Boronic ester-functionalized dual-state emitter for oxygen/strain sensing and dynamic encryption

A novel luminogen named BTDA-BA was designed and synthesized, presenting simultaneously long-lived room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) emissions in the glassy DMSO solution, rigid PMMA (polymethyl methacrylate) and PVA (polyvinyl alcohol), flexible PVC (polyvinyl chloride) and SIS (styrene-isoprene-styrene block copolymer) matrices. Noteworthy, RTP and TADF lifetimes of 1 % BTDA-BA@PVA film are up to 1307.28 ms and 566.55 ms in turn. Comparing four different doping matrices, BTDA-BA shows the best oxygen detection ability in PVC (λ_em = 505 nm, λ_ex = 365 nm), with high sensitivity to oxygen concentration changes, excellent reversibility, and good linear correlation between RTP intensity and oxygen concentration, whose detection range and K_SV are 0-2.1 × 10⁵ ppm and 1.96 × 10^-5 ppm^-1, respectively. Besides, 1 % BTDA-BA@PVC film exhibits excellent strain-detection properties. By constructing ternary doping systems and utilizing Förster resonance energy transfer (FRET), long-lived orange afterglow is achieved. This work develops a novel dual-state long afterglow material, achieves persistent luminescence in both rigid and flexible matrices, and realizes efficient oxygen and strain detection, flexible displays, 3D modeling, and complex dynamic information encryption, which will contribute to boosting practical and theoretical advancements of multifunctional long afterglow materials.