Magnetic Beads Amplification based Biosensing System

用于“磁性标签”的小浓度spb（超顺磁珠）的检测对于快速、高灵敏度和便携式护理点治疗（POCT）至关重要。目前，磁阻（MR）生物传感器用于检测高浓度的SPBs，但由于这些电子设备的固有噪声，这种方法不适合监测少量的200nm以下的SPBs。为了克服传统MR传感器的这一局限性，本研究开发了一种直接的方法，通过利用微米大小的spb在纳米目标上的磁诱导自组装来检测小浓度的低于200纳米直径的spb，用于生物传感。该方法能够在光学显微镜下通过纳米磁珠监测微米级spb的磁诱导自组装捕获，并使用霍尔生物传感器对来自其他不可检测的纳米spb目标的信号进行物理放大，而无需使用交流磁场或锁定检测，从而能够生产简单的POCT协议，用于广泛的应用。

Detection of small concentrations of sub-200 nm sized SPBs (superparamagnetic beads) that are used as ‘magnetic labels’ is critical for rapid, highly sensitive, and portable point of care treatment (POCT). Currently, magnetoresistive (MR) biosensors are used for the detection of large concentrations of SPBs but such an approach is not suitable for monitoring small numbers of sub-200nm SPBs due to the intrinsic noise of these electronic devices. In order to overcome this limitation of conventional MR sensors, this research has led to the development of a straightforward procedure for detecting small concentrations of sub-200-nm-diameter SPBs for biosensing by exploiting magnetically induced self-assembly of micrometer sized SPBs onto nanometer targets. This approach enables the monitoring the capture of magnetically induced self-assembly of micrometer sized SPBs by nanometer magnetic beads under an optical microscope, and the physical amplification of the signal from otherwise undetectable nano-SPB targets using Hall biosensors without using the application of ac magnetic fields or lock-in detection, thereby enabling the production of a simple POCT protocol for a wide range of applications.