Adsorption and Desorption of Chiral Molecules on Gold Substrate in Magnetic Fields

The chiral-induced spin selectivity (CISS) effect refers to the fact that when electrons transit through a chiral molecule (or structure), the chiral potential leads to an effective magnetic field in the rest frame of the electron that acts on the electron spin, providing a preference for the transmission of one electron spin orientation over the other. Because of the CISS effect, the interaction between a magnetized surface and a chiral molecule will depend on the enantiomer and on the magnetization direction of the magnetized substrate. This work aims to better understand the interaction between a ferromagnetic surface and chiral molecules and use the knowledge to establish a method of enantiomer separation. An electrochemical quartz crystal microbalance (EQCM) is used to study the electrochemical adsorption and desorption for different enantiomers of a chiral molecule, cysteine, onto ferromagnetic substrates under an external magnetic field, both thermodynamically and kinetically. The results show that the kinetics for adsorption and desorption of a chiral molecule depends on the magnetization direction of the surface