Carbonised Typha tassel-modified enzymatic electrodes for ferrocene-mediated glucose biosensor and glucose/air biofuel cell applications

This study demonstrates the application of carbonised Typha tassel (CTT) in ferrocene-mediated enzymatic glucose biosensing and enzymatic biofuel cell (EnBFC) applications. Typha tassel was carbonised under an inert atmosphere to obtain conductive CTT which was then mixed with an effective electron transfer mediator, ferrocene (Fc) obtaining a redox-active electrode material. The successful immobilisation of the glucose oxidase (GOx) enzyme was performed on a CTT-Fc modified screen-printed electrode followed by a chitosan protective coating. The resulting enzymatic electrode was electrochemically characterised as a glucose biosensor with a working range of 0–10 mM and LOD and LOQ values of 0.19 mM and 0.56 mM, respectively. The developed glucose biosensor also showed good reproducibility and reusability with RSD% values of 6.68 % and 8.75 %, respectively. Furthermore, a real sample demonstration was performed using commercial jam samples with good recovery values. Finally, an EnBFC demonstration was performed using the enzymatic biosensor as an anode and a non-enzymatic cathode prepared using platinum black on gas diffusion carbon electrodes reaching a maximum power density of 3.6 µW cm⁻². This study shows the promise of CTT as an alternative to conventional materials in enzymatic biosensor and bioelectronic applications as a suitable, cheap, and sustainable material.