题目：Micro/Nano- Approaches for Continuous Glucose Monitoring
主讲内容：This talk is focused on implantable glucose biosensor, including Pt coil-type implantable sensor, carbon nanotube (CNT) fiber based enzymatic sensor and CNT/Ni nanocomposite based non-enzymatic sensor. To improve the life-time of glucose sensor implanted underneath the skin, a new type of Pt coil electrode was introduced, which is able to immobilize much more GOD than traditional needle type electrode. The selection of semi-permeable membrane is critical for the sensor linearity. The sensors could be survived for 4 weeks during in-vivo test, and histology revealed that the fibrous capsules surrounding hydrogel-coated sensors were thinner than before. A novel brush-like electrode based on carbon nanotube (CNT) fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor was demonstrated. The electrode end-tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical ‘flex’. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for Pt-Ir coil electrode. In addition, gold coating of the CNT fiber electrode resulted in extending the glucose detection limit to 25 µM. A highly sensitive nonenzymatic amperometric glucose sensor was fabricated by using Ni nanoparticles homogeneous dispersed within and on the top of a vertically aligned CNT forest. The CNT/Ni nanocomposite sensor exhibited a great enhancement of anodic peak current after adding 5mM glucose in alkaline solution. The sensor can also be applied to the quantification of glucose content with a linear range covering from 5 µM to 7 mM, a high sensitivity of 1433 µA mM-1 cm-2, and a low detection limit of 2 µM.