Ion mediated self-assembly of nanoparticles to develop nanoelectrodes

电极是电池、生物传感器、电催化系统和超级电容器等电化学设备中的关键部件，这些设备渗透到我们的生活中，是人们深入研究的对象。需要开发新的电极，以进一步扩大其应用领域，并提高其性能，以应对我们社会中出现的众多挑战。一个例子是发展中国家不断变化的生活方式和世界范围内迅速老龄化的人口(特别是在发达国家)，这就要求在生物传感中使用电化学设备以开发连续监测和护理点设备。这一点至关重要，因为它将带来更好的预防性护理和早期诊断，减轻卫生保健系统日益难以为继的负担。糖尿病就是一个例子，说明了这种情况，其中使用电化学传感器进行监测，目前的挑战是将它们提高到持续监测的能力，以应对这种疾病日益普遍的情况。电极的组成、几何形状和大小是决定电化学设备在这些不同应用范围中性能的关键因素。这是因为电极的功能建立在一系列过程的基础上，这些过程涉及离子到电极表面或靠近电极表面的质量传递、电子传递和流动，因此受到这些因素的影响。在这个项目中，我的目标是利用纳米粒子与目标金属离子的自组装来制造纳米电极，并研究其电化学性能。纳米粒子将形成一维分支结构，然后转化为连续的纳米电极。纳米电极的长度尺度将以微米为单位，以便于集成到器件中，而其其他尺寸将被限制在100纳米尺度。这些纳米尺度的电极与宏观尺度的电极相比，将确保快速的电极表面传质速度、高信噪比、更好的灵敏度和更快的稳定时间。小尺寸的刻度还将使它们能够以有限的功耗和较小的分析物体积使用，这对于检测体液中的泪水、汗液和唾液至关重要。因此，它们将适合应用于可穿戴电子设备，以连续监测体液中的生物分子。该计划将专注于研究使用不同的离子进行纳米颗粒的自组装，将其随后转化为连续的纳米电极，将纳米电极作为电化学装置进行集成，并进行测试，以表征其与宏观电极相比的性能。

Electrodes are critical components in electrochemical devices such as batteries, bio-sensors, electro-catalytical systems and supercapacitors, which permeate our life and are subject of intense research. Development of new electrodes is required to further expand their areas of application and also enhance their performance, to addresses the multitude of challenges that are arising in our society. A case is the changing life styles in developing countries and a rapidly ageing population world-wide (specifically in developed countries), which necessitates the use of electrochemical devices in bio-sensing to be rapidly advanced for developing continuous monitoring and point of care devices. This is vital as it will lead to better preventive care and early diagnosis, reducing the increasingly unsustainable burden on health care system. Diabetes is an example that illustrates this scenario, where electrochemical sensors are used for monitoring and the current challenge is to advance them to continuous monitoring capability to tackle the growing prevalence of this condition. The composition, geometry and the size of the electrode are the critical factors that determine the performance of electrochemical devices in these diverse ranges of applications. This is because the functioning of the electrode is based on a multitude of processes that involve mass transfer, electron transfer and flow of ions, to or near the electrode surface and hence are affected by these factors. In this program my objective is to use self-assembly of nanoparticles with targeted metal ions to make nanoelectrodes and study their electrochemical performance. The nanoparticles will form a branched 1-D branched structure that will then be transformed into a continuous nanoelectrode. The length scale of the nano-electrode will be in microns for facile integration into devices, while its other dimensions will be limited to 100 nm scale. These nanometer size scales compared to macro scale electrodes will ensure a rapid rate of mass transfer to the electrode surface, high signal to noise ratio, better sensitivity and faster stabilization times. The small size scales will also enable their use with limited power consumption and small analyte volumes that is critical for detection in body fluids such as tear, sweat and saliva. Hence they will be suitable for application in wearable electronics for continuous monitoring of biomolecules in body fluids. The program will focus on researching the use of different ions for the self-assembly of the nanoparticles, their subsequent transformation into a continuous nanoelectrode, the integration of the nanoelectrode as an electro-chemical device and testing to characterize its performance compared to a macro scale electrodes.