Measurement of phthalocyanine binding kinetics with surface plasmon resonance method

Phthalocyanine molecules are potential candidates for the structural elements of optoelectronic devices such as organic solar cells and chemical sensors. The binding self-assembling monolayers of phthalocyanine molecules to a gold surface was studied using surface plasmon resonance (SPR) method. Reference experiments were carried out with phthalocyanines holding bromine in place of the thioacetate, therefore having no ability of covalent bonding to the gold surface. Differences in binding were evaluated and compared with simulations. Measurement results show a significant difference in dissociation speed. While molecules with triacetates decay 2 percent per hour in a stabilized dissociation state, the molecule with bromine decayed 6.5 to 10 percent per hour. Measured results were verified with simulations. These results suggest that there are at least two different binding mechanisms present.