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In this work, we have taken a donor–acceptor–donor (D–A–D) fluorophore ( II-EDOT-TPA ) and encapsulated it using a linear dendritic block copolymer (LDBC). In parallel, a polyethylene glycol derivative ( PEG-II-EDOT-TPA ) was synthesized. The self-assembly and colloidal properties of both nanoaggregates were comparatively assessed. Photophysical and morphological characterization of the LDBC encapsulated II-EDOT-TPA and PEG-II-EDOT-TPA nanoaggregates was performed, which showed the photophysical and morphological properties differed greatly when comparing the two. Both nanoaggregate types were incubated with HEK-293 cells in order to measure cell viability and perform confocal fluorescence microscopy. Minimal cytotoxicity values (<20%) were seen with the two nanoaggregate forms, while both types of nanoaggregates were found to accumulate into the lysosomes of the HEK-293 cells. This work provides fascinating insights into NIR fluorophore design and methods to effectively alter the photophysical and morphological properties of the nanoaggregates for bio-imaging purposes. 

A longstanding challenge in the field of optoelectronic materials, the effects of solid-state arrangement and morphology are still a prominent factor associated with small-molecule and polymer-based device performance. Here, mixed heterocyclic aromatic oligomers containing thiophene, furan and pyrazine are prepared alongside their methylated congeners. Their solution and solid-phase properties were studied via spectroscopic, electrochemical and single-crystal X-ray diffraction (XRD) analysis. Comparative analysis between solid-state packing arrangements and photophysical properties revealed optical band gaps as low as 1.7 eV with Stokes-shifts up to 130 nm and quantum yields of 12%. Results of the study aid in further understanding the effects of molecular and solid-state arrangements that give rise to unique optical and photophysical properties critical to enhancing optoelectronic behavior.