Hwang Kee Young, Brown Dakota, Attanayake Supun B, Luu Dan, Nguyen Minh Dang, Lee T Randall, Phan Manh-Huong
Laboratory for Advanced Materials and Sensors, Department of Physics, University of South Florida, Tampa, FL 33620, USA.
Department of Chemistry and the Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA.
Biosensors (Basel). 2025 Feb 17;15(2):116. doi: 10.3390/bios15020116.
Magnetic nanoparticles are extensively utilized as markers/signal labelling in various biomedical applications. Detecting and distinguishing magnetic signals from similarly sized moving magnetic nanoparticles in microfluidic systems is crucial yet challenging for biosensing. In this study, we have developed an original method to detect and differentiate magnetic signals from moving superparamagnetic (SPM) and ferrimagnetic (FM) nanoparticles of comparable sizes. Our approach utilizes a highly sensitive magnetic-coil-based sensor that harnesses the combined effects of giant magnetoimpedance (GMI) and an LC-resonance circuit, offering performance superior to that of conventional GMI sensors. Iron oxide nanoparticles, which have similar particle sizes but differing coercivities (zero for SPM and non-zero for FM) or similar zero coercivities but differing particle sizes, flow through the magnetic coil at controlled velocities. Their distinct effects are analyzed through changes in the complex impedance of the sensing system. Our findings provide a unique pathway for utilizing SPM and FM nanoparticles as innovative magnetic markers to identify specific biological entities, thereby expanding their potential applications.
磁性纳米颗粒在各种生物医学应用中被广泛用作标记物/信号标签。在微流体系统中检测和区分来自大小相似的移动磁性纳米颗粒的磁信号对于生物传感至关重要，但也具有挑战性。在本研究中，我们开发了一种原始方法来检测和区分来自大小相当的移动超顺磁性（SPM）和亚铁磁性（FM）纳米颗粒的磁信号。我们的方法利用了一种基于高灵敏度磁线圈的传感器，该传感器利用了巨磁阻抗（GMI）和LC谐振电路的综合效应，其性能优于传统的GMI传感器。具有相似粒径但矫顽力不同（SPM为零，FM不为零）或相似零矫顽力但粒径不同的氧化铁纳米颗粒以受控速度流过磁线圈。通过传感系统复阻抗的变化来分析它们的不同影响。我们的研究结果为利用SPM和FM纳米颗粒作为创新的磁性标记物来识别特定生物实体提供了一条独特途径，从而扩展了它们的潜在应用。
