Bisection of biotinylated soft spherical structures.

Biotin, a water soluble vitamin, upon conjugation with ditryptophan methyl ester affords soft spherical structures in the nanometer to micrometer range. The evolution of such morphology is ascribed to favorable interaction between biotin and tryptophan residues as suggested for high affinity biotin-avidin interaction. We report unprecedented observation that biotinylated soft spherical structures undergo bisection to reveal hemispherical capsule-like structures, in the presence of avidin. This study suggests singular approach of tuning bioinspired morphologies via natural principles of interaction and affinity. We envisage that such hemispherical capsules provide an expeditious entry into interesting soft structures which may be harnessed for potential applications.