We demonstrate here the rational design strategy to control the length of 1-dimensional β-sheet peptide nanoassembly. We synthesized the β-sheet peptides with attached coils and carbohydrates. We reasoned that the bulkiness of the coils affects the final length of the assembled β-sheet peptide nanostructures because of the steric crowding effect. The nanostructure from the peptide with a small and linear coil was several micrometers long, whereas the one from the peptide with a high-volume-fraction dendritic coil was only about 150 nm long. For potential biological applications of the peptide nanoassemblies, we investigated the interactions of the carbohydrate-coated nanoassemblies with E. coli cells containing cognate binding proteins. The results showed that both of the nanoassemblies could immobilize and/or aggregate bacterial cells. The degrees of immobilization were similar for both nanoassemblies; however, only the long nanoribbon was shown to induce the formation of bacterial clusters.