Orthogonal functionalization of silicon substrates using self-assembled monolayers.

A fabrication process for multifunctional surfaces is designed leading to five different functional moieties (amine, thiol, carboxylic acid, fluoro, and methyl) being present on a single structured surface. The multifunctional surface is created by combining UV-ozone patterning, electro-oxidative lithography, the local deposition of self-assembled monolayers (SAMs), and surface modification schemes. Besides the characterization with conventional surface-sensitive techniques, the nature of the locally functionalized regions is demonstrated by self-assembly of three different probe nanomaterials (Si nanoparticles, Au nanoparticles, and hydroxyl functionalized micelles). A versatile fabrication approach for complex surfaces with addressable functionalities can be created, and it was possible to integrate five different functionalized areas on one substrate.