该文介绍了基于超顺磁纳米颗粒的弛豫时间(T2)传感技术及其在生化分析应用中的研究进展.在均匀磁场中,超顺磁纳米颗粒状态的变化(分散或聚集)会改变磁场的均匀度进而引起周围水分子质子弛豫时间的改变,即磁弛豫时间传感效应.磁颗粒经表面修饰后与给体/受体偶联形成磁传感探针,当与待测物发生特异性反应后,引起介质磁颗粒聚集状态改变,使相应弛豫时间改变,变化程度与待测分子含量呈相关关系,从而实现待测物的传感分析.该传感技术结合纳米技术、核磁共振技术和生物免疫学技术,不依赖光信号,耗样量少,具有前处理简单、快速、灵敏、无损、适于现场检测等优点,在临床诊断、环境分析、食品安全、公共卫生安全和生物大分子相互作用研究等领域有广阔的应用潜力.%The magnetic relaxation switches( MRS) technology based on superparamagnetic nanopar-ticles(SMP) and their applications in biochemical analysis were introduced in this paper. In homogenous magnetic field of miniaturized nuclear magnetic, the dispersed and aggregated states of SMP produce local inhomogeneities in the applied magnetic field, resulting in the decrease or increase in the spin ± spin relaxation time( T2) of surrounding water molecules, which is called magnetic relaxation time ( MRS) sensing effect. The magnetic particles binding with specific molecules can act as magnetic relaxation switches (MRS) when they coupled specially with target analytes. In MRS assays, the presence of an analyte causes the particles to transition between dispersed and clustered states and affects the T2 relaxation times of surrounding water molecules. Compared with the conventional immu-nological methods, MRS assay is more sensitive, simple and time-saving due to its combination of nanobiotechnology, nuclear magnetic resonance and immunoassay. Predictably, it has a remarkable application potential in the fields of medical diagnosis, environmental monitoring, food safety analysis, public healthy security and molecular interactions study, etc.
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