1. Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany (S.M.B., G.N., C.S., O.S.W.); and Institute of Analytical Chemistry and Radiochemistry, Graz University of Technology, Stremayrgasse 16, 8010 Graz, Austria (I.K.)