A new paper (open access) shows that high quality carbon sources are in fact not needed. Look at the labels of the Raman spectra and try not to laugh too hard - this is serious science.Need a few specifics on the materials (I do - "Plastic"?! Seriously, they labeled it just "Plastic"?)
"Six different carbon sources were used: Girl Scout Cookie (the Girl Scouts of America Troop 25080 from Houston, Texas, provided the cookies, shortbread flavor), chocolate (Chocolate Kennedy Half Dollar Gold Coins), grass (Ophiopogon picked at Rice University), plastic (Fisherbrand polystyrene Petri dishes, catalog # 08-757-12), dog feces (Miniature Dachsund) and a cockroach leg (American cockroach caught in a house). The grass and the dog feces were dehydrated in a vacuum oven (102 Torr) at 65 °C for 10 h before being used in the growth process."Where they got the nerve to try some of those options, I can't imagine. Technology Review has estimates that a single box of the cookies can product $15 billion dollars worth of graphene, so maybe order a few extra boxes next year when the Girls Scouts are at your door.
Hat tip to Neil Withers (twitter - @neilwithers) for the lead