Supramolecular interactions in solution and on surfaces

Supramolecular interactions are a class of interactions categorized by their non-covalent character. Examples of supramolecular interactions include van der Waals forces, pi-pi stacking, hydrogen bonding, metal-ligand coordination, electrostatic interactions, and host-guest interactions.

Host-guest interactions can be used to study and exploit the assembly of molecules into a complex. For example, cyclodextrin-based host-guest chemistry uses the cyclodextrin cavity to interact with small hydrophobic moieties, like benzene- and naphthalene derivatives. Host-guest interactions are commonly used in sensors, for instance the host-guest interaction between phenolphthalein and cyclodextrin  can be used to detect ibuprofen. By functionalizing nanoparticles with cyclodextrin, the nanoparticles can be used as a readout for cyclodextrin interactions. For example, we use cyclodextrin-functionalized nanoparticles for highly sensitive enzyme detection, and for the detection of proteins (e.g., lectins) in solution.

Microcontact printing (µCP) is a versatile soft lithographic technique that can be used to ‘print’ (bio)molecules with a pattern on the surface of a substrate (such as glass, silicium, gold etc). The patterning is carried out through ‘inking’ a polydimethylsiloxane (PDMS) stamp containing the relief pattern and then ‘stamping’ the substrate with the PDMS stamp.

µCP ensures high spatial control of the surface functionalization down to the nano-scale, which allows various applications ranging from FRET sensors to flow cell applications. Current research focusses both on the formation of new functionalized surfaces and the application of these surfaces in, e.g., biomedical or catalysis applications.