Thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) are two highly applicable emissive processes due to their time-resolved characteristics and their ability to respond to external stimuli. They have recently been integrated for comprehensive use in some solid-state luminogens; however, there remains a lack of molecular systems that can integrate them in the solution aggregated state, which considerably limits relevant biological applications. In this study, we present a molecular design enabling aggregation-induced TADF-RTP dual emission in the solution aggregated state, relying on the coexistence of T-1-to-S-1 and T-1-to-S-0 electronic processes in push-pull structures. This dual emission feature constitutes a broad spectral band with full width at half-maximum up to 175 nm, providing the ability to select different channels for biological detection and imaging. Moreover, deoxygenation is shown to promote molecular aggregation, leading to a significantly strengthened dual emission that enables a high-contrast hypoxia probing effect. These results not only reveal new photophysical mechanisms on organic molecules but also expand the detection functionality of luminescent materials in the biological field.
Funding Agencies|National Natural Science Foundation of China [22275038]; NSFC/China [K2024-33]; State Key Laboratory of Molecular Engineering of Polymers (Fudan University) [2130011540027, NAISS 2023/5-77]; Ningbo University of Technology [2020-04600]; Swedish Research Council [2009-00971]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University [212-0136]; Olle Engkvists Stiftelse (Sweden)