The effect of the O2-scavenger on glucose sensing in the self-filling sensor strips was assessed by means of chronocoulometry (Figure ) over a wide glucose concentration range pertinent to blood glucose levels. Similarly to the current response at the GCE, the charges measured in ambient air without O2-scavenger were lower than those measured under inert atmosphere, particularly at glucose concentrations below 20 mM (Figure ). The effect was less pronounced at higher concentration due to the limited availability of O2 in the small volume capillary and the hindered replenishment of O2 from ambient air through the capillary channel.