Fullerenols Revisited: Highly Monodispersed Photoluminescent Nanomaterials as Ideal Building Blocks for Supramolecular Chemistry.

Fullerenols have been known for decades; however, the photoluminescent (PL) properties and applications in supramolecular chemistry of these molecules have not been well addressed. Herein, a strategy has been developed to purify the as-prepared fullerenols, and the photoluminescence and capabilities of these molecules to form supramolecular self-assemblies were systematically studied. It was found that fullerenols show wavelength-dependent emission with an absolute fluorescent quantum yield of approximately 3.5 %. The PL characteristics are reminiscent of carbon dots, especially those obtained by using the top-down method. The studied fullerenols can be used to detect Cu2+ ions with a limit of detection down to 3.50 μm. In addition, the amphiphilicity of the fullerenols can be readily tuned by ionic complexation with cationic surfactants, such as 1-tetradecyl-3-methylimidazoliumbromide (C14 mimB) and tetradecyltrimethylammonium bromide (TTAB). On increasing the concentration of the surfactant, the transition of aggregates was induced from highly ordered vesicles to honeycomb-structured crystals and finally to giant micelles. After the formation of supramolecular self-assemblies, enhancement of photoluminescence was observed, which can be ascribed to the suppression of intramolecular vibrations and motion combined with the loosely packed self-assembly array. This study provides a facile way to generate PL nanoarchitectures, which may find applications in fluorescent sensing, drug delivery, and optoelectronics.