Metal-triggered disassembly of Naph-Ahx-His supramolecular nanoribbons

Abstract

Self-assembly is the process where molecules in solution can spontaneously interact with one another via multiple noncovalent interactions and produce high ordered structures at the nanometer level. These structures can be further developed as functional materials in the fields of nanotechnology and engineering. In this work, we introduce a new type of amphiphilic molecule, Naph-Ahx-His, capable of self-assembling into stable nanoribbons in a buffered aqueous solution as characterized by TEM and GIXRD. The hydrophobic nature of the naphthoic ring and the 6-carbon linker coupled with the hydrophilic histidine residue, drives this molecule to initially form amorphous aggregates that reorganize into a ordered nanoribbon structures. These assemblies are crystalline in nature and stable in solution for weeks. Due to the presence of the metal chelator histidine, this molecule is able to disassemble in the presence of high concentration of copper over other divalent metal such as zinc and nickel. DFT computational studies were performed with truncated versions of the Naph-Ahx-His molecule to help explain the binding affinity preference for copper and its rapid disassembly in aqueous solution. All these findings highlight the potential of Naph-Ahx-His nanoribbons as metal-triggered nanomaterials for broader applications in metal and analyte detection.