Electrically induced bonding of DNA to gold.
The development of single-molecule techniques has afforded many new methods for the observation and assembly of supramolecular structures and biomolecular networks. We previously reported a method, known as the single-molecule cut-and-paste approach, to pick up and deposit individual DNA strands on a surface. This, however, required pre-functionalization of the surface with DNA strands complementary to those that were to be picked up and then deposited. Here we show that single molecules of double-stranded DNA, bound to the tip of an atomic force microscope, can be deposited on a bare gold electrode using an electrical trigger (surface potential cycling). The interactions between the DNA and the electrode were investigated and we found that double-stranded DNA chemisorbs to the gold electrode exclusively at its end through primary amine groups. We corroborated this finding in experiments in which only a single adenosine nucleotide on a polyethylene glycol spacer was 'electrosorbed' to the gold electrode.
Erdmann
Matthias
M
Center for NanoScience, Ludwigs-Maximilians-Universität Munich, Amalienstrasse 54, 80799 Munich, Germany.
David
Ralf
R
Fornof
Ann R
AR
Gaub
Hermann E
HE
D004247:DNA / Q000737:chemistry*; D053672:Electrochemotherapy; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D009693:Nucleic Acid Hybridization / Q000379:methods
D006046:Gold; D004247:DNA