A Long-Term Stable And Flexible Glucose Sensor Coated With Poly(Ethylene Glycol)-Modified Polyurethane

Flexible biosensors have the great potential to be applied in medical diagnosis, wearable devices, fermentation and other fields. This paper proposes a manufacturing scheme of a flexible enzymatic glucose sensor coated with polyurethane modified by poly(ethylene glycol), PU-PEG, as a protective membrane, which can overcome the problems of poor consistency and short service life of the electrochemical sensor. A platinum-black electrode formed by electroplating platinum-black nanoparticles onto a flexible gold electrode is used as an enzyme carrier. The enzyme is electrosprayed evenly onto the electrode to avoid aggregation and to control quality. Glutaraldehyde is used as a cross-linking agent to immobilise the enzyme layer. Additionally, using PU-PEG as the protective membrane improves the anti-interference performance, controls the enzymatic reaction rate and makes long-term stable operation of the sensor possible. The experimental results show that the linear range of the sensor is 0.5 similar to 25 mM, the minimum detection limit is 0.25 mM, and the sensitivity is as high as 3.418 mu A/mM. The measurement results of the sensors show good consistency, with a maximum absolute deviation of only 5.52%. The effective working time in 37 degrees C bovine serum with a glucose concentration of 5 mM is up to 23 days.