Simultaneous electrical and plasmonic monitoring of potential induced ion adsorption on metal nanowire arrays

Abstract

Simultaneous LSPR and electronic sensing of potential induced ion adsorption onto gold nanowire arrays is presented. The formation of a Stern layer upon applying an electrochemical potential generated a complex optical response. Simulation of a lossy atomic layer on the nanowire array using the Multiple Multipole Program (MMP) corresponded very well to the experimentally observed peak position, intensity, and radius of curvature changes. Additionally, a significant voltage-dependent change in the resistance of the gold nanowire array was observed during the controlled formation of the electrical double layer. The results demonstrated that an applied electrochemical potential induces measurable changes in the optical and electrical properties of the gold nanowire surface. This is the first demonstration of combined plasmonic and nanowire resistance-based sensing of a surface process in the literature.

Nanowire formation is preceded by nanotube growth in templated electrodeposition of cobalt hybrid nanostructures

“…We have dubbed these Fluted Nanowires (FNW). The deposition of nanowires and nanotubes consisting of iron group elements and alloys has been previously observed, [2][3][4]10,11,[13][14][15][16] with previous studies noting a critical voltage threshold dividing deposition into two separate dominant growth regimes: nanowire at low overpotentials and nanotube at high overpotentials, 23 but to our knowledge there is no literature on the mechanisms that produce FNWs.…”

Single-Particle Plasmon Voltammetry (spPV) for Detecting Anion Adsorption

“…1, 2 Single nanometer-scale electrodes represent the sensor miniaturization limit, but pose the challenge of measuring extremely small electrochemical currents. [3][4][5] The direct readout of current from a single nanoparticle has only been achieved using a scanning tunneling microscope tip. 6 For metal nanoelectrodes, the plasmon resonance has been shown to report on the primary and secondary effects of electrode reactions.…”

Hot Holes Assist Plasmonic Nanoelectrode Dissolution

“…In Figure , photooxidative dissolution of single gold nanorods in a sodium chloride electrolyte is demonstrated. When anodic potentials are applied, soluble gold chloride complexes are formed, − and as they diffuse into the electrolyte, the nanorod volume is decreased. The nonequilibrium dissolution of individual nanorods is quantified through changes in the localized surface plasmon resonance, which depends on nanorod size and shape. , Because of the importance of high time resolution for monitoring nonequilibrium electrochemical processes, we use our recently developed “snapshot hyperspectral imaging” method (Figure a,b) to track heterogeneous size and shape changes during photooxidative dissolution in real time. ,,,, …”