Light scattering enhancement in an aqueous solution of spermine-induced fractal J-Aggregate composite

We performed an experimental investigation on the scattering and extinction properties of an aqueous solution of spermine-induced fractal J aggregates, constituted by porphyrin molecules. In analogy with nanostructured particle composites, the dipolar moments of different porphyrins, not belonging to the J aggregates, are coupled and generate a strong light scattering enhancement. Both the enhanced scattered intensity and the imaginary part of the polarizability of the system obey scaling laws with the optical spectral dimension d0=0.3.