Rapid sub-micromolar amperometric enzyme biosensing with free substrate access but without nanomaterial signalling support: oxidase-based glucose detection as a proof-of-principle example.

High-sensitivity electrochemical glucose biosensing has so far been possible only through incorporation of nanomaterials into the glucose oxidase-(GOx) containing polymer layer on the detector surface. Here, as a conceptionally novel simplified option, pure gelatin thin films with covalently attached GOx were used to convert platinum (Pt) disk electrodes into rapidly responding amperometric glucose probes with a sub-micromolar limit of detection. The advanced enzymatic tools are easy to make and, as is crucial for a focus on waste minimization, green and sustainable, through restriction of sensor modification to readily available economical materials.