Polyester‐tethered near‐infrared fluorophores confined in colloidal nanoparticles: Tunable and thermoresponsive aggregation and biomedical applications

Abstract

Abstract Intricate assembly of multiple molecular chromophores assisted by protein scaffolds is essential in tuning the optical absorption and energy transfer in the light‐harvesting complexes of the photosynthetic systems in nature. However, it remains a challenge to achieve such structural complexity and functionality in synthetic polymer‐chromophore systems. Here, we report a series of polyester‐tethered pyrrolopyrrole cyanine derivatives and their colloidal nanoparticles dispersed in water, which show tunable J‐ or H‐aggregation excitonic coupling and near‐infrared fluorescence by precise control of the polymer chain lengths, composition, and temperature. Moreover, the optimal fluorescence or photothermal effect of the J‐aggregate nanoparticles enables broad applications in fluorescence or photoacoustic bioimaging and phototherapy.

Keywords

• bioimaging
• colloids
• fluorescence
• polymers
• self‐assembly