Microfabricated devices for flexible sensing at the biointerface

生物兼容和可生物降解的、机械灵活的、符合人体软组织和器官的传感器是非常可取的，因为它们提供了一种测量和监测活动的手段。在这项研究中，将设计和制造可生物降解的丝绸，以测试指示病理的生物标记物的测量可行性。该项目将研究各种电化学生物传感器设计(一维线、二维片和三维块)，使用可生物降解的丝绸和柔性和整合形式的导电聚合物来测量乙酰胆碱、C反应蛋白、血管内皮生长因子(VEGF)等模型生物标志物。提出的创新是通过丝素蛋白光刻技术制备包括导电聚合物聚(3，4-乙二氧基噻吩基)：聚苯磺酸盐(PEDOT：PSS)和丝蛋白(丝素和丝胶)的功能性生物传感器的方法。生物传感器的结构-性能关系将通过以下具体目标进行研究。(1)研究提高电化学响应和机械性能的组成关系，并使其能够选择性地进行检测；(2)研究多尺度和多维度(一维导线、2D薄片和3D支架网络)的传感器制造策略，使其能够与软组织相一致。适当的识别元件(抗体和适配子)将固定在电极表面以对抗目标分析物。传感器的响应和机械性能将被设计为与目标软组织的顺应性附着，同时将细胞毒性降至最低。可行性传感器实验将在体外利用生理条件下的细胞种子进行。将对传感器响应的重复性进行表征，并对传感器设计进行修改，以适应所需的灵敏度、选择性和重复性。建议开展教育和外联活动。将制作微型和纳米级物体的触觉和3D打印模型，让学生对各种传感器架构有直接的可视化和质感。在国际和平协会组织的年度外展活动中分享这些信息，将有助于激励年轻学生投身工程和科学事业。

Sensors that are biocompatible and biodegradable and are mechanically flexible and conform to soft tissues and organs in the human body are highly desirable as they provide a means to measure and monitor activity. In this research, biodegradable silk will be engineered and fabricated for testing of measurement feasibility of biomarkers that are indicative of pathology. The project will investigate various electrochemical biosensor designs (1D wires, 2D sheets and 3D blocks) using biodegradable silk and conducting polymers in flexible and conformable formats for measuring such model biomarkers as acetylcholine, C-reactive protein, vascular endothelial growth factor (VEGF). The innovation proposed is the method of fabricating functional biosensors comprising the conducting polymer poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and silk proteins (fibroin and sericin) via techniques developed by silk protein lithography. The structure-property relationships of fabricated biosensors will be investigated through the following specific aims. (1) Investigate the compositional relationships that enhance electrochemical response and mechanical properties, and enable their selective detection, and (2) Investigate sensor fabrication strategies for sensors in multi-scales and dimensions (1-D wires, 2D sheets, and 3D scaffold network) so that they can conform to soft tissue. Appropriate recognition elements (antibody and aptamers) will be immobilized on electrode surface against the target analyte. Sensor response and mechanical properties will be engineered for conformable attachment to the target soft tissue while minimizing cytotoxicity. Feasibility sensor experiments will be conducted in vitro using stock seeds of cells under physiological conditions. Reproducibility of sensor response will be characterized and sensor design will be modified to accommodate required sensitivity, selectivity, and reproducibility. Education and outreach activities are proposed. Haptic and 3D printed models of micro and nanoscale objects will be fabricated to give students a direct visualization and textural feel for the various kinds of sensor architectures. Sharing of these in annual outreach activities organized by the PI will help inspire young students into engineering and science careers.