This paper proposed a simple, efficient and sensitive electrochemical sensor for dissolved oxygen (DO) detection based on a galvanic displacement synthesized reduced graphene oxide–silver nanoparticles (RGO/Ag) composite modified grassy carbon electrode (GCE). The synthesized RGO/Ag nanocomposite was characterized by UV–vis spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate the graphene oxide (GO) has been successfully reduced during the galvanic displacement process and the average size of Ag nanoparticle is 52 nm. The RGO/Ag nanocomposite-modified GCE showed a significant enhancement of DO detection compared with bare and RGO-modified GCEs. Moreover, the proposed DO sensor also exhibited an excellent repeatability, reproducibility and anti-interference ability
