What benefit does using TLG's micrographite have in producing the graphene oxide? Sure there are studies that have shown (http://iopscience.iop.org/article/10.1088/2053-1583/3/1/014006) what the starting material is can effect the graphene produced but none of these were the 'micro-graphite' that TLG produces, so I don't think anyone could say with any certainty that TLG's material made any difference - they probably could have used flake graphite concentrate and had the exact same result.
There is quite a lot of processing that goes on in producing that concentrate, it's not a one step conversion that they reported in phase 1. The title of the article is thus misleading as it ignores the processing that went on to produce the concentrate.
They could have used an improved Hummers method without NaNO3 and avoided a good deal of the toxic fumes it produces. Indeed I'd be surprised if this method will be used to produce reduced Ag-GO commercially, it's not exactly amenable to scaling, indeed there are improved methods for producing graphene-oxide that are scalable, and they all often involve exfoliation - electro or sonic, eg -http://pubs.acs.org/doi/abs/10.1021/nn1006368 or http://www.sciencedirect.com/science/article/pii/S0008622313006891 and others.
Why they are using the concentrate in this manner at all is a little perplexing. As you have stated until you test it you don't really know if using graphene will provide a worthwhile benefit over using micrographite, but if your going to use a by-product of graphene production in a clumsy synthesis to produce umm graphene I just think something there is not quite right.
Have to agree with daveg here, it's not the starting material that made any difference to the efficacy of the sensor, it was using graphene rather than other materials that provided the benefit.
