Presentations of Chemistry Research Results
Joseph Serafin, Department of Chemistry, St. John’s College of Liberal Arts and Sciences
Many biological processes such as protein folding are studied with the use of additional solution components (such as urea or sodium chloride) to drive the system to the desired state. A key question is how does the solvent affect this response in the system, and which components of the system are affected by the cosolvent. We have developed a novel approach to this problem by adapting existing methodologies to cosolvent modified aqueous solutions. We used force measurements in a chemical force microscope (CFM) to determine the interfacial free energy of a self-assembled monolayer exposed to the various aqueous solutions.
For the initial study, we chose aromatic molecules (surface bound phenyl groups) as our sample system, and the cosolvents used were all common to biochemistry. Several selections from the Hofmeister series were used as cosolvents, as well as urea and guanidinium chloride. Quantitative and qualitative differences are observed in the cosolvent systems studied on the aromatic surfaces.