Bacterial infectious diseases, especially those caused by Gram-positive bacteria, have been seriously threatening human health. Preparation of a multifunctional system bearing both rapid bacterial differentiation and effective antibacterial effects is highly in demand, but remains a severe challenge. Herein, we rationally designed and successfully developed a sequence of aggregation-induced emission luminogens (AIEgens) with orderly enhanced D–A strength. Evaluation of structure–function relationships reveals that AIEgens having intrinsic positive charge and proper ClogP value are able to stain Gram-positive bacteria. Meanwhile, one of the presented AIEgens (TTPy) can generate reactive oxygen species (ROS) in extraordinarily high efficiency under white light irradiation due to the smaller singlet–triplet energy gap. Thanks to the NIR emission, excellent specificity to Gram-positive bacteria, and effective ROS generation efficiency, TTPy has been proved to perform well in selective photodynamic killing of Gram-positive bacteria in vitro, such as S. aureus and S. epidermidis, even in S. aureus-infected rat wounds.

Aiming to achieve versatile phototheranostics with the integrated functionalities of multiple diagnostic imaging and synergistic therapy, the optimum use of dissipated energy through both radiative and nonradiative pathways is definitely appealing, yet a significantly challenging task. To the best of the knowledge, there have been no previous reports on a single molecular species effective at affording all phototheranostic modalities including fluorescence imaging (FLI), photoacoustic imaging (PAI), photothermal imaging (PTI), photodynamic therapy (PDT), and photothermal therapy (PTT). Herein, a simple and highly powerful one‐for‐all phototheranostics based on aggregation‐induced emission (AIE)‐active fluorophores is tactfully designed and constructed. Thanks to its strong electron donor–acceptor interaction and finely modulated intramolecular motion, the AIE fluorophore‐based nanoparticles simultaneously exhibit bright near‐infrared II (NIR‐II) fluorescence emission, efficient reactive oxygen species generation, and high photothermal conversion efficiency upon NIR irradiation, indicating the actualization of a balance between radiative and nonradiative energy dissipations. Furthermore, the unprecedented performance on NIR‐II FLI‐PAI‐PTI trimodal‐imaging‐guided PDT–PTT synergistic therapy is demonstrated by the precise tumor diagnosis and complete tumor elimination outcomes. This study thus brings a new insight into the development of superior versatile phototheranostics for practical cancer theranostics.

The first water-soluble NIR AIEgen was synthesized and used for ultrafast wash-free cellular imaging and photodynamic cancer cell ablation.

Fluorescence imaging in the second near‐infrared (NIR‐II) window facilitated by aggregation‐induced emission luminogens (AIEgens) is an emerging research field. NIR‐II AIEgens overcome limitations imposed by penetration depth and fluorescence efficiency, offering high‐performance imaging with enhanced precision. Some reported NIR‐II AIEgens demonstrate capabilities for fluorescence and photoacoustic bimodal imaging, and fluorescence imaging guided photothermal therapy, which not only improves diagnosis accuracy but provides an efficient theranostic platform to accelerate preclinical translation as well. This minireview summarizes recent efforts on exploiting NIR‐II AIEgens with regard to molecular design strategies and bioapplications, and puts forward current challenges and promising prospects. This timely sketch should benefit the further exploitation of diverse and multifunctional NIR‐II AIEgens for a wide array of applications.