State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
J Am Chem Soc. 2019 Aug 14;141(32):12697-12706. doi: 10.1021/jacs.9b05329. Epub 2019 Aug 5.
Aggregation-induced emission (AIE) was intensively studied because of packing of small molecules and polymers; however, mid-molecular-weight (1000-3000) molecular scaffold containing a precise number of AIE luminogens is rare. Herein, we report the investigation of three tetraphenylethylene (TPE)-modified sulfono-γ-AApeptides in which multiple TPE moieties are conjugated to the chiral right-handed helical peptidomimetic backbone as functional side chains. The crystal structure of the TPE-α/sulfono-γ-AA peptide demonstrates that because of the rigid helical scaffold of the TPE-α/sulfono-γ-AA peptides, the intramolecular rotations of the TPE with short linker are restricted, therefore leading to the boosted fluorescent emission in solution. Peptides and exhibit aggregation-induced emission enhancement (AIEE), possibly because of the combination of both AIE and rotation restriction. Moreover, because of their preoriented assembly induced by the right-handed helical scaffold, these emissive chiral luminogens show effective circularly polarized luminescence signals with high dissymmetry factor . Finally, the amphiphilic nature of TPE-α/sulfono-γ-AA peptides could enable them to penetrate the bacterial membranes and exhibit strong fluorescence. Their antimicrobial activity and labeling-free character could further augment their potential applications in both materials and biomedical sciences.
聚集诱导发光（AIE）因其小分子和聚合物的堆积而受到广泛研究；然而，含有精确数量 AIE 发光团的中分子量（1000-3000）分子支架却很少见。在此，我们报告了三种四苯乙烯（TPE）修饰的磺基-γ-AA 肽的研究，其中多个 TPE 部分连接到手性右手螺旋肽模拟物主链上作为功能侧链。TPE-α/磺基-γ-AA 肽的晶体结构表明，由于 TPE-α/磺基-γ-AA 肽的刚性螺旋支架，短连接体的 TPE 分子内旋转受到限制，因此导致溶液中荧光发射增强。肽 和 表现出聚集诱导发射增强（AIEE），可能是因为同时存在 AIE 和旋转限制。此外，由于其右手螺旋支架诱导的预定向组装，这些发射手性发光团表现出有效的圆偏振发光信号，具有高不对称因子 。最后，TPE-α/磺基-γ-AA 肽的两亲性质使其能够穿透细菌膜并表现出强荧光。它们的抗菌活性和无标记特性可以进一步增强它们在材料和生物医学科学中的潜在应用。
