A fluorescent polymeric quantum dot/aptamer superstructure and its application for imaging of cancer cells.

In this work, a novel polymeric quantum dot/aptamer superstructure with a highly intense fluorescence was fabricated by a molecular engineering strategy and successfully applied to fluorescence imaging of cancer cells. The polymeric superstructure, which is composed of both multiple cell-based aptamers and a high ratio of quantum dot (QD)-labeled DNA, exploits the target recognition capability of the aptamer, an enhanced cell internalization through multivalent effects, and cellular disruption by the polymeric conjugate. Importantly, the polymeric superstructure exhibits an increasingly enhanced fluorescence with recording time and is thus suitable for long-term fluorescent cellular imaging. The unique and excellent fluorescence property of the QD superstructure paves the way for developing polymeric QD superstructures that hold promise for applications such as in vivo imaging.