Gold nanoparticles-pyrrolidinonyl metal phthalocyanine nanoconjugates: Synthesis and photophysical properties

A novel series of pyrrolidinonyl metal phthalocyanines (PyMPc, M = Zn, Cu, Co and Ni) was synthesized. Their structures were characterized by IR, H-1 NMR, ESI-MS as well as elemental analysis. The photophysical properties of PyMPcs were studied by UV/vis and fluorescence spectroscopic methods. AuNPs-MPEG-PyMPc nanoconjugates were prepared by conjugating the thiolatedmethoxypolyethylene glycol capped gold nanoparticles (AuNPs-MPEG) with PyMPc through a donor-acceptor interaction. UV/Vis spectra and TEM images evidenced that the PyMPcs were conjugated with gold nanoparticles. The photophysical properties of both free PyMPcs and AuNPs-MPEG-PyMPc nanoconjugates exhibited central ions dependence. PyZnPc and AuNPs-MPEG-PyZnPc exhibited the highest fluorescence quantum yields. But the fluorescence lifetimes of AuNPs-MPEG-PyMPc (M = Cu, Co and Ni) were longer than that of corresponding free phthalocyanines.