Chemiluminescence (CL) reactions are chemical reactions in which the energy of reaction is released in the form of light. In recent decades, CL- based analytical methods have received extensive attention due to their advantages such as high sensitivity,wide liner range, simplicity and inexpensive equipment [1]. Graphene oxide (GO) is a material in the form of sheet with atom thickness that can disperse in water [2]. GO can intensify the light emission from the CL reaction of luminol - oxygen. This phenomenon is due to the ability of GO in production of reactive oxygen species [3]. Dobutamine prescribed for heart disease treatment and its measurement in the pharmaceutical industry is very important from the quality of manufactured drugs point of view. In this work, a new, simple and inexpensive method was developed to measure dobutamine. The method was based on inhibitory effect of dobutamine on the GOluminol- O2 CL reaction. GO was synthesized by improved Hummers method. The synthesized GO was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), ultra violet absorption (UV-Vis) and fourier transform infrared spectrometry (FTIR).. The effect of concentrations of GO, NaOH and luminol were on CL intensity was investigate and optimized. Under the optimum conditions, a liner relationship was obtained between CL intensity and concentration of dobutamine in the range of 3×10-7-5×10-6mol L-1. The detection limit of this method 2.4 × 10-7 mol L-1 and its relative standard deviation (RSD) for nine replicate determinations of 2 × 10-6 mol L-1 dobutamine was 1.2%
