Peptide Amphiphiles Designed to Capture and Release Phosphate

While there have been recent advances in designing soft materials to perform intriguing functions, there remains a dearth of materials that can molecularly recognize, capture, release, and collect targeted nutrients or contaminants to recycle on the nano-scale. Peptide amphiphile systems represent a promising, unexplored candidate for such materials with their sequence-specific synthetic control, tunable secondary structure, and self-assembled supramolecular architectures. Compared to other anion binding materials that have complex synthetic routes or are unstable in water, peptide amphiphiles utilize the well-established, monodisperse synthetic technique of FMOC solid phase peptide synthesis to produce materials that perform reliably and optimally in aqueous environments. In our work, we have incorporated a phosphate-binding amino acid motif into the headgroup of peptide amphiphiles, which is then systematically displayed to the environment in self-assembled wormlike micelles. These micelles then form a dense, entangled network to act as an absorbent material that can capture phosphate at designated pH values and then release it to be collected in a controlled and purified manner. This work will present the design, characterization, and phosphate-binding functionality of these specially designed peptide amphiphile materials.