Stepwise Energy Transfer: Near-Infrared Persistent Luminescence from Doped Polymeric Systems
Stepwise Energy Transfer: Near-Infrared Persistent Luminescence from Doped Polymeric Systems
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逐步能量转移：掺杂聚合物系统的近红外持续发光
DOI：
10.1002/adma.202108333
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发表时间：
2022-03-03
影响因子：
29.4
通讯作者：
Chi, Zhenguo
中科院分区：
文献类型：
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作者：
Lin, Faxu;Wang, Haiyang;Chi, Zhenguo
有机近红外(NIR)长寿命发光体系在通信、成像、传感器等领域具有重要的应用价值。然而，实现这些材料(特别是寿命超过0.1%的S)是一个挑战，主要是因为它们的长寿命激子的非辐射猝灭。基于一种新型的三苯基染料掺杂聚合物(三苯基-2-基硼酸/聚乙烯醇(TP@PVA))，提出了一种适用于具有显著持久发光(在810 nm处达到0.2FRET)的明亮近红外体系的分步Forster共振能量转移(FRET)的通用策略。这种持久的近红外发光不仅被应用于近红外防伪，而且被应用于穿透厚度为2.0 mm的皮肤的近红外生物成像。通过将一种红色染料(如尼罗红)和一种近红外染料花菁7(Cy7)共同掺杂到掺杂的PVA薄膜中，通过从TP到中间红染料再到单线到单线(SS)-FRET再到Cy7的逐步FRET过程，成功地解决了TP发射和Cy7吸收之间光谱重叠的不足。值得注意的是，较低的SS-FRET显著提高了较高的TS-FRET的效率，从而导致了连续FRET的高效率。
Organic near infrared (NIR) persistent-luminescence systems with bright and long-lived emission are highly valuable for applications in communication, imaging, and sensors. However, realizing these materials (especially lifetime over 0.1 s) is a challenge, mainly because of non-radiative quenching of their long-lived excitons. Herein, a universal strategy of stepwise Forster resonance energy transfer (FRET) for a bright NIR system with remarkable persistent luminescence (up to 0.2 s at 810 nm) is presented, based on a new triphenylene-dye-doped polymer (triphenylene-2-ylboronic acid@poly(vinyl alcohol) (TP@PVA)) with a persistent blue phosphorescence of 3.29 s. This persistent NIR luminescence is demonstrated for application not only in NIR anti-counterfeiting but also NIR bioimaging with penetrating a piece of skin as thick as 2.0 mm. By co-doping a red dye (such as Nile red) and an NIR dye Cyanine 7 (Cy7) into this doped PVA film, the shortage of spectral overlap between TP emission and Cy7 absorbance is successfully solved, through a stepwise FRET process involving triplet to singlet (TS)-FRET from TP to the intermediate red dye and then singlet to singlet (SS)-FRET to Cy7. It is noted that the efficiency of the upper TS-FRET is enhanced significantly by the lower SS-FRET, leading to high efficiencies for the continuous FRETs.