具高分子保護膜之植入式微型化酵素感測器研製

Abstract

本研究利用微機電技術製作三極式電化學微感測電極監測生理參數Glucose、Lactate，並針對微小化參考電極需具穩定性、可再現性、可靠性之需求，以及考量植入式感測器可能面臨之問題，提出藉由覆蓋於感測器上之保護膜(Protective membrane)來改善，期望除了能提高感測器之生物相容性或耐久性外，進而可同時提高微小化參考電極的穩定性。此外，為了將檢測系統即電化學感測系統之架構簡化與微小化，本研究也設計出單電源(+3V)定電壓之電化學感測電路，達到最終微小化之目的。 觀察不同保護膜材料對參考電極之穩定性探討，由結果顯示Polyurethane(PU)保護膜確實能改善參考電極之穩定性，因此後續實驗以Polyurethane(PU)保護膜為主，觀察其對酵素電極之感測影響，結果發現具Polyurethane(PU)保護膜之Glucose biosensor或Lactate biosensor並不會影響其感測能力，且動物實驗中得知植入數天後具Polyurethane(PU)保護膜之Glucose biosensor或Lactate biosensor同樣不會影響其感測能力！而觀察植入後之感測器電極表面，發現所有感測器植入數天後電極表面之Polyurethane(PU)保護膜結構皆無破壞，仍具保護功能！

In our study, preparation of the three-electrode biosensors used the MEMS technology. The three-electrode biosensors measured glucose and lactate using glucose oxidase (GOD) and lactate dehydrogenase (LDH). Biomedical and implantable sensor applications require stable, reproducible, reversible, and reliable miniaturized reference electrode , made of biocompatible materials. So the present study reports the application of protective membrane on the device, which exists both biocompatibility and permselectivity, and acts as a surface coating material for the outer layer of the Bio-sensor. For miniaturization of sensing system, we design a single-supply circuit. Thus, our study used difference protective membrane to assure the long-term stability of the Ag/AgCl reference electrode. From those results, we can know that reference electrode with polyurethane protective membrane is more stable than the one without protective membrane. In vivo performance, the sensor with polyurethane protective membrane can also work when implanted subcutaneously in a rat.