Anisotropic Plasmonic Copper/Copper Oxide Nanostructures by DC Electrophoretic Dissolution of Copper in Water for Plasmonic Sensing of Glucose

Plasmonic nanostructures (NS) are projected to solve many challenges associated with human health, energy conversion & storage and environment pollution. Here, we report a simple, facile and sustainable electrochemical approach that can be used for large-scale synthesis of anisotropic plasmonic copper/copper oxide NS with varying shapes and morphologies. Notably, the proposed method allow the synthesis of different shapes of copper/copper oxide NS viz. spherical, stars, rods, elongated hexagons and dendrite-like simply by controlling the associated parameters such as concentration of tri-sodium citrate (TSC) as an additive, solution pH and the applied voltage. Our results demonstrate that in addition to its stabilizing effect, TSC plays an important role in anodic dissolution of Cu rod and directing the shape of the NS. The proposed synthetic method is expected to prove very helpful to overcome the challenging task of large scale production of various shaped plasmonic NS in rudimentary, economical and sustainable manner. Moreover, the obtained plasmonic Cu NS shows excellent plasmonic sensing activity toward enzyme-less detection of glucose. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 0.16 nM and 0.54 nM, respectively.