▎ 摘　　要

Metal oxide nanoparticles are highly active structural components for developing catalysts on highly functionalized graphene sheets which provide superior electrocatalytic activity, high stability as well as cost-effectiveness in electrochemical sensing application. In this present study, 2, 6 diaminopyridine functionalized electrochemically reduced graphene oxide with molybdenum oxide ternary composites, (2, 6 DAP-ERGO/MoO3) for use as a potent electroactive catalyst for detection of dopamine (DA), has been developed for the first time using the hydrothermal method. The formation of metal-nitrogen (Me-N) bonds and the growth of the nanosized MoO3 sheets on 2, 6 DAP-ERGO exhibited an influential role in the electrocatalytic activity, resulting in a remarkable enhancement of both oxidation and reduction process of dopamine. The proposed 2, 6 DAP-ERGO/MoO3 nanocomposite had a broad electro active surface area which enhance the capacity for dopamine adsorption and ultimately cause a remarkable increment in the anodic peak current by about 30 times with respect to bare glassy carbon electrode(GCE), demonstrating the significant electrocatalytic activity towards dopamine with relatively better sensitivity (271.57 mu AmM(-1)cm(-2)), and a broad linear range of detection (0.1-900 mu M) and lower limit of detection (0.025 mu M) having S/N = 3. Interference of coexisting electro active biomolecules was also investigated. The diffusion coefficient for dopamine determination was estimated to be 2.2 x 10(-4) cm(2)s(-1). Finally, the applicability of our proposed 2, 6 DAP-ERGO/MoO3 catalyst was analyzed using human urine sample.