Photosensitizers Based on Zinc Phthalocyanine Derivative-Nanoparticles Assemblies

Abstract

This paper reports the conjugation of (MeIt)₈ZnPcCl₈ to silver nanoparticles (AgNPs) through a metal−ligand coordination system. From the spectral and photophysical studies, the Stokes shift, the excited state lifetime, and the quantum yield are estimated. It was observed that the conjugation of (MeIt)₈ZnPcCl₈ to AgNPs in DMSO/H₂O solution led to an increase in the absorption intensity of the Q band with a maximum at 675 nm and a shift of it of 10 nm. The fluorescence intensity of the (MeIt)₈ZnPcCl₈ is significantly higher than values obtained for (MeIt)₈ZnPcCl₈:AgNP compounds. The presence of AgNPs results in an increase in both triplet quantum yields and lifetimes, which is an advantage in the efficient generation of singlet oxygen quantum yields. The triplet quantum yield of 15.10% for (MeIt)₈ZnPcCl₈ conjugated to AgNP in DMSO/H₂O was obtained (compared to 0.1% for the non-conjugated compound).