Nano-Lithographically Directed Organization at the Molecular Scale: from Inorganic Nano-Architectures to Bio-Interfaces

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the resolution down to the molecular scale. Recently, we developed novel concepts for nanoimprint lithography based on soft mold with rigid relief features, allowing high flexibility of patterning on non-standard substrates without compromising on the pattern fidelity. We use these nanofabrication advances to produce high-resolution templates, through which we implement hybrid top-down/bottom-up approach for the nanoscale structuring of matter, as well as for the nanoscale control of molecular assemblies at bio-interfaces. In the first application, we produce templates for the controlled surface organization of CdSe-Au nanodumbbells. The templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled monolayers. Here, the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells, enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building blocks. In the second application, we functionalize the nanodot arrays with ligands for transmembrane receptors of cells, to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement of the receptors within the cell membrane. Here, efforts have been made on producing bi-functional ligand arrays that selectively control two types of receptors. These bio-chips are used to study and control the spatial cross talk between different adhesion ligands in stem cells, as well as the spatial cross-talk between the activating and inhibitory receptors in Natural Killer (NK) and T-cells.