Electron-Spin-Resonance Dipstick.
Electron-Spin-Resonance Dipstick.
复制标题
电子自旋共振试纸尺。
DOI：
10.1021/acs.analchem.8b00917
复制
发表时间：
2018
影响因子：
7.4
通讯作者：
Blank,Aharon
中科院分区：
文献类型：
--
作者：
Zgadzai,Oleg;Twig,Ygal;Wolfson,Helen;Ahmad,Rizwan;Kuppusamy,Periannan;Blank,Aharon
电子自旋共振（ESR）是一种强大的分析技术，用于检测、定量和表征顺磁性物质，范围从稳定的有机自由基和晶体中的缺陷到气态氧。传统上，ESR需要使用复杂的仪器，包括一个大磁铁和一个微波谐振器，样品被放置在其中。在这里，我们提出了一种替代现有方法的方法，通过反转典型的测量拓扑结构，即将ESR磁体和谐振器放置在样品内部，而不是相反。这项新的开发依赖于一种新型的独立ESR传感器，直径仅为2 mm，长度为3.6 mm，其中包括一个小型永磁体组件和一个微小的（尺寸为1.1 mm）谐振器，用于在2.6 GHz的频率下进行自旋激发和检测。传感器的自旋灵敏度已被测量为1011 spins/kHz，其浓度灵敏度为10.1 mM，使用的参考样品的测量体积仅为1010 nL。我们的新方法可以应用于监测氧分压在体外和体内通过其与另一个稳定的自由基的顺磁相互作用，以及通过化学过程中产生的自由基的简单的在线定量检测反应容器和电化学电池。
Electron spin resonance (ESR) is a powerful analytical technique used for the detection, quantification, and characterization of paramagnetic species ranging from stable organic free radicals and defects in crystals to gaseous oxygen. Traditionally, ESR requires the use of complex instrumentation, including a large magnet and a microwave resonator in which the sample is placed. Here, we present an alternative to the existing approach by inverting the typical measurement topology, namely placing the ESR magnet and resonator inside the sample rather than the other way around. This new development relies on a novel self-contained ESR sensor with a diameter of just 2 mm and length of 3.6 mm, which includes both a small permanent magnet assembly and a tiny (∼1 mm in size) resonator for spin excitation and detection at a frequency of ∼2.6 GHz. The spin sensitivity of the sensor has been measured to be ∼1011spins/√Hz, and its concentration sensitivity is ∼0.1 mM, using reference samples with a measured volume of just ∼10 nL. Our new approach can be applied for monitoring the partial pressure of oxygen in vitro and in vivo through its paramagnetic interaction with another stable radical, as well as for simple online quantitative inspection of free radicals generated in reaction vessels and electrochemical cells via chemical processes.