▎ 摘　　要

A novel mercury-free electrochemical sensor for uranium has been fabricated with two-dimensional polydop-amine-reduced graphene oxide (PDA-rGO) composites, which is obtained through a simple self-polymerization of dopamine monomers on GO surface. Morphological characterization displayed that PDA was well coated on the rGO and the PDA-rGO composites exhibited a rougher structure. Furthermore, the introduction of PDA greatly increased the amount of functional groups, and PDA-rGO showed significantly enhanced detection activity for uranium. The influence of several experimental parameters such as pH of supporting electrolyte, accumulation time and PDA-rGO amount on the sensitivity of uranium measurement were studied. Under the best conditions, the PDA-rGO electrode could detect U(VI) concentration from 0.1 to 50 mu mol L-1 with a detection limit of 0.05 mu mol L-1. Besides, the developed sensor exhibited higher selectivity and stability, suggesting that the proposed uranium sensor has broad application prospects in the determination of trace uranium.