We recently described a redox polymer with an Os(N, N'-dialkylated biimidazole)(3)(2+/3+) redox center with a redox potential of - 195 mV vs. Ag/AgCl, 800 mV reducing relative to its 2,2'-bipyridine analog. The tethering of the centers to a poly(4-vinylpyridine) backbone through a 13 atom long spacer arm, provided for an apparent electron diffusion coefficient as large as 5 x 8.10(-6) cm(2) s(-1). The glucose electro-oxidation catalyst formed by "wiring" glucose oxidase with this polymer allowed the electro-oxidation of glucose already at -360 mV vs. Ag/AgCl at pH 7.2, near the reversible potential of glucose oxidase, at a current density of 1.3 mA cm(-2) in the presence of 32 mM glucose concentration. Here we consider the parameters affecting the characteristics of this anode, compare the characteristics with those of an anode made with a short-tethered "wire" and describe the optimization of the composition of the "wired" glucose oxidase. (C) 2004 Elsevier B.V. All rights reserved.