Fischler Monika, Simon Ulrich, Nir Hadar, Eichen Yoav, Burley Glenn A, Gierlich Johannes, Gramlich Philipp M E, Carell Thomas
Institut für Anorganische Chemie, RWTH Aachen, Landoltweg 1, 52074 Aachen, Germany.
Small. 2007 Jun;3(6):1049-55. doi: 10.1002/smll.200600534.
Uniform bimetallic nanowires, tunable in size, have been grown on artificial DNA templates via a two-step metallization process. Alkyne-modified cytosines were incorporated into 900-base-pair polymerase-chain-reaction fragments. The alkyne modifications serve as addressable metal-binding sites after conversion to a sugar triazole derivative via click chemistry. Reaction of the Tollens reagent with these sugar-coated DNA duplexes generates Ag0 metallization centers around the sugar modification sites of the DNA. After a subsequent enhancement step using gold, nanowires < or = 10 nm in diameter with a homogeneous surface profile were obtained. Furthermore, the advantage of this two-step procedure lies in the high selectivity of the process, due to the exact spatial control of modified DNA base incorporation and hence the confinement of metallization centers at addressable sites. Besides experiments on a membrane as a proof for the selectivity of the method, atomic force microscopy (AFM) studies of the wires produced on Si-SiO2 surfaces are discussed. Furthermore, we demonstrate time-dependent metallization experiments, monitored by AFM.
