Azobenzene, while relevant, has faced constraints in biological system applications due to its suboptimal quantum yield and short-wavelength emission. This study presents a pioneering strategy for fabricating organic microdots by coupling foldamer-linked azobenzene, resulting in robust fluorescence intensity and stability, especially in aggregated states, thereby showing promise for bioimaging applications. Comprehensive experimental and computational examinations elucidate the mechanisms underpinning enhanced photostability and fluorescence efficacy. In vitro and in vivo evaluations disclose that the external layer of cis-azo-foldamer microdots performs a self-sacrificial function during photo-bleaching. Consequently, these red-fluorescent microdots demonstrate extraordinary structural and photochemical stabilities over extended periods. The conjugation of a β-peptide foldamer to the azobenzene chromophore through a glycine linker instigates a blue-shifted and amplified π^*–n transition. Molecular dynamics simulations reveal that the aggregated state of cis-azo-foldamers fortifies the stability of cis isomers, thereby augmenting fluorescence efficiency. This investigation furnishes crucial insights into conceptualizing novel, biologically inspired materials, promising stable and enduring imaging applications, and carries implications for diverse arenas such as medical diagnostics, drug delivery, and sensing technologies.

中文翻译：

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有机微粒的红色荧光：利用折叠体连接的偶氮苯增强生物成像应用中的稳定性和强度


偶氮苯虽然相关，但由于其次优的量子产率和短波长发射而在生物系统应用中面临限制。这项研究提出了一种通过耦合折叠体连接的偶氮苯来制造有机微粒的开创性策略，从而产生强大的荧光强度和稳定性，特别是在聚集状态下，从而显示出生物成像应用的前景。综合实验和计算检查阐明了增强光稳定性和荧光功效的机制。体外和体内评估表明，顺式偶氮折叠体微粒的外层在光漂白过程中发挥自我牺牲功能。因此，这些红色荧光微粒在较长时间内表现出非凡的结构和光化学稳定性。 β-肽折叠体通过甘氨酸连接体与偶氮苯发色团的缀合引发蓝移和放大的 π ^* -n 跃迁。分子动力学模拟表明，顺式偶氮折叠体的聚集状态增强了顺式异构体的稳定性，从而提高了荧光效率。这项研究为概念化新颖的、受生物启发的材料、有前途的稳定和持久的成像应用提供了重要的见解，并对医疗诊断、药物输送和传感技术等不同领域产生了影响。