▎ 摘　　要

A single step preparation of platinum nanoflowers and reduced graphene oxide nanocomposite (PtNFs/rGO) modified electrode was accomplished using cyclic voltammetry (CV). A flower-like platinum structure with the homogeneous distribution of PtNFs/rGO on the screen-printed carbon electrode surface was clearly observed by scanning electron microscopy (SEM). The electrochemical behaviors of PtNFs/rGO electrode were systematically investigated by CV. Comparing with an unmodified electrode, PtNFs/rGO electrode provided 5-fold increase in anodic peak current. This newly fabricated electrode not only accelerated the electron transfer between diclofenac and the electrode surface but also promoted the accumulation of diclofenac on electrode surface leading to enhanced electrochemical sensitivity for the quantitative analysis of diclofenac. By using differential pulse voltammetry (DPV), a calibration curve of diclofenac was linear in a range of 0.1-100 mu M, and a limit of detection was found to be 40 nM (S/N = 3). Eventually, this system was successfully applied for the determination of diclofenac in human urine samples.