Magnetic Beads Amplification based Biosensing System

检测用作“磁性标签”的小浓度的小于200 nm尺寸的SPB（超顺磁珠）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大浓度的SPB，但是由于这些电子设备的固有噪声，这种方法不适合于监测少量的亚200nm SPB。为了克服传统MR传感器的这种局限性，本研究已经导致了一个简单的程序的开发，用于检测小浓度的子200 nm直径的SPBs的生物传感，通过利用磁诱导自组装的微米尺寸的SPBs到纳米目标。这种方法能够在光学显微镜下监测纳米磁珠对微米尺寸SPB的磁诱导自组装的捕获，以及使用霍尔生物传感器对来自原本不可检测的纳米SPB目标的信号的物理放大，而不使用交流磁场或锁定检测的应用，从而能够产生用于广泛应用的简单POCT协议。

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.