1. Center for NanoBioEarth, Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg, Virginia 24061, Plants, Soils and Climate Department, Utah State University, 4820 Old Main Hill, Logan, Utah 84322, Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, and SIMBIOS Centre, Abertay University, Bell Street, Dundee DD1 1HG, U.K.