Fluorescence Quenching of Carboxy-Substituted Phthalocyanines Conjugated with Nanoparticles under High Stoichiometric Ratios

Background: The search of the approaches towards a photosensitizer’s conjugation with multifunctional nanoparticles is an important step in development photodynamic therapy techniques. Association photosensitizer molecules that perform delivery function can lead to change functional state photosensitizer. Methods: We studied effects observed upon incorporation octa- and hexadeca-carboxyphthalocyanines zinc(II) aluminum(III) (Pcs) into polymer shell semiconductor CdSe/CdS/ZnS core various spectral optical methods. Results: First, interaction Pc leads properties Pc; effect strongly depends on structure molecule (number carboxyl groups as well nature central cation macrocycle). Secondly, several molecules, concentration become significant, leading aggregation and/or nonradiative energy transfer between neighboring within single nanoparticle. Conclusions: These processes decrease number excited state. Such should be taken account during platforms for photosensitizers, including use enhancers activity by transfer.