Stability Enhancement of Laser-Scribed Reduced Graphene Oxide Electrodes Functionalized by Iron Oxide/Reduced Graphene Oxide Nanocomposites for Nitrite Sensors

An iron oxide/reduced graphene oxide (ION-RGO) nanocomposite has been fabricated to functionalize a low-cost electrochemical nitrite sensor realized by light-scribed reduced (LRGO) electrodes on PET substrate. To enhance the stability and adhesion of electrode, substrate was modified RF oxygen plasma, thin layer cationic poly (diallyl dimethyl ammonium chloride) deposited. Raman spectroscopy scanning electron microscopy coupled energy-dispersive X-ray (SEM-EDX) reveal that light-scribing process successfully reduces while forming porous multilayered structure. As confirmed cyclic voltammetry, LRGO response ferri-ferrocyanide is significantly improved after functionalization with ION-RGO film. Under optimized differential pulse voltammetry conditions, LRGO/ION-RGO electrode responds linearly (R2 = 0.97) in range 10–400 µM, achieving limit detection 7.2 μM sensitivity 0.14 µA/µM. A single stands for 11 consecutive runs. The novel fabrication leads highly stable reproducible sensors thus offers option rapid sensitive nitrite.