Selectively Lighting Up Singlet Oxygen via Aggregation-Induced Electrochemiluminescence Energy Transfer.

Xuwen Gao, Huimin Zhao, Dongyang Wang, Yuqi Xu, Bin Zhang, Guizheng Zou

Analytical chemistry 2022 Mar 01

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Singlet oxygen (1O2) is an important reactive oxygen species (ROS) that is intensively involved in natural photochemical and photobiological processes. Herein, selectively lighting up 1O2 is achieved in the aggregation-induced emission (AIE) of electrochemiluminescence (ECL) from the Zn2+-mediated AIE assembly of Au nanoclusters (Zn2+-AIE-AuNCs). Zn2+-AIE-AuNCs can exhibit efficient AIE ECL and photoluminescence (PL) along with 1O2 generation in energy and charge transfer routes, respectively. The AIE ECL of the Zn2+-AIE-AuNCs/tripropylamine (TEA) system in carbonate buffer is located around 703 nm with the dimeric aggregate of 1O2 as an emitter because electrochemically oxidizing coexisted Zn2+-AIE-AuNCs and TEA in carbonate buffer would promote the oxygen vacancy (Ov) of Zn2+-AIE-AuNCs, which could selectively enable the generation of emissive singlet oxygen in the energy transfer route by effectively transferring the energy from excited singlet Zn2+-AIE-AuNCs to the triplet ground state of dissolved oxygen (3O2). No emissive 1O2 is detected via electrochemically oxidizing the Zn2+-AIE-AuNCs in the case without either carbonate buffer or TEA, and the Zn2+-AIE-AuNCs/TEA system can only exhibit AIE ECL around 485 nm with Zn2+-AIE-AuNCs as the emitter in carbonate-free buffers. Photoexciting Zn2+-AIE-AuNCs merely brings out band-gap-engineered AIE PL around ∼485 nm with Zn2+-AIE-AuNCs as the emitter, which manifests that the 1O2 generated in the charge transfer route via photoexciting Zn2+-AIE-AuNCs is un-emissive. This work not only proposes an effective strategy for AIE with 1O2 as an emitter but also opens a promising way to selectively light up 1O2.

Citation

Xuwen Gao, Huimin Zhao, Dongyang Wang, Yuqi Xu, Bin Zhang, Guizheng Zou. Selectively Lighting Up Singlet Oxygen via Aggregation-Induced Electrochemiluminescence Energy Transfer. Analytical chemistry. 2022 Mar 01;94(8):3718-3726