Optical Enhancement and Structural Properties of a Hybrid Organic-Inorganic Ternary Nanocomposite

The assembly among gold nanoparticles, the water-soluble tetrakis(4-sulfonatophenyl)porphyrin and spermine, in acidic solution, forms a hybrid nanocomposite exhibiting scattering enhancement. A scaling law of a cluster-cluster aggregate of metal nanoparticle composites, with 0.3 as optical spectral dimension, is observed in agreement with theoretical models. In this ternary composite, spermine acts as a sticky agent for gold nanoparticles and porphyrins, and the dipolar coupling between porphyrins is responsible for the localization of the electric field giving rise to the scattering enhancement.