Development of a tripeptide based arginine sensor via applying the concept of molecular engineering

Abstract

In this present work, we have synthesized two tripeptides and one of them is the molecular engineered version of the other one. The study shows how a single nitro group can abruptly change the physicochemical properties of a tripeptide. Tripeptide 3 shows interesting self-assembled nanoscale supramolecular architectures. We experienced a gradual transition from toroid to sphere morphology. Contrary to this, 4, the molecular engineered version of 3, organizes in a completely different manner. Instead of producing aggregated spheres, it produces a structure similar to a chain of pearls. In the case of secondary structure, compound 3 shows beta sheet-like structure while compound 4 exhibits alpha helix-like assembly. Compound 4 acts as an arginine sensor with a detection limit of 1.38 μM in the water. Furthermore, using Density-functional theory, optimization of arginine bound 4, calculation of adsorption energies, and prediction of absorption spectra were obtained which support the experimental data.