The large choice of surface modifications that can be applied to the chemically active surface templates generates a plethora of functionalization schemes that include either the chemical modification of the template, and/or the self-assembly of valuable precursors to widen the scope of applicable surface reactions, as well as the self-assembly of nanoparticles and molecules by making use of covalent and non-covalent interactions.
In a recent study, researchers from the Eindhoven University of Technology reported in Nanotechnology the use of chemically active surface templates fabricated by electro-chemical lithography of an inert self-assembled monolayer of n-octadecyltrichlorosilane to generate a platform to implement the widely used click-chemistry approach on a 50 nm wide surface pattern.
In particular, this versatile functionalization process allows for the attachment of virtually any molecule that is facilitated with an acetylene group and can potentially span the entire range of functional materials. Therefore, this important modification scheme was implemented onto the tip-mediated electro-oxidation process. The exclusive self-assembly of an 11-bromoundecyltrichlorosilane precursor on the chemically activated surface structures was subsequently converted into azide functions. These moieties were used as host structures where the acetylene functionalized materials could be covalently linked to the structures via the 1,3-dipolar cycloaddition reaction.
This highly efficient modification strategy offers a number of advantages and possibilities in terms of nanofabrication. These include the high degree of functionalization of the surface modification, the mild reaction conditions, the choice of readily available molecules that can be simply clicked onto the nanometric templates, stereoselectivity of the reaction, and the wide range of applicable solvents, including water.