Using Single-Spin ESR and NMR to Identify Amino Acids and Phosphorylated Derivatives

by Mr. Yahel Tzuriel

Physics department, BGU
at Condensed Matter Seminar

Mon, 15 Jul 2024, 11:40
Sacta-Rashi Building for Physics (54), room 207


Electron spin resonance (ESR) and nuclear magnetic resonance (NMR) are both powerful techniques used in modern chemistry, relying on the detection of the electron and nuclear magnetic transitions, respectively. ESR spectroscopy can be used to identify molecules and elucidate molecular conformations but is restricted to the study of radical, paramagnetic species. NMR spectroscopy can accomplish similar feats but has a higher level of generality due to the abundance of spin-bearing nuclei in organic molecules, such as hydrogen. For this reason, NMR techniques see widespread use in chemistry, physics, biology, medicine, material science, and recently quantum computing.
The scanning tunneling microscope (STM) is an imaging instrument which leverages the possibility of electrons to quantum tunnel through a finite energy barrier to scan molecular surfaces with atomic resolution. In recent years, a method was developed for detecting ESR and NMR spectra of molecules through the tunneling current measured by the STM. This method can provide similar information to that obtained by macroscopic ESR and NMR, only for a specific, single molecule.
This present thesis is dedicated to the study of L-threonine and L-tyrosine amino acids deposited on an Au(111) substrate using the ESR-STM and NMR-STM techniques. In addition, the phosphorylated derivative of tyrosine, O-phospho-L-tyrosine is studied, and compared to tyrosine. Phosphorylation of amino acids in proteins is a common covalent modification used by organisms for enzyme regulation, as well as for intracellular and extracellular signaling. The work showcases the potential of both ESR-STM and NMR-STM methods to study biochemical systems, providing insights into the structure and composition on the single molecule level

Created on 04-07-2024 by Naamneh, Muntaser (mnaamneh)
Updaded on 15-07-2024 by Naamneh, Muntaser (mnaamneh)