Casein mediated green synthesis and decoration of reduced graphene oxide

•A green eco-friendly method for casein mediated reduced graphene oxide synthesis.•Decoration of casein molecules on the surface of graphene sheets stabilizes it.•Amino groups of aspartic, glutamic acid residues in casein cause reduction of GO.

This research is mainly focusing on one-step biosynthesis of graphene from graphene oxide and its stabilization using naturally occurring milk protein, casein. The synthesis of casein reduced graphene oxide (CRGO) was completed within 7 h under reflux at 90 °C with the formation of few layered fine graphene nanosheets. UV–Vis, XRD, XPS analysis data revealed the reduction process of the graphene oxide. Results of FT-IR, HPLC and TEM analysis have shown that the ensuing material consists of graphene decorated with casein molecules. Aspartic acid and glutamic acid residue present in casein molecules are responsible for the reduction of graphene oxide.

Graphical abstractIncorporated casein molecules via amino linkage onto the surface of graphene cause the stability of the graphene via their surface carboxylic acid groups [25] and [26]. Aspartic acid and glutamic acid residue of casein molecule are responsible for the graphene oxide reduction.Figure optionsDownload full-size imageDownload as PowerPoint slide