Photo‑induced Interfacial Electron Transfer of ZnO Nanocrystals to Control Supramolecular Assembly in Water

Anna Maria Cieślak,^a Emma-Rose Janecek,^b Kamil Sokołowski,^a Tomasz Ratajczyk,^a Michał Krzysztof Leszczyński,^a Oren A. Scherman,^b Janusz Lewiński^ac

^a Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
^b Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
^c Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland

DOI: 10.1039/C7NR03095A.
First published online 22 Sep 2017.
Paper at Publisher's website

Herein, we show how the inherent light‑induced redox properties of semiconducting nanocrystals (NCs) can be utilized for the photo-driven reversible modulation of dynamic supramolecular systems formed at their interfaces that, on their own, do not respond to light. This was achieved by the unprecedented combination of photoactive zinc oxide NCs (ZnO NCs) with host‑guest chemistry of cucurbit[8]uril (CB[8]) providing a route to semiconductor-assisted light‑modulation of supramolecular assemblies (SALSA), here mediated by photo‑generation of viologen radical cations (MV+•) at the NC corona and their further dimerization enhanced by CB[8] macrocycles. The reported SALSA strategy was successfully applied for light‑controlled reversible assembly processes at NCs interfaces enabling light‑triggered release of guest molecules from surface confined discrete CB[8] host‑guest complexes.

We acknowledge the National Science Centre, Poland for the support within the Preludium 2015/17/N/ST5/03333 (A. Cieślak), and OPUS (J. Lewinski) projects.