Self-assembled dendron nanotubes with a surface peptide–fluorophore conjugate as a sensory vehicle

Abstract

We report a facile approach to construct the hierarchically self-assembled dendron–cyclodextrin (CD) nanotubes with a dansyl fluorophore connected to the surface of the tube via a Gly-Gly-His (GGH) tripeptide spacer unit (Den-dans-GGH-CD-NTs) through a molecular recognition process of CDs and an amide dendron with the focal pyrene moiety. Den-dans-GGH-CD-NTs were utilized as a sensory platform for Cu(II) which can selectively bind to the GGH unit on the nanotube. Upon addition of Cu(II) into the tubular solution of Den-dans-GGH-CD-NTs, the fluorescence quenching of the dansyl fluorophore was observed due to photo-induced electron transfer to copper ions. A quantitative analysis showed that the detection limit for copper(II) ions was 148 nM. Furthermore, the Den-dans-GGH-CD-NT platform can be reused by abstraction of Cu(II) from the GGH unit with retaining the sensory capability.