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

Fan Ni; Zece Zhu; Xiao Tong; Weixuan Zeng; Kebin An; Danqing Wei; Shaolong Gong; Qiang Zhao; Xiang Zhou; Chuluo Yang

doi:10.1002/advs.201801729

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

Adv Sci (Weinh). 2019 Jan 13;6(5):1801729. doi: 10.1002/advs.201801729. eCollection 2019 Mar 6.

Authors

Fan Ni^{1

2}, Zece Zhu^{1

3}, Xiao Tong⁴, Weixuan Zeng¹, Kebin An¹, Danqing Wei¹, Shaolong Gong¹, Qiang Zhao⁴, Xiang Zhou¹, Chuluo Yang^{1

2}

Affiliations

¹ Department of Chemistry and Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Wuhan University Wuhan 430072 China.
² College of Materials Science and Engineering Shenzhen University Shenzhen 518060 China.
³ Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China.
⁴ Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials Nanjing University of Posts and Telecommunications Nanjing 210023 China.

Abstract

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.

Keywords: aggregation‐induced delayed fluorescence enhancement; mitochondria‐specific imaging; thermally activated delayed fluorescence; time‐resolved luminescence imaging.