A method is provided, comprising: copolymerizing a monomer comprising at least two amide groups, a monomer of formula (a) and a sulfonic acid or salt monomer, wherein R1 is CH3 or H. A polymer made by the method is provided. A method for coating an electrode is provided, comprising: providing an electrode; providing a solution of a free radical initiator, a monomer comprising at least two amide groups, a monomer of formula (a) and a sulfonic acid or salt monomer; wetting the electrode with the solution; and heating the wetted electrode; whereby the monomer comprising at least two amide groups, the monomer of formula (a), and the sulfonic acid or salt monomer are copolymerized; wherein R1 is CH3 or H. An electrode coated by the method is provided.