Good one.
Gold is a hedge.
You hold it close to yourself, when you think you
have to haul it around in a portable way.
The reason that does not work, is if you run into
any criminals, that gold will be taken off your person,
quick as a wink.
There was a robbery at an airport here, and a significant
quality of it was stolen.
It's heavy dense stuff, which means you cannot run very fast
holding a whole bar of it. Filling up the trunk of your car
with it, would likely break the suspension.
It would be hard to make a nanobot out of it, because there
aren't a lot of things you can react it with. Does it chelate ?
Does it bind ethylene diamine tetra-acetic acid (EDTA) ?
(Only in an indirect way, by attacking the things polluting the gold)
https://www.sciencedirect.com/science/article/abs/pii/S0304386X19311260
So if we can't find a tricky way of "grabbing it", with the claws of
EDTA, then it is going to be pretty hard to make a nanobot. You can
definitely make very thin foils with gold, but we need some thermal
property, an expansion effect, a memory metal, at least *something*
interesting as a property, to make toys with it.
It does a good job of protecting less-noble metals (in a plating stackup).
Paul