Room: Park Tower 8228
Jovian Lazare - Clark Atlanta University
Co-Author(s): Ravyn Robinson, Clark Atlanta University, Atlanta, GA; Diamond Boddie, Clark Atlanta University, Atlanta, GA; Tandabany Dinadayalane Clark Atlanta University, Atlanta, GA
The hypothesis is that the strength of binding affinity of different aliphatic α-amino acids relates to the number of noncovalent interactions between the amino acid and graphene. Quantum chemical calculations at M06-2X/6-31G(d) level were performed to understand the binding of naturally occurring aliphatic α-amino acids (glycine, alanine, valine, leucine, isoleucine, cysteine, methionine, aspartic acid, glutamic acid, lysine, arginine, serine, threonine, asparagine, and glutamine) individually with two different sizes of graphene models. After performing conformational analysis for these fifteen amino acids using Merck Molecular Force Field (MMFF), geometries of all conformers were optimized at the HF/6-31G(d) level and then up to 300 conformers were chosen to be optimized at the M06-2X/6-31G(d) level using Spartan ’18 program package. The most stable conformer of each of the two distinct hydrogen bonding backbone configurations was selected at the M06-2X/6-31G(d) level for further calculations of their binding with graphene. Each conformer was used to build complexes with graphene by considering different possible binding modes. All complexes were fully optimized using M06-2X/6-31G(d) level. Binding energies with and without basis set superposition error (BSSE) correction were calculated and analyzed. Our study reveals that multiple C-H…pi, N-H…pi, and/or O-H…pi interactions play important role in determining the binding strength of each amino acid on graphene surface. Our study also reveals that strong intramolecular hydrogen bonding in the backbone facilitates the strong binding affinity of amino acids with graphene. The data obtained from our computational study may be helpful for force field development and for future experiments on non-covalent interactions of amino acids with graphene. The future direction is to perform calculations of HOMO-LUMO energy gaps and find relationship with binding affinities.
Funder Acknowledgement(s): We acknowledges the National Science Foundation (NSF) for the financial support through HBCU-UP Research Initiation Award (Grant number 1601071). Extreme Science and Engineering Discovery Environment (XSEDE) is also acknowledged for the computational resources.
Faculty Advisor: Dr. Dinadayalane Tandabany, email@example.com
Role: Majority of the calculations and analysis.