Controllable synthesis of Pt nanoparticles on graphene oxide nanosheets and its application for electrochemical determination of dopamine

Establishing effective strategies to improve the performance of catalyst is a major area of interest within the field of electrochemical detection. In this paper, the nanocomposites of Pt catalyst with different morphologies decorated GO surface were successfully synthesized. The feature and diversity of Pt nanoparticles were confirmed by transmission electron microscope. The electrocatalytic performance and electroactive area of various modified electrodes were examined by cyclic voltammetry. According to Randles-Sevick equation, the active area of electrode modified with the shape of concave cube Pt nanoparticles is the largest. Moreover, compared with the other common stable planes, the concave cube Pt nanoparticles bound by high-index facets have the strongest current response. Furthermore, dopamine can be detected by amperometry at a typical working potential of 0.2 V (versus SCE) with a detection limit of 0.74 mu M (at the signal-to-noise ratio of 3), over two wide linear ranges (3 mu M-0.7 mM and 0.7 mM-4 mM). The sensing electrode also exhibited good reproducibility, stability and selectivity for dopamine determination.