Lets try to break this down so we can understand it better
is it possible to chemically bond
In many cases, yes,
bond iron to gold
oops, not in this case. Usually, two metals from a mixture called an alloy. Something like gold or silver telluride exists, but tellurium is a metaloid. Something like iron is too metallic.
by a ch elating agent such as citric acid in an aquaous solution ?
Well, a chelating agent could form a compound with two metals, like sodium calcium EDTA. But I'd never heard of gold and iron behaving this way. I think its unlikely, but I doubt the every possible organic molecule has been tried as a chelating agent.
Where are you going with this question?