2025/02/28 by Ma, Qifei, Chinappi, Mauro, Douaki, Ali +10
#Applied Physics (physics.app-ph) #Atomic and Molecular Clusters (physics.atm-clus) #FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.2502.20913
Recent research on silver nanowires prepared on DNA templates has focused on two fundamental applications: nano-scale circuits and sensors. Despite its broad potential, the formation kinetics of DNA-templated silver nanowires remains unclear. Here, we present an experimental demonstration of the formation of silver nanowires with a diameter of 2.2+0.4 nm at the single-molecule level through chemical reduction. We conducted equilibrium and perturbation kinetic experiments to measure force spectroscopy during the formation of Ag+ -DNA complexes and Ag-DNA complexes, using optical tweezers combined with microfluidics. The addition of AgNO3 resulted in an increase in force of 5.5-7.5 pN within 2 minutes, indicating that Ag+ compacts the DNA structure. In contrast, the addition of hydroquinone caused the force to decrease by 4-5 pN. Morphological characterization confirmed the presence of a dense structure formed by silver atoms bridging the DNA strands, and revealed conformational differences before and after metallization. We compare our experimental data with Brownian dynamics simulations using a coarse-grained double-stranded DNA (dsDNA) model that provides insights on the dependency of the force on the persistence length.