Polysulfonium as a new electrode-modifying polyelectrolyte

A new type of cationic polyelectrolyte, poly(methylsulfonio-1,4-phenyleneth io-1,4-phenylene trifluoromethanesulfonate)? that adheres to a glassy carbo n electrode surface has been employed to bind a ferricyanide anion to the e lectrode surface from electrolyte solutions. The complex incorporated by th e polyelectrolyte shows significant shifts in formal potential to less posi tive values due to the stronger binding of ferricyanide by the polycation c oating than that of ferrocyanide. The apparent formal potential for the inc orporated ferricyanide/ferrocyanide redox couple changes as the concentrati on of supporting electrolyte is varied. The polycation coating is anion-per mselective when a methanesulfonate is used as a supporting electrolyte. (C) 2001 Elsevier Science B.V. All rights reserved.