Detecting Interactions between Tetraphenylporphyrin and [6,6]-Phenyl-C61-Butyric Acid Methyl Ester via Fluorescence Spectroscopy

Abstract

Porphyrins and fullerene-like nanoparticles have application in nanoelectronics and photovoltaics. In nanoelectronics, donor-acceptor compatibility and electronic coupling provide an upper limit on charge transfer efficiency. Porphyrins and fullerenes are often reported to be useful for such devices in conjunction to improve charge transfer efficiency. Many different fullerene-porphyrin constructs have been shown to interact through a supramolecular complexation reaction. In this research, the interactions between a specific fullerene/porphyrin pair, [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) and tetraphenylporphyrin (H2TPP), are studied, using fluorescence spectroscopy (EEMS) as a detection method. H2TPP has been found to have a fluorescent signature. If interactions between PCBM and H2TPP occur, the fluorescent signature of H2TPP may be quenched or enhanced. Preliminary results show that fluorescent signals at certain emission wavelengths in H2TPP are quenched upon the addition of PCBM, indicating that interactions do occur. The effect of stoichiometry on the signal has also been examined. Overall, fluorescence spectroscopy has been demonstrated as a viable method for detecting complexation interactions involving a fluorescent porphyrin.