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

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), beta-lactoglobulin, ovalbumin, lysozyme, and hemoglobin are used to exfoliate graphite and the exfoliation efficiency 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 efficiencies exceeding 4 mg mL(-1) h(-1). Raman spectroscopy and transmission electron microscopy indicated 3-5 layer, defect-free graphene of 0.5 mu m size. Graphene dispersions loaded on a cellulose paper (650 mu g cm(-2)) showed the film conductivity of 32 000 S m(-1), which is much higher than graphene/polymer composites. Our method yielded approximate to 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 degrees C), and in fetal bovine serum, for more than two months. These findings may lead to the large scale production of graphene for biological applications.