▎ 摘　　要

The authors demonstrate the exploitation of reduced graphene oxide (RGO) as a template for immobilizing zeolitic imidazolate framework-8 (ZIF-8) crystals loaded with the electrochemical probe Methylene Blue (MB). The framework was deposited on the surface of RGO in a one-pot process. Transmission electron microscopy, scanning electron microscopy and X-ray diffraction were employed to characterize the nanocomposite. The electrochemical behavior of rutin at a glassy carbon electrode (GCE) modified with the nanocomposite was investigated by cyclic voltammetry and differential pulse voltammetry. The modified GCE displays high electrocatalytic activity toward rutin oxidation at a relatively low working potential (0.4 V vs. Ag/AgCl). Under the optimal conditions, the sensor has an amperometric response that is linear in the 0.1 to 100 mu M rutin concentration range, with a 20 nM detection limit (at an S/N ratio of 3). The method was successfully applied to the determination of rutin in tablets and urine samples.