INFEWS N/P/H2O (SusChEM): Understanding structure and organization of receptors at water interfaces for discovery of phosphate recognition design principles

Indiana University, Bloomington IN

Investigators

Abstract

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Amar Flood of the Department of Chemistry at Indiana University and Professor Heather Allen at the Ohio State University are developing an understanding of how to bind phosphate selectively in water. Phosphorous is a non-renewable resource and a critical nutrient for enhancing crop yields to help feed the growing population of the planet. However, a significant amount of the phosphorous that is added as phosphate to agricultural fields is lost as run-off into streams and rivers. The resulting buildup of phosphate in natural waterways helps fuel algal blooms that kill off all other aquatic life, can lead to toxins in the municipal water supplies and, when in the oceans, leads to toxic seafood. For these reasons it is important to develop new chemistries for recovering phosphate dissolved in water. This project also involves the education of undergraduate and graduate students through interdisciplinary research training, the development of "Grand Challenge" lectures on closing the human phosphorous cycle, and the design of a new general chemistry course series. Professors Flood and Allen aim to understand and discover the factors controlling the recognition of phosphate by making use of synthetic receptors organized in monolayers at water interfaces. These interfaces create potent environments with dielectric constants much below bulk water offering the potential to substantially enhance affinities, yet such interfaces are poorly understood. Such interfaces also serve as fundamental models for the sequestration materials needed to help close the human phosphorus cycle. This collaborative effort involves the synthesis of a series of receptors, the determination of the affinity and selectivity of phosphate binding to the receptors when they are organized at air-water interfaces, and spectroscopic studies to ascertain the geometries of the resulting phosphate-bound complexes.