Hydrophilic, Red‐Emitting, and Thermally Activated Delayed Fluorescence Emitter for Time‐Resolved Luminescence Imaging by Mitochondrion‐Induced Aggregation in Living Cells

• Published in: Advanced science Vol. 6; no. 5; pp. 1801729 - n/a
• Main Authors: Ni, Fan, Zhu, Zece, Tong, Xiao, Zeng, Weixuan, An, Kebin, Wei, Danqing, Gong, Shaolong, Zhao, Qiang, Zhou, Xiang, Yang, Chuluo
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 06.03.2019; John Wiley and Sons Inc
• Subjects: aggregation‐induced delayed fluorescence enhancement; Design; Mitochondria; mitochondria‐specific imaging; thermally activated delayed fluorescence; time‐resolved luminescence imaging; aggregation‐induced delayed fluorescence enhancement; thermally activated delayed fluorescence; time‐resolved luminescence imaging; mitochondria‐specific imaging
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.201801729

Thermally activated delayed fluorescence (TADF) materials have provided new strategies for time‐resolved luminescence imaging (TRLI); however, the development of hydrophilic TADF luminophores for specific imaging in cells remains a substantial challenge. In this study, a mitochondria‐induced aggregation strategy for TRLI is proposed with the design and utilization of the hydrophilic TADF luminophore ((10‐(1,3‐dioxo‐2‐phenyl‐2,3‐dihydro‐1H‐benzo[de]isoquinolin‐6‐yl)‐9,9‐dimethyl‐9,10‐dihydroacridin‐2‐yl)methyl)triphenylphosphonium bromide (NID‐TPP). Using a nonconjugated linker to introduce a triphenylphosphonium (TPP+) group into the 6‐(9,9‐dimethylacridin‐10(9H)‐yl)‐2‐phenyl‐1H‐benzo[de]isoquinoline‐1,3(2H)‐dione (NID) TADF luminophore preserves the TADF emission of NID‐TPP. NID‐TPP shows clear aggregation‐induced delayed fluorescence enhancement behavior, which provides a practical strategy for long‐lived delayed fluorescence emission in an oxygen‐containing environment. Finally, the designed mitochondrion‐targeting TPP+ group in NID‐TPP induces the adequate accumulation of NID‐TPP and results in the first reported TADF‐based time‐resolved luminescence imaging and two‐photon imaging of mitochondria in living cells. A hydrophilic, red‐emitting emitter NID‐TPP is constructed by using a nonconjugated linker to introduce a triphenylphosphonium group into the hydrophobic thermally activated delayed fluorescence emitter 6‐(9,9‐dimethylacridin‐10(9H)‐yl)‐2‐phenyl‐1H‐benzo[de]isoquinoline‐1,3(2H)‐dione (NID). ((10‐(1,3‐dioxo‐2‐phenyl‐2,3‐dihydro‐1H‐benzo[de]isoquinolin‐6‐yl)‐9,9‐dimethyl‐9,10‐dihydroacridin‐2‐yl)methyl)triphenylphosphonium bromide (NID‐TPP) demonstrates obvious aggregation‐induced delayed fluorescence enhancement behavior, and its application for specific time‐resolved luminescence imaging by mitochondria‐induced aggregation in living cells is conducted.