Graphene on Nanoscale-Thick Au Films: Implications for Anticorrosion in Smart Wearable Electronics

Gold is normally considered inert to chemical reaction. Nevertheless, as a common electrode material, it would suffer from corrosion when exposed to certain solutions such as sweat and body fluids. Here, we report low-temperature plasma-enhanced chemical vapor deposition (PECVD) of graphene on gold and demonstrate its feasibility for anticorrosion application. The effects of hydrogen-to-methane ratio and the underlying gold substrate on the graphene growth are investigated, and the growth mechanism of PECVD graphene on gold is proposed. When immersed in an oxygenated saline solution, the PECVD-grown graphene-covered gold surface is found to remain intact after an acceleration soaking test at 90 °C for 24 h, which is in contrast to the degradation of bare gold surface subject to the same test. Our findings suggest that consumer/medical wearables and implantable devices with exposed gold can benefit from the protection of a direct, low-temperature PECVD-grown graphene layer for anticorrosion, thereby prolonging the efficacy and reliability of gold electrode-based biosensors.