▎ 摘　　要

In this work, we have investigated the in situ growth of Ag nanochains (AgNCs) on carboxyl-functionalized graphene oxide based on enzymatic metalization for the first time. The merit of this method is that the AgNCs could be generated directly on carboxyl-functionalized graphene oxide in a natural, environmentally friendly and sustainable way with high productivity. Furthermore, the Pt nanoparticles were wrapped around the AgNCs (Pt@AgNCs) which manifested some superior functions, such as excellent electrical conductivity and well-defined electrochemical redox activity. With Pt@AgNCs as the electrochemical redox probe, we developed a label-free electrochemical aptasensor for highly sensitive detection of platelet-derived growth factor. A linear response was obtained over a wide range from 6 pM to 40 nM with a detection limit of 1.97 pM.