Catecholate siderophore complexation on metal oxide surfaces

CHED 279

Whitney L Schmidt, schmidtw1@nku.edu and Heather A. Bullen, bullenh1@nku.edu. Department of Chemistry, Northern Kentucky University, Nunn Dr, SC 204 (C/O Heather Bullen), Highland Heights, KY 41099
Biofilm formation is problematic in industrial and medical settings. The objective in this work is to evaluate the impact of siderophores (iron sequestering molecules produced by many bacteria) in the initial attachment to metal oxide surfaces. It is known that siderophores have a strong affinity for iron, but their interaction with other metal oxides is relatively unknown. We present here work characterizing the complexation of model siderophores to metal oxide surfaces. The interaction of catecholate derivatives: catechol, 4-nitrocatechol, and 2,3-dihydroxynaphthalene with metal oxide sol-gels: TiO2, MnO2, Fe2O3, and Cr2O3 as function of ionic strength and pH were monitored. Macroscopic adsorption using high performance liquid chromatography (HPLC) and dissolution measurements utilizing atomic absorbance spectroscopy, graphite furnace (GTA), were conducted, and provide an indication of inner sphere vs. outer sphere complexation. The influence of Cr2O3 composition on adsorbate/surface interactions will also be presented.