Photosensitizers Based on Zinc Phthalocyanine Derivative-Nanoparticles Assemblies

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).