Chuang Han-Sheng, Pham Thi Thanh Huong, Chou Yu-Hsuan, Huang Chi-Ying F, Tu Ting-Yuan, Yang Tai-Hua, Wang Jhih-Cheng
Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan.
Front Bioeng Biotechnol. 2025 Apr 25;13:1565479. doi: 10.3389/fbioe.2025.1565479. eCollection 2025.
Detecting small biological molecules is challenging due to their tiny size, vulnerability, and low concentrations in samples. Bead-based biosensors are frequently used as probes but require tedious processing or expensive instruments. By combining magnetic Janus particles (MJPs) and an electromagnetic device, we successfully built an active diagnostic tool for the rapid sensing of small extracellular vesicles (sEVs). We observed that the system can be altered according to particle size, distance between MJPs and the electromagnet, fluid viscosity, and magnetic field strength. By modulating the driving frequency from low (3 Hz) to high (22 Hz), the MJPs gradually lose their synchrony with the external magnetic field after exceeding a certain threshold termed cutoff frequency. The novel sEVs sensing MJP system was characterized through both theoretical and experimental methods, showing reliable performance in identifying the cancer cell OECM-1-derived sEVs using the CD63 surface marker. A decent sEV concentration of 2.9 × 10 particles mL was reached and a high specificity was also observed. This approach opens a door for the realization of disease screening, such as cancer, using intact exosomes from body fluids without sophisticated processing. These findings provide insight into the future use of MJPs as point-of-care testing tools for liquid biopsy.
由于生物小分子尺寸微小、易受破坏且在样本中的浓度较低，检测它们具有挑战性。基于珠子的生物传感器经常被用作探针，但需要繁琐的处理过程或昂贵的仪器。通过将磁性Janus粒子（MJP）与电磁装置相结合，我们成功构建了一种用于快速检测小细胞外囊泡（sEV）的活性诊断工具。我们观察到，该系统可根据粒子大小、MJP与电磁铁之间的距离、流体粘度和磁场强度进行改变。通过将驱动频率从低（3Hz）调制到高（22Hz），MJP在超过某个称为截止频率的阈值后逐渐与外部磁场失去同步。通过理论和实验方法对新型sEV传感MJP系统进行了表征，结果表明该系统在使用CD63表面标志物识别癌细胞OECM-1衍生的sEV时具有可靠的性能。达到了2.9×10个粒子/毫升的适宜sEV浓度，并且还观察到了高特异性。这种方法为利用来自体液的完整外泌体实现疾病筛查（如癌症筛查）打开了一扇门，而无需复杂的处理。这些发现为未来将MJP用作液体活检的即时检测工具提供了思路。
