Amino acids, in the form of proteins, comprise the second-largest component of human muscles, cells, and other tissues. They also perform critical roles in neurotransmission and biosynthesis. Using a molecular imprinting technique, the goal of this project is to separate mixtures of amino acids and proteins present in certain brain tumors.
Using spin coating, a process that involves depositing a small puddle of fluid resin onto the center of a substrate and then spinning the substrate at high speed (typically around 4000rpm), we developed an imprinted polymer film using nylon 6 as the hosting polymer, allowing amino acids, the target molecules, to bind inside the polymer matrix with the presence of formic acid as the desired polymer-soluble solvent. Centripetal acceleration causes the resin to spread to the edge of the substrate leaving a thin film of resin on the surface, which we are then able to investigate.
Our goal is to study different template molecules added to the polymer matrix affecting surface morphology of these thin films and analyze the amount of amino acids that leach from the matrix as well as insert onto the memorable cavities created via solid phase extraction (SPE). We are able to investigate several which allows us to detect the chemical interaction between amino acids and the polymer chains. Depending on the functionality of the amino acid, the resin can be stiffer or softer, and the interactions can also alter the melting point of the polymer matrix.
For the second phase of the project, our focus is on the quantification of the amount of amino acid that is bound by the imprinted nylon films. Gas Chromatography (GC) is a robust analytical method that has been used extensively to quantify a variety of molecules. However, this technique is not suitable for amino acid quantification because of its stable solid phase property that cannot be sublimed to gas. In light of the challenges of using GC for amino acid quantification, we seek to employ an innovative quantification method called High Performance Liquid Chromatography (HPLC) with pre-column derivatization. With this technique, we are able to derivatize amino acids to form a compound that is easily detected by HPLC. The procedure is efficient, cost effective and highly precise.
The Dartmouth Graduate Alumni Research Award will allow us to utilize this powerful technique to investigate the amount of amino acids that is absorbed by the imprinted films we develop in our lab and will go a long way to help us establish a framework to understand the binding capacity of these amino acid-imprinted films.