Pencil-Lead-Based Quasi-Equilibrium Glucose Biosensors

Foreign body response is the main reason for the limited lifetime of implantable glucose biosensors. A new measurement strategy exerting minimal disturbance from the equilibrium glucose concentration in the sensor compartment has been proposed to mitigate its adverse effects on the sensor signal. Here, a new measurement strategy using automatically fabricated and robust pencil-lead-based glucose biosensors is implemented. The sensor response depends on critical parameters such as redox-polymer film thickness, film uniformity, rigidity, polymer composition, and the ratio between the enzyme and the polymer. These parameters are controlled by introducing a short-chain redox polymer, a low crosslinker amount, a short-chain electrografting agent and linker, pulse electrografting, and an automated fabrication procedure.