Open Access Nano Express

Quantum dot-aluminum phthalocyanine conjugates perform photodynamic reactions to kill cancer cells via fluorescence resonance energy transfer

Lei Li1, Jin-Feng Zhao1, Nayoun Won2, Ho Jin2, Sungjee Kim2 and Ji-Yao Chen1*

Author affiliations

1 State Key Laboratory of Surface Physics, Department of Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai,, 200433, People's Republic of China

2 Department of Chemistry, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Nam-Gu, Pohang, Gyeong-Buk,, 790-784, South Korea

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Citation and License

Nanoscale Research Letters 2012, 7:386  doi:10.1186/1556-276X-7-386

Published: 12 July 2012

Abstract

Sulfonated aluminum phthalocyanines (AlPcSs), commonly used photosensitizers for photodynamic therapy of cancers (PDT), were conjugated with amine-dihydrolipoic acid-coated quantum dots (QDs) by electrostatic binding, achieving 70 AlPcSs per QD. The AlPcS-QD conjugates can utilize the intense light absorptions of conjugated QDs to indirectly excite AlPcSs producing singlet oxygen via fluorescence resonance energy transfer (FRET), demonstrating a new excitation model for PDT. The AlPcS-QD conjugates easily penetrated into human nasopharyngeal carcinoma cells and carried out the FRET in cells, with efficiency around 80%. Under the irradiation of a 532-nm laser, which is at the absorption region of QDs but not fit for the absorption of AlPcSs, the cellular AlPcS-QD conjugates can destroy most cancer cells via FRET-mediated PDT, showing the potential of this new strategy for PDT.

Keywords:
Quantum dot; Aluminum phthalocyanine; Fluorescence resonance energy transfer; Photodynamic therapy of cancers.