Self-Assembled Nanostructures Of Peptide Modified Naphthalene Diimide And Its Mechanism

With the deeply molecular self-assembly research has been carried out,new materials which are composed of molecular self-assembly have been widely used in various fields.The self-assembly of polypeptide molecules has attracted considerable amount of attention recently owing to the excellent biocompatibility of peptide molecules and the versatile design of molecular structures.Short peptide molecules are more and more concerned because of their simple synthesis and simple structure.In addition,the introduction of some functional hydrophobic groups not only provides the necessary driving force for self-assembly and promotes the self-assembly,but also further broaden the scope of application.Five tripeptide sequences with high aggregation tendency based on the tendency of tripeptide aggregation were selected in this research.The corresponding tripeptide sequences were synthesized using peptide solid phase synthesis.The tripeptide-NDI disubstituted molecule was synthesized by amide condensation using 1,4,5,8-naphthalenetetracarboxylic anhydride as a hydrophobic functional group.The self-assembly types in acid solution and basic solution were investigated by spectroscopy such as ultraviolet and circular dichroism,and the self-assembly morphology on the surface of the silicon wafer was observed by scanning electron microscopy.Those five synthesized tripeptide-NDI disubstituted molecules,[KYF]2-NDI,[FFK]2-NDI,[FYK]2-NDI,[FHF]2-NDI and[FYR]2-NDI,can self-assemble to form specific morphological structures in acid or basic solution.In acid solution the molecules self-assembly to form a spherical structure and in basic solution the molecules self-assembly to form a bamboo-leaf-like structure.More importantly,on the surface of the silicon wafer,self-assembled spherical and bamboo-leaf-like structures will further self-assemble to form a fractal structure.This hierarchical self-assembly provides an idea for the design of new nanomaterials.At the same time,the tripeptide-NDI disubstituted molecule is also a potential material for fluorescent probes.