▎ 摘　　要

Till now, the reported electrochemical sensors for metronidazole detection generally limited to the micromole per liter level, the trace detection in the low concentration range (nanomole per liter level) cannot be realized, which cannot meet the need for metronidazole determination at low concentrations in real clinical samples. In this work, a simple one-pot hydrothermal reduction method was applied to synthesize flower-like cobalt anchored on reduced graphene oxide (f-Co@rGO) nanocomposite. The prepared f-Co@rGO/GCE electrochemical sensor realize ultrasensitive quantitative determination of metronidazole in nanomole per liter level, obtained a wide linear detection range of 0.025-500 nM and a low detection limit of 0.015 nM (S/N = 3), far better than previous works. Moreover, the prepared sensor was successfully used for accurate determination of metroni-dazole in real serum samples, got a satisfied result. The f-Co@rGO/GCE electrochemical sensor has wide application prospects in clinical monitoring and drug quality control of metronidazole.