DNA‐Programmable AgAuS‐Primed Conductive Nanowelding Wires‐Up Wet Colloids

Abstract

Self‐assembly of nanomaterials, directed by molecular or supramolecular interactions, is a powerful strategy to build nanoscale devices. Despite many advantages of such solution‐based processes, a big challenge is to realize interparticle ohmic contacts toward facilitated charge transport over a long distance. We report a new concept of primed nanowelding to thread solution‐borne nanoparticles in prescribed assemblies. The process starts with a gap‐specific deposition of Ag2E (E=S, Se) materials in pre‐assembled gold structures, which spontaneously transform into AgAuE semiconductors via directional gold diffusion. Treatment with tributylphosphine generates alloyed Au/Ag welding spots that conductively wire‐up nanoparticles into discrete “molecules” and micron‐long “polymers”. This method is compatible with DNA programming and delivers a possible way to solve the problem of the carrier‐transport dilemma in solution‐processed nanostructures for better‐functioning nanodevices.

Assembly and Healing: Capacitive and Conductive Plasmonic Interfacing via a Unified and Clean Wet Chemistry Route

“…Increasing the H 2 O 2 concentration caused a blue-shift of the emerged LSPR peaks, accompanied by increased peak intensities (Figure A). These phenomena coincided well with a charge transfer plasmon (CTP) for conductively welded AuNP dimers. − ,− Both a prolonged reaction period and an increased temperature promoted spectral evolution (Figure S20). In the case of relatively large 46 nm AuNP dimers, the CTP wavelength could reach above 900 nm by altering H 2 O 2 concentration (Figure Aiii, iii’) and reaction time/temperature (Figure S20).…”

“…In particular, the CTP position is closely related to the junction width and NP size. Thinner junctions or larger AuNPs give rise to more red-shifted CTPs, and vice versa. ,− As the original dimers were prepared by AIS, EDX mapping revealed the existence of silver on the final structures (Figure C), which could also be verified by a sulfurization reaction …”

“…10,65−67 As the original dimers were prepared by AIS, EDX mapping revealed the existence of silver on the final structures (Figure 4C), which could also be verified by a sulfurization reaction. 69 Two mutually nonexclusive mechanisms could exist for the H 2 O 2 -induced CTP reshaping. The migration of Au atoms into a dimeric gap could occur upon BSPP desorption.…”

Heterobimetallic Base Pair Programming in Designer 3D DNA Crystals

“…These two transition metal ions can selectively fill the gap between two pyrimidine nucleobases at the center N3 position of both nucleobases with a high ion specificity and orthogonality (Figure ). − While there have been many instances of metal-mediated DNA (mmDNA) base pair motifs solved through X-ray crystallography − ,, and NMR spectroscopy, , more data points are required to understand the behavior of these complexes in order to advance the use of metal base pairs for structured DNA nanodevices; and to our knowledge, no crystallographic examples yet exist showing both ions in the same base pair complex. ,, There have been a number of exceptions to the “silver binds cytosine and mercury binds thymine” paradigm, such as a non-B-form dT:Ag + :dT base pair, 4-thiothymine binding two silver­(I) ions at both the N3 and O4 positions, and more. ,− This suggests that under certain conditions, uracil family bases (dT, dU, and modified dU) have the ability to bind both silver­(I) and mercury­(II). In this regard, our current understanding regarding these metal-DNA interactions remains incomplete.…”

Steering DNA Condensation on Engineered Nanointerfaces

“…Second, the existence of a nanogap in the dimeric assembly provides a chance to initialize gDNA nucleation following a thermodynamic interface-cancelation rule. − The AuNP monomers and dimers were prepared following a previously developed Ag ion soldering (AIS) process (Figure S32). − Note that the AIS monomers/dimers were covered by thin layers of nonspecifically adsorbed Ag + and FSDNA . Symmetric and asymmetric depositions of gDNA were observed on the AIS monomers when Fe 2+ and Cu 2+ were involved, respectively (Figure a,c).…”