Enzymeless glucose sensor integrated with chronically implantable nerve cuff electrode for in-situ inflammation monitoring

Using glucose concentration as an inflammation responsive element, we newly established an enzymeless glucose sensor integrated with a chronically implantable peripheral nerve cuff electrode for continuous and in-situ monitoring of local inflammation. The glucose sensor integrated with a nerve cuff electrode was fabricated on a polyimide substrate side-by-side, then the glucose sensor and nerve cuff electrode were reversely folded, and were located inside and outside, respectively. The experimental results reveal that the electroplated black Pt working electrode of the glucose sensor shows an enhancive surface roughness factor of 16.41 and had a good distribution on the flexible polyimide surface, which exhibits distinctly enhanced electro-catalytic activity compared to that obtained with plain Pt. Amperometry and electrochemical impedance spectroscopy indicated that the fabricated sensor had a sensitivity of 7.17 μA/mM cm2, an outstanding detection limit of 10 μM, significant selectivity, and excellent recovery performance for enzymeless glucose detection. In order to evaluate the feasibility for inflammation monitoring in the immediate vicinity of the implantable peripheral nerve cuff electrode, the association of an evoked nerve signal recording and glucose concentration was investigated through ex-vivo test using the sciatic nerve of a SD rat.