Application of nanoporous gold in planar and mesh forms in electrochemical superoxide biosensing

We employed the large surface-to-volume ratio of nanoporous gold (NPG) to build a set of highly sensitive superoxide electrochemical biosensors. Once functionalized with cytochrome-c (cyt-c) the NPG-based electrodes displayed a superoxide sensitivity of 0.24 nA nM −1 and a low-level of detection of 5 nM towards superoxide. The planar electrodes were then interfaced with HUVEC cells and were able to detect the release of extracellular superoxide upon stimulation with an endogenous superoxide producer. In addition, we studied the superoxide sensing performance of a three-dimensional (3D) macroporous mesh of gold decorated with NPG as a potential ultrasensitive superoxide biosensor.