One-pot bottom-up synthesis of a 2D graphene derivative: application in biomolecular recognition and nanozyme activity

Advances in Biologically Applicable Graphene-Based 2D Nanomaterials

Climate change and increasing contamination of the environment, due to anthropogenic activities, are accompanied with a growing negative impact on human life. Nowadays, humanity is threatened by the increasing incidence of difficult-to-treat cancer and various infectious diseases caused by resistant pathogens, but, on the other hand, ensuring sufficient safe food for balanced human nutrition is threatened by a growing infestation of agriculturally important plants, by various pathogens or by the deteriorating condition of agricultural land. One way to deal with all these undesirable facts is to try to develop technologies and sophisticated materials that could help overcome these negative effects/gloomy prospects. One possibility is to try to use nanotechnology and, within this broad field, to focus also on the study of two-dimensional carbon-based nanomaterials, which have excellent prospects to be used in various economic sectors. In this brief up-to-date overview, attention is paid to recent applications of graphene-based nanomaterials, i.e., graphene, graphene quantum dots, graphene oxide, graphene oxide quantum dots, and reduced graphene oxide. These materials and their various modifications and combinations with other compounds are discussed, regarding their biomedical and agro-ecological applications, i.e., as materials investigated for their antineoplastic and anti-invasive effects, for their effects against various plant pathogens, and as carriers of bioactive agents (drugs, pesticides, fertilizers) as well as materials suitable to be used in theranostics. The negative effects of graphene-based nanomaterials on living organisms, including their mode of action, are analyzed as well.

Graphene oxide as a dual template for induced helicity of peptides

Artificial template-mediated fabrication of secondary structures within peptides always attracts great interest in biological systems due to several biomimetic interactions. In all earlier studies, a uniform template containing molecules/nanomaterials was used to target only one type of peptide at a time, which extensively limits the diversity in the generation of artificial protein surface/binding sites. This limitation can be overcome by the incorporation of more than one binding template (heterogeneity) in a single system, for example, Janus nanomaterials, which are challenging and difficult to synthesize. In this context, graphene oxide (GO) is considered an artificial binding site (template). It contains two distinctive binding zones, i.e., surface and edge, which can induce the secondary structure of peptides based on complementary interactions. To establish our concept, we have implemented a hybrid sequence i.e., i, i + 4, i + 7 and i + 11 pattern peptides, which defines a more linear surface, suitable for recognition by the two-dimensional GO. Depending on the amino acid residue at the specific locations, we observed substantial enhancement of peptide helicity either at the surface or at the edges of GO from the random coil. However, non-interacting peptides remain as a random coil. We have established this by circular dichroism study at various conditions, as well as atomic force microscopy and optical imaging study. Furthermore, we have also established our observations using molecular dynamics (MD) simulations. This study reveals that the synthesized GO-peptides composite with different secondary structures and recognition residues can mimic biological systems.