Institute of Physics, Ecole Polytechnique Federale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
Phys Chem Chem Phys. 2020 Jan 22;22(3):997-1002. doi: 10.1039/c9cp04681j.
Chirality-induced spin selectivity is evidenced by exciting the spin resonance of radicals in an electrochemical cell where the working electrode is covered with a chiral self-assembled monolayer. Because the electron transfer to and from the paramagnetic radical is spin dependent, the electrochemical current changes at resonance. This electrically-detected magnetic resonance (EDMR) is monitored by a lock-in detection based on electrode voltage modulation, at a frequency that optimizes the sensitivity of the differential conductance to the electrode charge transfer process. The method is validated using p-doped GaAs electrodes in which the conduction band electrons are hyperpolarized by a well-known method of optical spin pumping with circularly polarized light. Gold electrodes covered with peptides consisting of 5 alanine groups (Al5) present a relative current change of up to 5 × 10-5 when the resonance condition is met, corresponding to a spin filtering efficiency between 6 and 19%.
手性诱导的自旋选择性表现在电化学池中激发自由基的自旋共振，其中工作电极覆盖有手性自组装单层。由于顺磁自由基的得失电子是自旋相关的，因此在共振时电化学电流会发生变化。这种电检测磁共振（EDMR）通过基于电极电压调制的锁定检测来监测，调制频率优化了差分电导对电极电荷转移过程的灵敏度。该方法使用 p 型掺杂 GaAs 电极进行了验证，其中通过众所周知的圆偏振光光学自旋泵浦方法使导带电子高度极化。当满足共振条件时，由 5 个丙氨酸组成的肽（Al5）覆盖的金电极的相对电流变化高达 5×10-5，对应于 6%至 19%之间的自旋过滤效率。
