pirahna solution

Hi,
I'm a biologist.
I'm doing experiments with biomolecules to see if they bind to gold.
I've seen that to have a clean gold surface, it is necessary to treat
the gold with piranha solution and I now it is a very dangerous
solution.
Anibody can suggest me how to do, handle, use and throw away this
solution (using biological equipments)?
And if exists a simpler way to obtain clean gold surface?
Thank you in advance,
Andrea

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