▎ 摘　　要

A novel method to detect Pb2+ in soybean sauces was proposed by modifying commercially provided multilayer graphene on a disposable screen-printed carbon electrode to achieve increased electrochemical performance. Raman spectroscopy presented the low fluorescence background of graphene and revealed that the defects of sp(2) graphite were improved by graphene. The evident difference between the reduction and oxidation peaks of K3Fe(CN)(6) was observed on the graphene modified screen-printed carbon electrode and could be compared with the electrochemical performance of a glass carbon electrode. To reuse the modified electrode, a new regeneration method was developed according to the largest stability constant of NaOH with Pb2+. The key experimental parameters related to the fabrication of the electrode and the voltammetric measurements were optimized based on stripping signals where peak currents increased linearly with the Pb2+ concentration within the range of 5.0x10(-7) and 5.0x10(-6) mol/L by the standard addition method. The concentration of the soybean sauce sample was calculated to be 1.6x10(-7) mol/L (0.032 mg/L) by extrapolation; by comparison, a concentration of 0.03576 mg/L was calculated through inductively coupled plasma mass spectrometry. Thus, the proposed electrode was demonstrated to be reliable and effective for detecting Pb2+ and could be further developed and combined with a palmtop electrochemical instrument to achieve in-situ detection.