Wang Haoyu, Wang Biaobiao, Bai Jinsuo, Yao Penglong, Guo Xing, Ge Yang, Sang Shengbo, Dong Xiushan, Dong Zhao
Shanxi Key Laboratory of Artificial Intelligence & Micro Nano Sensors, Taiyuan University of Technology, Taiyuan, 030024, China.
Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan, 030024, China.
Mikrochim Acta. 2025 Aug 14;192(9):590. doi: 10.1007/s00604-025-07386-5.
Surface stress-based biosensors exhibit excellent performance in detecting high concentrations of biomolecules; however, their sensitivity at low concentrations is often limited by insufficient deformation caused by weak binding-induced signals. To overcome this limitation, we propose an actively driven biosensor based on a multilayered heterogeneous magnetic film (PDMS/NiFe/FeMn), which achieves synergistic amplification of surface stress and geometric deformation under magnetic field modulation, thereby breaking through the sensitivity bottleneck of conventional designs. The sensor architecture leverages the high magnetic permeability of NiFe and the magnetostrictive effect of FeMn to construct a magneto-mechanical coupling interface: the NiFe layer efficiently transduces magnetic field energy, while the FeMn layer actively deforms to amplify the surface stress generated by target binding (Tau protein). A flexible PDMS substrate further releases mechanical strain, establishing a dual amplification mechanism of "biorecognition-magnetically driven deformation-electrical signal output." The experimental results show that the detection limit of this sensor for the Alzheimer's disease biomarker Tau protein is as low as 25.7 pM. Compared with self-made non-magnetic sensors, the sensitivity has been significantly improved, and it maintains stable performance in artificial cerebrospinal fluid. This approach, based on active signal amplification through heterogeneous magnetic film coupling, offers a new paradigm for the ultrasensitive detection of low-abundance biomarkers in complex biofluids and holds significant promise for the early diagnosis of neurodegenerative diseases.
基于表面应力的生物传感器在检测高浓度生物分子方面表现出色；然而，它们在低浓度下的灵敏度往往受到弱结合诱导信号引起的变形不足的限制。为了克服这一限制，我们提出了一种基于多层异质磁性薄膜（PDMS/NiFe/FeMn）的主动驱动生物传感器，该传感器在磁场调制下实现了表面应力和几何变形的协同放大，从而突破了传统设计的灵敏度瓶颈。该传感器架构利用NiFe的高磁导率和FeMn的磁致伸缩效应构建了一个磁机械耦合界面：NiFe层有效地转换磁场能量，而FeMn层主动变形以放大由目标结合（Tau蛋白）产生的表面应力。柔性PDMS基板进一步释放机械应变，建立了“生物识别-磁驱动变形-电信号输出”的双重放大机制。实验结果表明，该传感器对阿尔茨海默病生物标志物Tau蛋白的检测限低至25.7 pM。与自制的非磁性传感器相比，灵敏度有了显著提高，并且在人工脑脊液中保持稳定的性能。这种基于异质磁性薄膜耦合的主动信号放大方法为复杂生物流体中低丰度生物标志物的超灵敏检测提供了一种新范式，对神经退行性疾病的早期诊断具有重要意义。
