Chemiluminescence (CL) is defined as the production of light through a chemical reaction that is accompanied by energy release of >45 kcal mol−1. This phenomenon has been exploited as a powerful and important analysis tool in analytical chemistry. CL-based analytical methods present various advantages such as high sensitivity, rapidity, safety and controllable emission rate [1]. Recently, graphene oxide (GO) has attracted considerable attention of scientists due to its unique structure and extraordinary properties, and hold great promise for potential applications in nanomaterial and nanotechnology scientific fields. For instance, GO has been employed to increase the intensity of some of the CL reactions. In this work, GO was synthesized by using improved Hummer method. At this method used H2SO4 to intercalate graphite with the assistance of NaNO3, and KMnO4 to oxidize the acid-intercalated graphite. Hummer`s method has several merits. First, the use of a strong oxidant, KMnO4, ensures the completion of reaction within several hours. Second, no explosive ClO2 - is formed since the absence of chlorate. Third, the replacement of fuming HNO3 with NaNO3 eliminates the acid fog. The synthesized GO were characterized by exploiting FT-IR spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). In the following, it was found that GO layers were able to increase the intensity of weak CL reaction of hydrazine - sodium carbonate. Furthermore, the study of effect of some metal cations on the GO- hydrazine hydrate - sodium carbonate CL system revealed that cobalt (II) ions can catalyzed the GO - hydrazine hydrate - sodium carbonate CL reaction. After optimization of the concentration of the compounds involved in the CL system to achieve highest light emission, the CL system was used to measure cobalt (II) ions concentration. The developed CL method for cobalt (II) ions possessed the dynamic linear range from 6×10-7 to 1×10-5 mol/L and its detection limit
