Abstract
By adopting structural conformations with sub-nanometer precision, nature creates highly concentrated pigment-protein arrays to capture solar energy with high-efficiency. Synthetic analogues of such systems exhibit concentration dependent fluorescence quenching when approaching pigment concentrations of that seen in biological systems. Here we report on systems of acid functionalised multi-walled carbon nanotubes (o-MWCNT) and aminophenyl tetraporphyrins that create a novel synthetic pigment-scaffold complex. The complex does not follow the trend of typical fluorescence quenching. Our steady-state and time-resolved data suggest an optimal concentration that offers a luminescence enhancement compared to the expected standard Stern-Volmer quenching relationship. The quenching is modified by controlling 1 the pigment-distance via agglomerate size to near the upper limit for Dex-ter transfer of 10Å10˚10Å as confirmed by dynamic light scattering measurements and chromophore-chromophore nearest neighbour calculations. Our results highlight a potential synthetic complex with facile synthesis to investigate resonant electron transfer processes that do not follow traditional luminescence self-quenching relationships.