Magnetic Beads Amplification based Biosensing System

检测用作‘磁性标签’的小浓度的200纳米以下的SPBS(超顺磁珠)对于快速、高度敏感和便携式的护理点治疗(POCT)至关重要。目前，磁阻(MR)生物传感器被用于检测高浓度的SPBS，但由于这些电子器件的固有噪声，这种方法不适合于监测少量的200 nm以下的SPBS。为了克服传统MR传感器的这一局限性，本研究开发了一种简单的方法，通过利用微米级SPBS在纳米靶上的磁感应自组装来检测直径小于200 nm的小浓度SPBS用于生物传感。这种方法能够在光学显微镜下监测纳米磁珠对微米级SPB的磁感应自组装的捕获，以及使用霍尔生物传感器对来自其他方式无法检测的纳米SPB目标的信号的物理放大，而不使用交流磁场或锁定检测，从而能够生产适用于广泛应用的简单POCT方案。

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.