Material Synthesis for applications in Bioelectronic Devices

生物电子学领域目前正因新应用的出现而得到加强，这是由于有机半导体材料性能的迅速进步而得以实现的，这些材料在包括传感器和电化学晶体管在内的一系列设备中充当有源层。有机材料可以定制为具有生物相容性的界面，并具有类似的力学性能，如杨氏模量、相容性和延展性。有机材料的易于集成拓宽了应用范围以及设备的使用寿命。分子设计和合成可以促进半导体聚合物结构中的分子功能，旨在表现出特定的物理性能，如抗拉强度、水合作用和渗透性，以及电学性能，如导电性和电容。有机生物电子学中使用的一个示例性装置是有机电化学晶体管（OECT），它能够放大和转导生物信号，因此充当阳离子和代谢物的传感器。我们建议通过设计和合成一系列具有以下标准的半导体聚合物来改善基于PEDOT的器件的当前性能。它们本质上是半导体的，但可以在水的电化学窗口内的电压下掺杂，确保晶体管电极的空穴注入，而不是水氧化。这需要富电子共轭芳香族聚合物骨架，电离电位小于约5.0 eV。噻吩和噻吩共聚物一般满足这一要求。此外，聚合物应具有较高的载流子迁移率。这需要相对共面的聚合物骨架具有紧密的分子间相互作用和有序性。这些技术的关键是组织和电子之间的高质量接口。有机电子材料与生物分子具有相似的化学“性质”，可以设计成各种形式，包括具有类似于软组织的杨氏模量并具有离子导电性的水凝胶。此外，有机物的结构可以通过合成化学来调节，它们的生物学特性可以通过各种功能化策略来控制。最后，有机电子材料可以与各种机械支架集成，从而产生具有形状因素（符合要求、可拉伸、纤维性、3D多孔性）的设备，从而能够与生物系统集成。

The field of bioelectronics is currently being augmented by the emergence of new applications, enabled by rapid progress in the performance of organic semiconducting materials which serve as the active layer in a range of devices including sensors and electrochemical transistors. Organic materials can be tailored to exhibit biocompatible interfaces and possess similar mechanical properties such as Youngs modulus, conformability and ductility. The facile integration of organic materials broadens the scope of applications as well as the lifetime of devices. Molecular design and synthesis can facilitate molecular functionality within the semiconducting polymer structure, designed to exhibit specific physical properties such as tensile strength, hydration and permeability, combined with electrical properties such as conductivity and capacitance. One exemplary device employed in organic bioelectronics has been the organic electrochemical transistor (OECT), which is able to amplify and transduce biological signals and therefore act as a sensor to both cations and metabolites. We propose to improve the current performance of PEDOT based devices by the design and synthesis of a series of semiconducting polymers with the following criteria. They will be be intrinsically semiconducting, but can be doped at voltages within the electrochemical window for water, ensuring hole injection from the transistor electrode, and not water oxidation. This requires an electron rich conjugated aromatic polymer backbone, with an ionization potential less than approximately 5.0 eV. Thiophene, and thienothiophene copolymers generally meet this requirement. Additionally, the polymers should have a high charge carrier mobility. This requires relatively coplanar polymer backbone with close intermolecular interactions and ordering. Key to these technologies is the high-quality interface between tissue and electronics. Organic electronic materials share a similar chemical "nature" with biological molecules, can be engineered on various forms, including hydrogels that have Young's moduli similar to soft tissues and are ionically conducting. Furthermore, the structure of organics can be tuned through synthetic chemistry, and their biological properties can be controlled using a variety of functionalization strategies. Finally, organics electronic materials can be integrated with a variety of mechanical supports giving rise to devices with form factors (conformable, stretchable, fibrous, 3D porous) that enable integration with biological systems.