From Bioconjugation to Self‐Assembly in Nanobiotechnology: Quantum Dots Trapped and Stabilized by Toroid Protein Yoctowells

Abstract Conjugation of quantum dots (QDs) with proteins is applicable for biosensing and imaging in biomedical applications but also for the confined assembly of various nanostructures. Here, the conjugation of CdSe QDs ranging from 2.5 up to 9.5 nm with Hcp1, a yoctowell forming hexameric core protein of Pseudomonas aeruginosa, is described. Defined structures ranging from single QDs trapped within the donut‐shaped hexameric protein cavity over “globular” multi‐toroid architectures up to photonic wires of 850 nm in length and 9 nm in width are self‐assembled while preserving the native hexameric structure of the protein conserving the photoluminescence intensity of the QDs in aqueous solution for more than 3 month.