Authors: S. Lin, D.X. Jones, A.S. Mount and P.C. Ke
Affilation: Clemson University, United States
Pages: 238 - 241
Keywords: fullerenes, fluorescence, cells
The chemical and photophysical properties of fullerenes have been studied over the past two decades yet the biological applications of these nanoparticles remain limited. The major hurdle of integrating fullerenes with biological systems is their inherent hydrophobicity, which could be overcome by covalent or non-covalent functionalizations. Once functionalized fullerenes and their derivatives become water soluble and can potentially be used for anti-HIV, anti-oxidation, enzyme inhibition, and drug delivery. Here we present that fullerene C70 can be readily solubilized in water by gallic acid, a naturally occurring antioxidant and anti-cancer agent. The principle of this solubilization is pi-stacking between C70 and gallic acid promoted by gentle heating and probe sonication. The supramolecular complex of C70-gallic acid emits strong green fluorescence near 535 nm in aqueous solutions and in biological systems. We measured the absorbance characteristics of C70-gallic acid using a spectrophotometer and the fluorescence properties of the complex using a spectrofluorometer. We performed TEM imaging which showed small C70-gallic acid clumps of approximately 10 nm in diameter. Using confocal fluorescence microscopy we identified the uptake of C70-gallic acid by cells and living organism Daphnia. Our future studies will examine the uses of C70-gallic for drug delivery and antioxidation.