Fabrication and Luminescence of Designer Surface Patterns with β-Cyclodextrin Functionalized Quantum Dots via Multivalent Supramolecular Coupling

Supramolecular microcontact printing was used to obtain controlled patterns consisting of quantum dots (QDs) functionalized at their periphery with P-cyclodextrin (P-CD) in combination with adamantyl terminated dendrimeric "glues". Functionalization of core-shell CdSe/ZnS QDs was achieved by surface ligation. Immobilization of the US from solution onto glass substrates printed with (a) adamantyl-terminated poly(propylene imine) dendrimers and (b),via direct microcontact printing of Us onto the dendrimer layer both yielded stable and robust multilayer structures. The stability of the patterns was primarily due to multivalent supramolecular host-guest interactions between P-CD located at the OD surface and adamantyl groups at the dendrimer periphery as the dendrimers acted as a "supramolecular glue". The surface-immobilized Us were capable of forming host-guest complexes with other molecules of interest at binding cavities not occupied by adamantyl groups. Complex formation with ferrocene-functionalized molecules at these sites led to partial quenching of the luminescence emission of QDs demonstrating the principle for sensing using the QD multilayer structures.