Growth of Ordered Metal Cluster Arrays on Regular Bacterial Surface Layers

M. Mertig, R. Wahl, and W. Pompe

Institut für Werkstoffwissenschaft, Technische Universität Dresden, D-01062 Dresden, Germany


The formation of highly ordered cluster arrays by chemical deposition of palladium and platinum onto a regular 2D protein template is studied. The crystalline bacterial surface layers of Sporosarcina ureae and Bacillus sphaericus, both exhibiting a p4 symmetry with a lattice spacing of ca. 13 nm, are used as the protein template. Cluster deposition onto the S-layer is achieved by chemical reduction of Pt and Pd salts. The growth kinetics of the clusters has been examined by UV-VIS spectrometry. Transmission electron microscopy reveals the formation of well separated metal clusters with an average diameter ca. 2 nm. The lateral cluster arrangement is defined by the underlying protein crystal. They are preferentially located in the nano-sized pores and gaps of the crystalline bacterial surface layers. We observe cluster densities up to 4×1012 cm-2.