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

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.