negative potential on floated metal skimmer

Hello all, I wanted to know if there will be an undesirable build up of charge if I place a negative potential on a floated metal skimmer (tapered cylinder). I am trying to attract positively charge molecules to the negatively charged skimmer, where the skimmer if isolated from all electrical connections (and ground), except for one lead which is connected to a BNC cable that goes to the power supply. If I keep the voltage low (