A Eu(III) Supramolecular Emissive Label for Cyclodextrin‐Based (Nano)Materials

The determination of the biodistribution of cyclodextrin‐based (nano)materials represents a critical point for their development and in vivo use as drug carriers and gene‐delivery systems. In this work, we report the design and preparation of a Eu(III)‐based emissive probe based on a new adamantyl‐appended β ‐diketone. This probe has favorable emission and structural features, as it is endowed with a long lifetime (280 µs). Also, it is able to form a stable supramolecular inclusion complex with virtually any cyclodextrin‐based systems. With such an emissive probe, time‐resolved fluorescence imaging techniques could be exploited to obtain images with higher contrast and hence enhanced quality, allowing one to follow the fate of cyclodextrin‐based delivery systems in complex biological media, such as cells and tissues.