Following the successful screening on glassy carbon electrodes for both lactate and creatinine, we integrated the sensing enzymes and corresponding oxygen scavenging system, into the screen-printed electrode systems, replicating the approach used for the glucose biosensors. This enabled the fabrication of single-use, self-filling lactate and creatinine biosensors. The effects of the O2-scavenging systems were tested across a broad range of analyte concentrations using chronocoulometry (Figure ). In absence of the O2-scavenger, charges measured at 0.4 V vs pseudo RE after 10 min for the low millimolar concentrations range were about 50% lower compared to those measured under inert atmosphere for both sensors. Higher concentrations (> 5 mM for lactate, > 10 mM for creatinine), showed less charge loss, which is consistent with the results observed for glucose sensing.