abstract
The present study describes the first example of hybrid particles composed of amorphous silica and corrole. The hybrid particles were obtained by covalent linking of the gallium(III)(pyridine) complex of 5,10,15-tris(pentafluorophenyl) corrole (GaPFC) at the surface of functionalized silica spheres. The functionalization step was achieved by a nucleophilic substitution reaction between corrole and 3-aminopropyltriethoxysilane previously grafted at the silica surfaces. The hybrids were morphologically and chemically characterized and the results have confirmed covalent linkages between corrole molecules and the silica particles. Preliminary studies on the capacity of corrole and hybrid particles to generate singlet oxygen was evaluated by a chemical method in which 1,3-diphenylisobenzofuran was used to trap singlet oxygen. The new corrole-silica hybrid particles have shown lower efficiency to generate singlet oxygen as compared to the pure corrole precursor. This effect was interpreted as a consequence of interparticle interactions mediated by the corrole molecules grafted at the silica surfaces that result in their clustering. Taken together, these findings demonstrate that despite lower efficiency in terms of singlet oxygen generation, the hybrid materials offer an alternative route to develop new platforms with potential for photodynamic therapy.
keywords
RAY PHOTOELECTRON-SPECTROSCOPY; PHOTODYNAMIC THERAPY; NANOPARTICLES; PORPHYRINS; SURFACE; FILMS
subject category
Chemistry
authors
Barata, JFB; Daniel-Da-Silva, AL; Neves, MGPMS; Cavaleiro, JAS; Trindade, T
our authors
Ana Luísa Daniel da Silva
Principal Researcher
Joana Filipa Brites Barata
Post-doc Fellowship
Tito Trindade
Full professoracknowledgements
Thanks are due to Fundacao para a Ciencia e a Tecnologia (FCT)), FSE and POPH for funding the Organic Chemistry Research Unit (Pest-C/QUI/UI0062/2011) and CICECO (Pest-C/CTM/LA0011/2011). J. F. B. Barata thanks FCT for the grant SFRH/BPD/63237/2009. We thank the RNME (National Electronic Microscopy Network) for SEM images.