New Conjugates Based on AIS/ZnS Quantum Dots and Aluminum Phthalocyanine Photosensitizer: Synthesis, Properties and Some Perspectives

Abstract

Today, fluorescent diagnostics and photodynamic therapy are promising methods for diagnosing and treating oncological diseases. The development of new photosensitizers (PS) is one of the most important tasks to improve the efficiency of both laser-induced diagnostics and therapy. In our study, we conjugated PS with AIS/ZnS triple quantum dots (QDs) to obtain non-aggregated complexes. It was shown that the conjugation of PS with QDs does not change the PS fluorescence lifetime, which is a marker of the preservation of PS photophysical properties. In particular, efficient resonant Förster energy transfer (FRET), from QDs to PS molecules in the conjugate, increases the PS luminescence response. The FRET from QD to PS molecules with different ratios of donor and acceptors are shown. It has been demonstrated that the average efficiency of FRET depends on the ratio of PS and QD and reaches a maximum value of 80% at a ratio of 6 PS molecules per 1 QD molecule. Thus, these studies could help to contribute to the development of new complexes based on QD and PS to improve the efficiency of phototheranostics.

Keywords

• quantum dots
• aluminum phthalocyanine
• photosensitizer
• FRET
• photodynamic therapy
• reactive oxygen species (ROS)