Kitchen Chemistry 101: Multigram Production of High Quality Biographene in a Blender with Edible Proteins

Abstract

A facile method for producing unoxidized, pristine graphene under biologically benign conditions is essential for widespread biomedical applications of graphene. Rate of exfoliation, scalability, high quality, controlled functionalization, size and large fl ake size are highly desired. Rapid production of biofunctionalized, micrometer size, and defect free, few layer graphene (FLG) is reported here. Further, we have systematically examined Kitchen Chemistry 101: Multigram Production of High Quality Biographene in a Blender with Edible ProteinsAjith Pattammattel and Challa Vijaya Kumar * A high yielding aqueous phase exfoliation of graphite to high quality graphene using edible proteins and kitchen chemistry is reported here. Bovine serum albumin (BSA), β-lactoglobulin, ovalbumin, lysozyme, and hemoglobin are used to exfoliate graphite and the exfoliation effi ciency depended on the sign and magnitude of the protein charge. BSA showed maximum exfoliation rate, facilitated graphite exfoliation in water, at room temperature, by turbulence/ shear force generated in a kitchen blender at exfoliation effi ciencies exceeding 4 mg mL −1 h −1. Raman spectroscopy and transmission electron microscopy indicated 3-5 layer, defect-free graphene of 0.5 µm size. Graphene dispersions loaded on a cellulose paper (650 µg cm −2 ) showed the fi lm conductivity of 32 000 S m −1 , which is much higher than graphene/polymer composites. Our method yielded ≈7 mg mL −1 , BSA-coated graphene with controllable surface charge, which is stable under wide ranges of pH (3.0-11) and temperature (5.0-50 °C), and in fetal bovine serum, for more than two months.These fi ndings may lead to the large scale production of graphene for biological applications.

Controlling the Graphene–Bio Interface: Dispersions in Animal Sera for Enhanced Stability and Reduced Toxicity

“…The efficiencies are compared with our previous study which used bovine serum albumin (BSA, 3.0 mg/mL, 4.0 mg mL -1 h -1 ) 8 and 10% serum contains similar levels of total protein in serum. Thus, the comparable levels of graphene efficiencies suggest that serum proteins may be the primary active species responsible for the observed exfoliation efficiencies in these sera.…”

“…Direct exfoliation of graphite to graphene in water is achieved by using small organic molecules, 12 amphiphilic stabilizers such as surfactants, 13 proteins, 8,14,15 and carbohydrates. 16 The reagent used for this process (exfoliating agent) should stabilize graphene in water, but it should not be toxic to most biological systems, if the preparations are to be used for biological applications.…”

Production and stability of mechanochemically exfoliated graphene in water and culture media

“…Some studies have pursued this by exfoliation of graphite in aqueous media with, for example, pyrene derivatives, [10][11][12] anionic surfactants, 13,14 polymers, 15,16 or proteins. [15][16][17][18] Therefore, whereas GO powders can be directly dispersed in the cell culture medium (CCM) or transferred through dilution from water, 8 pristine (chemically non-modified) GR in aqueous suspension is mostly handled with its accompanying dispersant, 15,17 or (hardly ever reported) GR powders directly dispersed in CCM. 19 However, these latter authors found adsorptive artifacts due to GR large surface area, which cause non-covalent interactions with the CCM components.…”

Facile and size-controllable preparation of graphene oxide nanosheets using high shear method and ultrasonic method

“…Recently, shear mixer was introduced to exfoliate the graphite into individual graphene nanosheets [3,4,[38][39][40]. Because the oxygen-containing groups binding on carbon atoms will increase the interlayer spacing of graphite oxide, and make the layered graphite oxide easier to cleave [10,41].…”