▎ 摘　　要

In this work, Pd-decorated N-doped reduced graphene oxide (Pd/N-RGO) was successfully synthesized by a simple wet-chemical method without using any capping agent and stabilizer. The synthesized Pd/N-RGO composite has been carefully characterized by various techniques. The X-ray photoelectron spectra provide the evidence of successful incorporation of N into the N-RGO sheets, while the presence of Pd nanoparticles with the sizes of 5-20 nm on the N-RGO sheets was confirmed by the transmission electron microscopy. By integrating the advantages of the large surface area of N-RGO sheets and good electron transfer efficiency of Pd nanoparticles, the Pd/N-RGO-based sensor shows an improved electrocatalytic activity toward the estradiol oxidation. Therefore, the Pd/N-RGO composite can be used as an effective sensing platform for the non-enzymatic detection of estradiol. It also demonstrates that the fabricated sensor has two linear concentration ranges (0.1-2 and 2-400 mu M) and a low detection limit (1.8 nM) for the estradiol detection. Finally, the resulting sensor was successfully used to detect estradiol in some real samples and the satisfactory recoveries of 96.0-103.9% were obtained. The prepared Pd/N-RGO composite with more distinct merits including simple manufacture, preferable reproducibility and long-term stability can be a promising candidate for the advanced electrode material in sensing applications. (C) 2018 Elsevier B.V. All rights reserved.