structures exhibited high levels of plasmonic activity and surface enhanced Raman scattering due to the immobilized Au NPs. The patterning polymer brushes and plasmonic NPS over large areas by a low-cost process show great promise for a variety of applications that range from molecular sensors to biotechnolog