Magnetic nanobeads have been widely used for magnetic separation, target labeling and signal amplification in the development of various biosensors. This review summarized (1) the basic knowledge of magnetic nanobeads, including physical structure, chemical characteristics and surface modification; (2) the development and applications of magnetic separation, from the earliest conventional magnetic separation, to high gradient magnetic separation, then to magnetophoretic separation and magnetic continuous-flow separation, finally to the latest magnetic grid separation; and (3) recent advances and applications of magnetic nanobead based biosensors, where the magnetic nanobeads work as either detection signal for electromagnetic biosensors, magnetic lateral flow biosensors and magnetic relaxation switching biosensors, or signal amplifying tag for electrochemical biosensors, QCM biosensors and SPR biosensors, or both. Besides, the important issues and future trends for magnetic nanobead based separation and biosensor were also discussed and summarized.

在各种生物传感器的开发中，磁性纳米珠已广泛用于磁性分离，目标标记和信号放大。本文综述（1）磁性纳米珠的基本知识，包括物理结构，化学特性和表面改性；（2）磁选的发展和应用，从最早的常规磁选，到高梯度磁选，再到磁致分离和磁连续流分离，最后到最新的磁栅分离；（3）基于磁性纳米珠的生物传感器的最新进展和应用，其中磁性纳米珠可作为电磁生物传感器，磁性横向流生物传感器和磁性弛豫转换生物传感器的检测信号，或用于电化学生物传感器，QCM生物传感器和SPR生物传感器或两者的信号放大标签。此外，还讨论并总结了基于磁性纳米珠的分离和生物传感器的重要问题和未来的趋势。