A dual-twisted molecular strategy achieves dramatic quantum-yield enhancement in NIR-II AIEgen for high-performance bioimaging

Developing NIR-II AIEgens with high fluorescence efficiency offers significant potential to revolutionize disease diagnosis and monitoring. However, existing designs largely rely on twisted donor–acceptor, donor–π-bridge, or acceptor–π-bridge motifs. Although twisted dual-acceptor architectures provide a fresh paradigm, reliance on a single twisted component has limited structural diversity and capped performance gains, necessitating innovative design philosophy. Here, we introduce a dual-twisted strategy that integrates two distinct types of twisted elements, namely a twisted dual-acceptor and a distorted acceptor–π bridge, within a single fluorophore. Compared with its single-twist analogue, the dual-twisted 2TT-o2BBTD exhibits not only an enhanced AIE effect but also a remarkable improvement in relative quantum yields (QY). Specifically, its relative QY is 7.6 times higher in solution and 27.5 times higher in the aggregate state than that of the control molecule. Mechanistic studies reveal that the dual-twisted design strengthens intermolecular interactions, mitigates intramolecular motions, and weakens nonradiative decay, thereby drastically boosting fluorescence emission. Leveraging these advantages, 2TT-o2BBTD NPs enable high-quality visualization of whole-body vasculature, the mesenteric system, tumor resection process, and cerebrovascular network. Collectively, this work presents the first evidence that the dual-twisted tactic could serve as a new design direction for the AIE development, delivering stronger packing, superior AIE effect, and improved bioimaging performance.