Department of Neuroscience, The Alfred Centre, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia.
Department of Electrical and Electronic Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
Sensors (Basel). 2020 Sep 12;20(18):5213. doi: 10.3390/s20185213.
Biosensors based on magneto-impedance (MI) effect are powerful tools for biomedical applications as they are highly sensitive, stable, exhibit fast response, small in size, and have low hysteresis and power consumption. However, the performance of these biosensors is influenced by a variety of factors, including the design, geometry, materials and fabrication procedures. Other less appreciated factors influencing the MI effect include measuring circuit implementation, the material used for construction, geometry of the thin film sensing element, and patterning shapes compatible with the interface microelectronic circuitry. The type magnetic (ferrofluid, Dynabeads, and nanoparticles) and size of the particles, the magnetic particle concentration, magnetic field strength and stray magnetic fields can also affect the sensor sensitivity. Based on these considerations it is proposed that ideal MI biosensor sensitivity could be achieved when the sensor is constructed in sandwich thick magnetic layers with large sensing area in a meander shape, measured with circuitry that provides the lowest possible external inductance at high frequencies, enclosed by a protective layer between magnetic particles and sensing element, and perpendicularly magnetized when detecting high-concentration of magnetic particles.
基于磁阻抗（MI）效应的生物传感器是生物医学应用的有力工具，因为它们具有高灵敏度、稳定性、快速响应、体积小、滞后和功耗低等优点。然而，这些生物传感器的性能受到多种因素的影响，包括设计、几何形状、材料和制造工艺。其他不太受关注的影响 MI 效应的因素包括测量电路的实现、用于构建的材料、薄膜传感元件的几何形状以及与接口微电子电路兼容的图案形状。磁性（铁磁流体、Dynabeads 和纳米颗粒）和颗粒的大小、颗粒的浓度、磁场强度和杂散磁场也会影响传感器的灵敏度。基于这些考虑，提出了当传感器采用具有大感应面积的曲折形状的三明治厚磁层构建，用提供最低外部电感的电路在高频下进行测量，用保护层将磁颗粒和传感元件隔开，并且在检测高浓度磁颗粒时垂直磁化时，理想的 MI 生物传感器灵敏度可以实现。
