【作者】 张曦；

【导师】 张拥军；

【作者基本信息】 南开大学 ， 高分子化学与物理， 2012， 博士

【摘要】 在本论文中，我们利用苯硼酸基团能够和顺式邻二醇结构形成可逆的苯硼酸酯共价键的性质，用丙烯酰胺和3-丙烯酰胺基苯硼酸的共聚物(P(AAm-AAPBA))和聚乙烯醇(PVA)进行层层自组装，制备了超薄PVA/P(AAm-AAPBA)层层自组装水凝胶膜。该薄膜可以在反射光谱上显示Fabry-Perot条纹，在葡萄糖的作用下，薄膜的溶胀程度增大，Fabry-Perot条纹发生移动，可以直观地反映出葡萄糖浓度的变化。这一性质使得该水凝胶膜适于用作葡萄糖传感器。因为PVA/P(AAm-AAPBA)层层自组装膜的厚度处于次微米或微米级，比普通的水凝胶膜传感器薄两个数量级，所以它的响应速率很快，特征响应时间可达十几秒，这是目前已知的水凝胶膜类传感器的最快响应速率。这一快速响应的葡萄糖传感器在对糖尿病人的血糖水平进行实时持续监控方面具有潜在的应用价值。为了提高层层自组装水凝胶膜传感器在生理pH值下的葡萄糖响应性，我们又向聚合物中引入了二甲胺基丙基丙烯酰胺(DMAPAA)和丙烯酸(AAc)，利用硼-氮作用降低苯硼酸的pKa，利用丙烯酸和PVA的羟基进行交联，制备出在生理pH下具有较好葡萄糖响应性和稳定性的传感器。此外，层层自组装膜非常适合用作药物释放载体。我们以胰岛素和聚乙烯醇形成的缀合物(insulin-PVA)与P(AAm-AAPBA)制备了以可逆苯硼酸酯键连接的insulin-PVA/P(AAm-AAPBA)层层自组装膜，采用低苯硼酸含量的P(AAm-AAPBA)以降低膜的稳定性，将其用于自调节的胰岛素释放。当层层自组装膜浸入水溶液中，随着苯硼酸酯共价键断裂，层层自组装膜逐渐解离，胰岛素就会释放到介质中，释放速率可以通过pH值、离子强度和葡萄糖浓度进行调节。更多还原

【Abstract】 Most hydrogel-based biosensors have been hindered in their practicalapplications due to the slow response. In this dissertation we designed hydrogelsensors with quick response from ultrathin hydrogel films, by using layer-by-layer(LBL) assembly technique, which is a simple but versatile approach for filmfabrication. Specifically, with formation of reversible covalent phenylboronate esterbond as the driving force, glucose-responsive hydrogel films can be facilelyfabricated by layer-by-layer assembly, and their thickness is controlled on submicronor micron scale, which is2orders of magnitude thinner than films used in ordinaryhydrogel sensors. In the presence of glucose, these films swell to a larger degree,which infers good glucose-responsive performance. Furthermore, the response islinear and reversible. Glucose-induced swelling can be reported via the shift ofFabry-Perot fringes. Most importantly, the response is quite fast, making it possible tobe used for continuous glucose monitoring.In the later work, in order to enhance the sensors’ performance,N,N-Dimethylaminopropyl acrylamide (DMAPAA) and acrylic acid (AAc) areintroduced into LBL films. Under this experiment setup, the pKa of phenylboronicacid is reduced by B-N interaction. Besides, the cross-link of PVA and acrylic acidincreases the stability of the films. Therefore, in this way, stable glucose-sensorscapable of using under phycological pH are prepared.Under proper conditions, layer-by-layer films may disintegrate as a result of thebreakage of the bonds, which makes them suitable for controlled drug release.Therefore, the films fabricated using reversible phenylboronate ester bonds as drivingforces also disintegrate gradually in aqueous solutions. In this work, insulin canrelease from LbL films fabricated from insulin-PVA (PVA: polyvinyl alcohol)conjugate and poly[acrylamide-co-3-(acrylamido)-phenylboronic acid]. Whenimmersed in an aqueous solution, the films disintegrate gradually, thus insulin isreleased into the media. Specifically, the release rate can be tuned by pH, ionicstrength and glucose concentration, making this system potential for self-regulated insulin release.更多还原