PHOTOPHYSICAL BEHAVIOR OF FLUORESCENT NANOCOMPOSITES OF PHTHALOCYANINE LINKED TO QUANTUM DOTS AND MAGNETIC NANOPARTICLES

Fluorescent nanocomposite that consists of 3-aminopropyltriethoxysilane coated magnetic iron nanoparticles (MN), mercaptopropionic acid capped CdTe quantum dots (QD) and octacarboxy metallophthalocyanine (MOCPc) with either aluminium ((OH)AlOCPc) or zinc (ZnOCPc) as central metals have been prepared with (linked MOCPc-QD-MN) and without (mixed MOCPc-QD-MN) linking agents. The results presented give evidence of linkage within the components of the linked MOCPc-QD-MN. A red shift in the emission peak of QD within the linked nanocomposite compared to emission peak of QD alone was observed. Photoexcitation of both linked and mixed MOCPc-QD-MN at the excitation wavelength of the QD resulted in energy transfer from QD to the respective MOCPc while at the excitation wavelength of the MOCPc, a shift in emission peak of the linked MOCPc-QD-MN was observed resulting in large Stokes' shifts. The linked and mixed MOCPc-QD-MN were found to exhibit high triplet state quantum yields compared to the MOCPcs alone.