Activatable second-near-infrared-window multimodal luminogens with aggregation-induced-emission and aggregation-caused-quenching properties for step-imaging guided tumor therapy.

Traditional organic luminogens, such as aggregation-caused quenching or aggregation-induced emission luminogens, only suitable to exhibit bright luminescence in the single state (i.e., solution or aggregated state), restricting their applications in heterogeneous environments. Herein, we propose a class of luminogens, aggregation-caused quenching / aggregation-induced emission dual property multimodal luminogens, which can simultaneously balance radiative and non-radiative decay processes in both the solution and aggregation states, bridging the gap between aggregation-caused quenching and aggregation-induced emission luminogens. By manipulating the rigidity planes and twisted groups of the molecules, we successfully develop a series of dual-property multimodal dyes DPM-HD1-3 with excellent second near-infrared window (NIR-II) fluorescent, photoacoustic, and photothermal properties signals. Based on the dual-property multimodal characteristics of DPM-HD3, we construct a CO-activated multimodal luminogen, DPM-HD3-CO, for the step-imaging guided therapy in the tumor-bearing mice. DPM-HD3-CO can overcome the interference of tumor heterogeneity, and reveal the relationship between CO levels and treatment response in the different treatment steps via multimodal imaging. We expect that the introduction of the concept of dual-property multimodal luminogens would open up a innovative avenue for dye chemistry, offering greater possibilities for future widespread applications in the areas such as chemistry, biomedical imaging, and energy.