Self-Assembled Nanodot Actuator with Changeable Fluorescence by π-π Stacking Force Based on a Four-Armed Foldable Phthalocyanine Molecule and Its Supersensitive Molecular Recognition.

Abstract

Designing intelligent molecules and smart nanomaterials as molecular machines is becoming increasingly important in the nanoscience fields. Herein, we report a nanodot actuator with changeable fluorescence by π-π stacking force based on a four-armed foldable phthalocyanine molecule. The assembled nanodot possessed a three-dimensional molecular space structure and multiple supramolecular interactions. The arms of the nanodot could fold and open intelligently in response to environmental molecular stimuli such as natural plant mimosa, which could lead to multiple variable fluorescence emissions. The nanodot was highly sensitive to the biomolecule thyroxine at the molecular level. The accurate molecular recognition and the changeable fluorescence conversion of the nanodot were attributed to multiple supramolecular interactions, including photoinduced electron transfer (PET), intramolecular fluorescence resonance energy transfer (FRET), and π-π stacking of the nanodots, resulting in an intelligent "nanodot machine with folding arms". The self-assembled nanodot actuators with changeable fluorescence have potential applications in advanced intelligent material fields.