Carbon Nanotubes Encapsulated in Coiled‐Coil Peptide Barrels

• Published in: Chemistry : a European journal 2018-08, Vol.24 (47), p.12241-12245
• Main Authors: Mann, Florian A., Horlebein, Jan, Meyer, Nils Frederik, Meyer, Daniel, Thomas, Franziska, Kruss, Sebastian
• Format: Article
• Language: English
• Subjects: Atomic beam spectroscopy; Atomic force microscopy; Barrels; biosensors; carbon; Chemistry; coiled coil; Coils; Drug delivery; Drug delivery systems; Encapsulation; Fluorescence; Fluorescence spectroscopy; Medical imaging; Microscopy; Nanomaterials; Nanotechnology; Nanotubes; Peptides; Pores; Single wall carbon nanotubes
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201800993

Specific functionalization of 1D nanomaterials such as near infrared (nIR) fluorescent single‐walled carbon nanotubes (SWCNTs) is essential for colloidal stability and tailoring of their interactions with the environment. Here, we show that de novo designed alpha‐helical coiled‐coil peptide barrels (αHBs) with appropriate pores encapsulate and solubilize SWCNTs. In contrast, barrels without or with narrow pores showed a much smaller efficiency. Absorption/fluorescence spectroscopy and atomic force microscopy indicate that the SWCNTs are incorporated into the αHB′s pore. The resulting hybrid SWCNT@αHBs display periodic surface coverage with a 40 nm pitch and remain fluorescent in the nIR. This approach presents a novel concept to encapsulate, discriminate and functionalize SWCNTs non‐covalently with peptides and holds great promise for future applications in bioimaging or drug delivery. Rollin′, rollin′: De‐novo designed α‐helical coiled‐coil peptide barrels were used to encapsulate, solubilize and discriminate single‐walled carbon nanotubes. Different analytical techniques revealed a periodic surface‐coverage pattern. These α‐helical barrels can act as an anchoring platform for functional units around carbon nanotubes, which opens up new avenues for their application.