Investigation of novel magnetic sensors in combination with magnetic particles towards the development of a point of care disease diagnostic platform

分子诊断学已经成为一种很有前景的疾病识别方法，它通过量化特定生物分子的存在来指示人类疾病。据推测，一个能够从体液样本中快速检测一组生物标志物的平台将给医疗保健带来革命性的变化，使快速准确的诊断、疾病分期、适当的治疗处方和患者对护理的反应分析成为可能。与日立公司合作，我们的目标是开发这样一个平台。为此，我们正在开发一种新型的磁性传感器，能够高精度地检测大量的磁性纳米颗粒。这些颗粒在本文中通常被称为生物标签，它们被化学功能化，以便当添加到体液样本中时，它们附着在特定的生物分子上。随后的颗粒计数给出了目标生物分子浓度的测量，并可用于推断相关疾病的存在、缺失或进展阶段。在该项目的初始阶段，探索了新型磁性传感器和生物标签的各种组合。经过多方面的研究，发现一种新型的霍尔传感器与亚铁磁性纳米盘相结合是最有前途的，这种结构已经被选中进行广泛的研究。将用作生物标签的亚铁磁性纳米盘是使用研究小组开发的新制造技术生产的。采用各种技术来表征颗粒的磁性和物理性质。与市售产品相比，这些颗粒的主要优势在于其磁性的可调性，这使我们能够实现对其在流体中运动的高水平控制。为了最大化磁信号，人们正在研究是否可以控制颗粒落在传感器表面的位置，以及是否可以以理想的方式组装颗粒。使用在Python语言中执行的有限差分模拟和COMSOL相结合的方法，正在研究磁性传感器检测这些颗粒的潜力。这些模拟的中心目标是优化传感器设计的各个方面，以便最大化磁性纳米颗粒的检测信号，并为传感器制造提供信息。

Molecular diagnostics has emerged as a promising approach to the identification of illness through quantifying the presence of specific biomolecules, indicative of human disease. It is hypothesised that a platform capable of the rapid detection of a panel of biomarkers from a sample of bodily fluid will revolutionise healthcare, enabling quick and accurate diagnostics, disease staging, appropriate treatment prescription and the analysis of patient response to care. In collaboration with Hitachi, we aim to develop such a platform.To this end, we are working on the development of a novel magnetic sensor, capable of detecting with high accuracy, large numbers of magnetic nanoparticles. These particles, often referred to as bio-tags in this context, are chemically functionalised such that they attach to specific biomolecules when added to a sample of bodily fluid. Subsequent enumeration of the particles gives a measure of the concentration of the target biomolecule, and can be used to infer the presence, absence or stage of progression of the associated disease. During the initial stages of the project, various combinations of novel magnetic sensors and bio-tags were explored. Following much consideration, it was found that a novel Hall sensor in combination with ferrimagnetic nano-disks showed the most promise, and this architecture has been selected for extensive investigation. The ferrimagnetic nano-disks which are to be used as bio-tags are produced using novel fabrication techniques developed in the research group. Various techniques are employed to characterise the magnetic and physical properties of the particles. The central advantage of these particles over commercially available options is the tunability of their magnetic properties, which enables us to achieve a high level of control of their motion within a fluid. It is being investigated whether the positions at which the particles land on the sensor surface can be controlled, and whether the particles can be assembled in desirable ways, in order to maximise magnetic signal.Using a combination of finite difference simulations executed in Python, and COMSOL, the potential of the magnetic sensor to detect these particles is being investigated. The central aim of these simulations is to optimise various aspects of the sensor design, in order to maximise the detected signal of the magnetic nanoparticles and inform sensor fabrication.