Development of novel glucose sensing capsules with a function of signal enhancement

为了开发一种用于体内监测间质液中葡萄糖的微创传感器系统，制备了具有信号增强功能的葡萄糖传感微胶囊，该微胶囊基于调节酶产物在胶囊膜上的转运，并研究了其响应特性。首先，提出了传感胶囊信号增强功能的理论模型，并进行了实验验证。其次，设计并合成了新型近红外染料作为植入式光学葡萄糖传感器的传感元件。最后，建立了葡萄糖传感微胶囊的制备方法。因此，采用乳液聚合法制备了以氨基为固定位点的微球。固定化酶、葡萄糖氧化酶和染料后，采用逐层法在微球表面覆盖5层聚阳离子/聚阴离子。所制备的葡萄糖传感微胶囊对葡萄糖具有快速、可逆的显色反应。

In order to develop a minimally invasive sensor system for in vivo monitoring of glucose in interstitial fluid, glucose sensing micro-capsules with a function of signal enhancement based on the regulation of transport of enzymatic products across the capsule membranes had been fabricated and their response properties were investigated. At first, a theoretical model describing signal-enhancement functions of the sensing capsule was proposed and experimentally verified. Second, novel near-infrared dyes were designed and synthesized as a sensory element of implantable optical glucose sensors. Finally, a fabrication method of glucose sensing micro-capsules was established. Accordingly, microspheres having amino moieties as immobilizing sites were prepared using an emulsion polymerization method. After immobilizing enzyme glucose oxidase and the dye, the microspheres were covered with five layers of polycation/polyanion using a layer-by-layer method. The thus prepared glucose sensing micro-capsules showed rapid and reversible color responses for glucose.