To evaluate the performance of 2%Fc12-PF6/MO/GOx, a comparison was made with the previously reported Fc12-Br bioelectrode system 21 (see Figure ). Surprisingly, despite the 2%Fc12-PF6/MO/GOx system had employed higher %wt redox probe, both sensitivity and KM did not display significant differences between the two types of the systems. The fact that these enzymatic kinetics results looked comparable suggests that the concentration of redox probe may not be the limiting factor affecting the magnitudes of the amperometric response. Instead, it is possible that the concentration of the enzyme entrapped within the medium plays a more crucial role.