Charge Sensitivity Control of Potentiometric Nanobiosensors

该项目的重点是对纳米生物传感器的电荷检测机制有更深入的了解。显然，传感器表面在电位型生物传感器的发展中起着关键作用。我们的目标是调查、控制和了解各自的传感器表面。关于表面参数α(对应于pH值/灵敏度)对于生物分子电荷敏感性的作用，目前还缺乏系统的实验工作来探索理论预测。此外，文献中往往忽略了非常基本的电化学设计原理。我们正计划开发一种新的电位型纳米生物传感器。虽然可以常规地进行电位测量，但由于大量伪影也可能引起的电位漂移的矛盾性质，通常会出现并发症。因此，我们将开发一种基于超长纳米线的差动传感器装置，使用相同的纳米线作为传感器和参考元件。这两个纳米线场效应晶体管是用两个不同的表面参数α制造的，因此有两个不同的电荷灵敏度。这样做，大多数不受欢迎的干扰将被系统性地抵消。这一新概念的有效性和可行性应在该项目中进行探索。此外，我们的目标是深入了解电位生物传感器的一般操作以及纳米线生物传感器可能受到的影响。这需要系统地描述和理解绝缘体/电解液界面，最后仔细分析单个纳米线FET的传感器响应。

The project is focused to get a deeper knowledge on the nanobiosensor charge detection mechanism. It is apparent that the sensor surface plays the key role in the development of potentiometric biosensors. We are aiming at investigating, controlling and understanding the respective sensor surfaces. There is a considerable lack of systematic experimental work that explores the theoretical predictions on the role of the surface parameter α (corresponding to pH value/sensitivity) with respect to biomolecule charge sensitivity. In addition, very basic electrochemical design principles are often ignored in literature. We are planning to develop a new concept of a potentiometric nanobiosensor. While the potentiometric measurements can be routinely performed, complications arise usually due to the ambivalent nature of the potential shift that can be caused also by a multitude of artifacts. Therefore, we will develop a differential sensor setup based on ultra-long nanowires using the same nanowire as sensor and reference element. The two nanowire field-effect transistors (FET) are fabricated using two different surface parameters α and hence two different charge sensitivities. Doing so, most undesired disturbances will systematically cancel out. The validity and feasibility of this new concept should be explored within this project. Further, we aim to gain insight into the operation of potentiometric biosensors in general and how nanowire biosensors are possibly affected. This requires a systematically characterized and well understood insulator/electrolyte interface and finally a careful analysis of the sensor responses from individual nanowire FETs.