An enzymatic glucose/O2 biofuel cell operating in human blood.

Enzymatic biofuel cells (BFCs) may power implanted medical devices and will rely on the use of glucose and O2 available in human bodily fluids. Other than well-established experiments in aqueous buffer, little work has been performed in whole human blood because it contains numerous inhibiting molecules. Here, we tested our BFCs in 30 anonymized, random and disease-free whole human blood samples. We show that by designing our anodic and cathodic bioelectrocatalysts with osmium based redox polymers and home-made enzymes we could reach a high selectivity and biofunctionnality. After optimization, BFCs generate power densities directly proportional to the glycaemia of human blood and reached a maximum power density of 129µWcm(-2) at 0.38V vs. Ag/AgCl at 8.22mM glucose. This is to our knowledge the highest power density attained so far in human blood and open the way for the powering of integrated medical feedback loops.