Efficient DNA-assisted synthesis of trans-membrane gold nanowires

Abstract

1Whereas electric circuits and surface-based (bio)chemical sensors are mostly constructed in-plane due to ease of manufacturing, 3D microscale and nanoscale structures allow denser integration of electronic components and improved mass transport of the analyte to (bio)chemical sensor surfaces. This work reports the first out-of-plane metallic nanowire formation based on stretching of DNA through a porous membrane. We use rolling circle amplification (RCA) to generate long single-stranded DNA concatemers with one end anchored to the surface. The DNA strands are stretched through the pores in the membrane during liquid removal by forced convection. Because the liquid-air interface movement across the membrane occurs in every pore, DNA stretching across the membrane is highly efficient. The stretched DNA molecules are transformed into trans-membrane gold nanowires through gold nanoparticle hybridization and gold enhancement chemistry. A 50 fM oligonucleotide concentration, a value two orders of magnitude lower than previously reported for flat surface-based nanowire formation, was sufficient for nanowire formation. We observed nanowires in up to 2.7% of the membrane pores, leading to an across-membrane electrical conductivity reduction from open circuit to o 20 Ω. The simple electrical read-out offers a high signal-to-noise ratio and can also be extended for use as a biosensor due to the high specificity and scope for multiplexing offered by RCA.

Review of the Electrical Characterization of Metallic Nanowires on DNA Templates

“…Subsequent amplification of the metals lead to metallic nanowires, which were electrically characterized by contacting both sides of the membrane. The resistance depended on the amplification time of the nanoparticles and dropped to 10 for times longer than 45 min [ 21 ].…”

“…Electrical characterization of nanowires has been performed by either contacting them directly with electrodes [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] or using scanning probe microscopy [ 25 , 26 , 27 , 28 ]. In most measurements, contact resistances dominated over the contribution from the resistance along the wire, and careful studies of the conductance of the wires indicated that the resistivity is higher than purely metallic resistivity.…”

Fabrication and temperature-dependent electrical characterization of a C-shape nanowire patterned by a DNA origami

“…Nanoparticles can be attached at specific sites by functionalizing DNA single strands at the desired location of the origami structures either chemically or by extending staple strands with additional nucleotides that serve as sticky ends for complementary sequences. Fully metallic gold wires can be produced this way by metallizing an array of gold NPs [19][20][21][22][23] .The degree of miniaturization achievable through DNA origami guided assembly of gold nanowires, however, is still to be determined. Here we explore the feasibility of the DNA origami technique for creating nanodevices within the current size limits by fabricating a split-ring resonator (SRR), a tiny LC circuit 24 .…”

“…Nanoparticles can be attached at specific sites by functionalizing DNA single strands at the desired location of the origami structures either chemically or by extending staple strands with additional nucleotides that serve as sticky ends for complementary sequences. Fully metallic gold wires can be produced this way by metallizing an array of gold NPs [19][20][21][22][23] .…”

Introductory Chapter: DNA as Nanowires

“…Further macrocycles, DNA quadrilateral, DNA knots, Holliday junctions, and other periodic crystal structures were also designed. DNA-mediated self-assembly of nanostructures has been extended to metallic nanowires [14][15][16]. In a study, DNA as a template was used to grow conducting silver nanowires [14].…”