Assembly, growth and nonlinear thermo-optical properties of nitropeptides

Self-assembly of Functional Nanostructures by Short Helical Peptide Building Blocks

The self-assembly of short peptide building blocks into well-ordered nanostructures is a key direction in bionanotechnology. The formation of β -sheet organizations by short peptides is well explored, leading to the development of a wide range of functional assemblies. Likewise, many natural proteinaceous materials, such as silk and amyloid fibrils, are based on β-sheet structures. In contrast, collagen, the most abundant protein in mammals, is based on helical arrangement. Similar to β-sheet structures, short helical peptides have been recently discovered to possess a diverse set of functionalities with the potential to fabricate artificial self-assembling materials. Here, we outline the functional roles of self-assembled nanostructures formed by short helical peptides and their potential as artificial materials. We focus on the association between self-assembled mesoscale structures and their material function and demonstrate the way by which this class of building blocks bears the potential for diverse applications, such as the future fabrication of smart devices.

Self-Healing Hydrogel from a Dipeptide and HCl Sensing

Ordered self-assembly of small organic molecules may induce novel properties in a supramolecular arrangement and can act as advance functional materials. This paper discusses the development of a new stimuli-responsive dipeptide hydrogelator containing l-phenylalanine and α-aminoisobutyric acid (Aib). The dipeptide Boc-Phe-Aib-OH, on addition with three equivalent of sodium hydroxide and water, transformed into a robust hydrogel. The transparent hydrogel is self-healing in nature. The instant gelation is highly selective toward sodium hydroxide and does not need any sonication or heating-cooling cycle. The thixotropic nature of the gel has been confirmed by rheological step-strain experiments at room temperature. Moreover, in the oil-water mixture, the compound exhibits phase-selective gelation. When the gel cylinder is cut into pieces, it does not conduct electricity, but once self-healing occurs, it conducts electricity. The diffusion of rhodamine 6G through the hydrogel indicates the dynamic nature. The hydrogel is highly sensitive toward HCl, that is, in the presence of HCl vapor, the gel becomes deformed.