Thermal and aqueous stability improvement of graphene oxide enhanced diphenylalanine nanocomposites

Kate Ryan,Sabine M Neumayer,Harsha Vardhan R Maraka,Nicolae-Viorel Buchete,Andrei L Kholkin,James H Rice,Brian J Rodriguez

doi:10.1080/14686996.2016.1277504

Abstract

Nanocomposites of diphenylalanine (FF) and carbon based materials provide an opportunity to overcome drawbacks associated with using FF micro- and nanostructures in nanobiotechnology applications, in particular their poor structural stability in liquid solutions. In this study, FF/graphene oxide (GO) composites were found to self-assemble into layered micro- and nanostructures, which exhibited improved thermal and aqueous stability. Dependent on the FF/GO ratio, the solubility of these structures was reduced to 35.65% after 30 min as compared to 92.4% for pure FF samples. Such functional nanocomposites may extend the use of FF structures to e.g. biosensing, electrochemical, electromechanical or electronic applications.

Highlights

The combination of materials into nanocomposites provides unique design possibilities, potentially leading to, for example, high performance biomimetic materials comprising biopolymers and nanomaterials at the nanometer scale [1, 2]
Addition of graphene oxide (GO) to the sample solution appears to impact the morphology of structures; self-assembly into tubes persists
Increasing the GO content to a ratio of 2:1 further inhibits dissolvability (Figure 3(d)) with only 33.3 ± 10.9% of the sample dissolved after 5 min. This percentage stays approximately constant and is 35.6 ± 10.4% after 30 min. These findings suggest that the poor aqueous stability of FF tubes that is limiting especially for biomedical applications, may be overcome to a significant extent upon addition of GO

Summary

Introduction

The combination of materials into nanocomposites provides unique design possibilities, potentially leading to, for example, high performance biomimetic materials comprising biopolymers and nanomaterials at the nanometer scale [1, 2]. Whereas carbon based nanomaterials such as carbon nanotubes (CNTs) can modify mechanical, thermal, and electrical properties [3,4,5] of a nanocomposite [6, 7], the biocompatibility and biodegradability of biopolymers can unlock biomedical applications for e.g. tissue engineering [8]. Due to their ability to hierarchically self-assemble from functional molecular units into micro- and nanostructures, peptides are ideal candidates for nanoarchitectonics-based material design [9, 10]. The instability of FF nanotubes in solution is a major limitation to realizing FF nanotube-based biosensors or drug delivery systems

Methods

Results

Conclusion