Highly sensitive non-enzymatic glucose sensing using gold nanocages as efficient electrode material

This study describes the application of gold nanocages (Au NCs) for the development of enzyme free electrochemical glucose sensor. The described sensor system is based on the direct modification of glassy carbon electrode (GCE) with Au NCs prepared using simple galvanic replacement reaction. The excellent sensitivity in this case was attributed to the high surface area (interior/exterior) and cavity confinement phenomena (cage effect) associated with Au NCs during the oxidation of glucose. The observed electro-catalytic cage confinement phenomena for Au NCs was elaborately studied using cyclic voltammetry (CV) against solid gold nanoparticles (Au NPs) modified electrode. In addition to this, the developed sensor system was found highly resistive towards interfering species such as uric acid (UA), ascorbic (AS), dopamine (DP) and monosaccharide like fructose (FC) and maltose (ML). The electro-catalytic affinity of Au NCs for the oxidation of glucose enabled development of highly sensitivity (2131 μA cm−2 mM−1) and selective sensor with lower detection limit estimated to be 0.1 mM and linear working range of 1.0-9.0 mM.