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装置的关键部件，它们渗透到我们的生活中，是人们研究的热点。为了进一步扩大其应用领域并提高其性能，需要开发新的电极，以解决我们社会中出现的众多挑战。一个例子是发展中国家生活方式的变化和世界范围内人口的迅速老龄化（特别是在发达国家），这就需要在生物传感中使用电化学装置，以迅速发展连续监测和护理点装置。这是至关重要的，因为它将导致更好的预防保健和早期诊断，减轻卫生保健系统日益不可持续的负担。糖尿病就是一个例子，在这种情况下，电化学传感器被用于监测，目前的挑战是将它们提升到持续监测能力，以解决这种疾病日益普遍的问题。在这些不同的应用范围内，电极的组成、几何形状和尺寸是决定电化学器件性能的关键因素。这是因为电极的功能是基于大量的过程，包括质量传递，电子传递和离子流，到或接近电极表面，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作纳米电极，并研究它们的电化学性能。纳米颗粒将形成一个分支的一维分支结构，然后转化为连续的纳米电极。为了便于集成到器件中，纳米电极的长度尺度将以微米为单位，而其其他尺寸将限制在100纳米尺度。与宏观尺度电极相比，这些纳米尺度的电极将确保快速的传质到电极表面，高信噪比，更好的灵敏度和更快的稳定时间。小尺寸的天平也将使其在有限的功耗和少量分析物的情况下使用，这对于检测体液（如泪液、汗液和唾液）至关重要。因此，它们将适用于可穿戴电子设备，用于连续监测体液中的生物分子。该项目将重点研究使用不同的离子进行纳米粒子的自组装，随后将其转化为连续的纳米电极，将纳米电极集成为电化学装置，并测试其与宏观尺度电极相比的性能特征。

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.