Graphene oxide forms crystals with a 2.1 nm structure, there's a band there to detect but it's at a very high frequency above visible light. A simple resistance test is more doable, if someone is more conductive they have something in them, it's just non-specific as to what is conductive. It's not really safe to aim an x-ray spectroscopy gun at someone, so you'd need samples anyway.
Graphene oxide forms crystals with a 2.1 nm structure, there's a band there to detect but it's at a very high frequency above visible light. A simple resistance test is more doable, if someone is more conductive they have something in them, it's just non-specific as to what is conductive. It's not really safe to aim an x-ray spectroscopy gun at someone, so you'd need samples anyway.