Tunable bacterial agglutination and motility inhibition by self-assembled glyco-nanoribbons.

We explored a method of controlling bacterial motility and agglutination by using self-assembled carbohydrate-coated beta-sheet nanoribbons. To this aim, we synthesized triblock peptides that consist of a carbohydrate, a polyethylene glycol (PEG) spacer, and a beta-sheet-forming peptide. An investigation into the effect of PEG-spacer length on the self-assembly of the triblock peptides showed that the PEG should be of sufficiently length to stabilize the beta-sheet nanoribbon structure. It was found that the stabilization of the nanoribbon led to stronger activity in bacterial motility inhibition and agglutination, thus suggesting that antibacterial activity can be controlled by the stabilization strategy. Furthermore, another level of control over bacterial motility and agglutination was attained by co-assembly of bacteria-specific and -nonspecific supramolecular building blocks. The nanoribbon specifically detected bacteria after the encapsulation of a fluorescent probe. Moreover, the detection sensitivity was enhanced by the formation of bacterial clusters. All these results suggest that the carbohydrate-coated beta-sheet nanoribbons can be developed as promising agents for pathogen capture, inactivation, and detection, and that the activity can be controlled at will.