A non-leaching mediator may include a polymer having a polymeric backbone, and a plurality of phenothiazine groups bonded to the polymeric backbone. The plurality of phenothiazine groups may include at least one of a phenothiazine group having the general formula (IV): and salts thereof, where n is about 9 and “R” represents the polymeric backbone to which the phenothiazine group is bonded, and a phenothiazine group having the general formula (V): and salts thereof, where n is about 9 and “R” represents the polymeric backbone to which the phenothiazine group is bonded.