Achieving redox-responsive organic afterglow materials via a dopant–matrix design strategy

Abstract

When compared to their fluorescence counterparts, stimuli-responsive organic afterglow materials exhibit distinct advantages to function normally even in the presence of strong background fluorescence. However, the types of these afterglow...

TADF-Type Organic Afterglow Nanoparticles with Temperature and Oxygen Dual-Responsive Property for Bimodal Sensing

“…The absence of ambient afterglow in difluoroboron β-diketonate (BF 2 bdk) systems is trivial. 35,39,58,62 Our previous study has demonstrated that a suitable organic matrix (the second component) can assist the population of triplet excited states of luminescent dopants and protect dopants' organic triplets, leading to the emergence of significant ambient afterglow in the two-component system. 54,64 Here, we apply a two-component strategy and emulsion polymerization for the preparation of TADF-type organic afterglow nanoparticles.…”

“…Pioneering studies demonstrated that oxygen, mechanical force, temperature, and light can induce a change in the photophysical properties of room-temperature phosphorescence and organic afterglow materials. − The reported studies in recent years exhibited that acid (or base), metal ion, and specific chemicals can also trigger a photophysical change in organic afterglow systems either by rational molecular design or by serendipitous finding. − For instance, solid-state crown ethers have been reported to recognize specific ions, leading to afterglow enhancement under ambient conditions . Diels–Alder reaction between phosphorescence emitters and external chemicals has been shown to give a significant afterglow change at room temperature .…”

“…A recent study in our group also exhibited that redox-responsive afterglow materials can make invisible oxidation events visible to human eyes by afterglow response. 35 There has been significant progress in the field in recent years, and it has been found that most responsive afterglow systems can only respond to single stimulus, with dual-and multiresponsive afterglow materials being less reported. 38−40 Dual-responsive afterglow materials in aqueous medium remain rarely reported.…”

“…Long-lived excited-state property represents one of the defining features of room-temperature phosphorescence and organic afterglow materials, − which can avoid interference from background fluorescence and show application in optical sensing and analysis, bioimaging, anticounterfeiting, and data encryption. − Among these materials, stimuli-responsive afterglow materials have received tremendous research interest because they can function normally even in the presence of a very strong fluorescence background. − Background fluorescence usually possesses an emission lifetime of nanoseconds. In the time-gated mode (for example, 1 ms delay or 10 ms delay), fluorescence background with nanosecond lifetime would disappear, and consequently, only the afterglow emission signals of stimuli-responsive afterglow materials can be recorded.…”

Water-soluble polymers with aggregation-induced emission and ultra-long room temperature phosphorescence

“…[22][23][24] Therefore, design-ing long-lived room temperature phosphorescence (RTP) materials is challenging. In recent years, many strategies have been developed to promote the effective emission of organic phosphorescence, which includes the following two key points: (1) improvement of the intersystem crossing (ISC) efficiency from the lowest excited singlet state (S 1 ) to the excited triplet (T n ) or from the lowest excited triplet (T 1 ) to the ground state (S 0 ), which can be achieved effectively by enhancing the spin-orbit coupling or by reducing the energy gap between the singlet and triplet states; [25][26][27] (2) inhibition of the nonradiative transition process from the lowest excited triplet state to the ground state as much as possible as the active triplet excitons are often quenched by oxygen, solvent, and high temperature. This is generally achieved by introducing microscopic rigid structures and constructing strong interactions.…”