The Animus could control beings that were in contact with gold, which led to it controlling the Zarbi. (TV: The Web Planet) The Keratin could similarly use gold to conduct and amplify their psychic powers. (AUDIO: The Glittering Storm)
In payment for his service, the Master offered Chang Lee two bags of gold dust that was kept within the Doctor's TARDIS. The Master claimed the dust, along with the TARDIS, had been once his before the Doctor stole it. After the Eighth Doctor defeated the Master, he let Lee take the gold dust. (TV: Doctor Who)
Owing to its non-corrosive nature, gold essentially choked the Cybermen's respiratory systems. The glittergun, a weapon used during the Cyber-Wars, fired gold dust at its targets to exploit this weakness. Adric's badge was gold-edged, allowing for the doctor to grind it into the cyber leader's chest and asphyxiate him. (TV: Earthshock) Gold appeared to affect some varieties of Cybermen in the way that silver affected werewolves, so that gold coins or gold-tipped arrows fired at them had the same effect. (TV: Silver Nemesis).
During a time period in which the Cybermen had been reduced to small remnant groups wandering around the galaxy, one group tried to take revenge by making a desperate attempt to blow up the remnants of the planet Voga, a planetoid of pure gold that had wandered into the Sol system and become a moon of Jupiter. They hoped that this would disrupt their enemy's supply of the element. (TV: Revenge of the Cybermen)