NSF Award
1833019
Nontechnical Description <br/> This project focuses on elucidating fundamental science on the surfaces of amino acids by comparing characterizations under carefully controlled conditions with those closer to real-world conditions. In line with NSF's mission, this project will lead to a deeper understanding of how small, prebiotic molecules interact with surfaces and participate in the emergence of biologically applicable precursors. On a fundamental level, this project will study how amino acid molecules interact and how those interactions correlate to biologically relevant structures like proteins. Importantly, the association of single-molecule studies performed on a high-end microscope (low temperature, high vacuum) with studies performed on a less-ideal microscope (room temperature, typical atmospheric pressure) is both novel and essential to studying biologically relevant systems. While single molecule studies are often performed in pristine conditions, it is rare that those studies are combined with the same systems in the real-world. Research outcomes will make significant contributions to our understanding of prebiotic molecules and the evolution of those molecules on metallic surfaces. The findings of this research will be used at educational events to demonstrate how fundamental science can be used to make broader predictions about amino acids and the beginning of biologically-active molecules on this planet. <br/><br/>Technical Description<br/> The preference for a specific handedness of biological molecules has long intrigued scientists. The question of how chiral symmetry was broken and subsequently biased towards left-handed molecules is central to the understanding of the origin of life on this planet. As a step towards understanding such processes, the assembly of individual molecules on surfaces can be studied with modern surface science techniques. Low-temperature, ultra-high vacuum, scanning tunneling microscopy (LT-UHV STM) will be used to capture exact molecular arrangements, which will then be coupled with liquid and electrochemical STM (EC-STM) to replicate biological conditions for model systems such as amino acids on metals. In addition to imaging molecular self-assembly with nanoscale resolution, STM images will be used to understand chiral propagation and recognition, which is directly applicable to origin of life studies. Beyond the transfer of chirality, these biological systems are relevant for the study of the preference for secondary structures by different amino acid residues. In order to study these systems, several research objectives are proposed: (1) Establish a baseline for molecular assembly and how molecular adsorption alters the underlying metal substrate in UHV. (2) Use ambient, liquid, and EC-STM to determine if the observed UHV behavior can be extended to more realistic conditions. (3) Investigate how the chirality of L-amino acids is transmitted across a 2D surface in UHV. This proposal addresses the critical need to ascertain a connection between model chiral surface studies and studies performed with similar resolution under relevant biochemical conditions.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
