Electrochemical glucose biosensor based on an osmium redox polymer and glucose oxidase grafted to carbon nanotubes: A design-of-experiments optimisation of current density and stability

• Grafting of glucose oxidase to carbon nanotubes improves enzyme activity. Design-of-experiments used evaluate optimum component amount for electrode preparation. Higher current density compared one-factor-at-a-time approach. Enzymatic electrodes based on mediated electron transfer have potential application as semi-implantable or implantable sensors. Enzyme consisting adsorbed osmium-based redox polymer crosslinked with a oxidising are promising systems continuous monitoring, but suffer from signal output magnitude and long-term stability issues. The inclusion nanosupports such multiwalled (MWCNTs) into these sensors tends increase characteristics surface coverage mediator. However, large quantities nanomaterials often necessary see significant effects. the MWCNTs dispersibility nanosupport aiding fabrication, increases Here we report design experiments (DoE) approach determine each in electrodes, using grafted nanotube support, maximise use biosensing. Using DoE while considering responses delivers set amounts where both optimised. Thus far has not been investigated response be optimised show 3.18 ± 0.30 mA cm −2 , representing 146% 50 mM phosphate-buffered saline at 37 °C containing 5 when similar other. predictive model, were then modified minimise quantity nanoconjugate showing electrochemical behaviour system, 93% less nanoconjugate. operational under was moderate only ≈ 50% amperometric retained after 12 hr use. Overcoating Nafion protective layer improved 72–75% over same period. coupling films surface, additional perm-selective membranes, and/or pulsed potentials implement intermittent sampling levels, rather than amperometry, is proposed improve stability.