▎ 摘　　要

Microcystin detection is of great significance and an urgent need because of its damage to water environments and human health. In this paper, an electrochemical aptasensor was developed by combining a 3D cobalt-based oxide modified boron and nitrogen co-doped graphene hydrogel (3D BNG/Co) with a DNA aptamer for sensitive detection of microcystin (MC-LR) through differential pulse voltammetry (DPV) technology. By using 3D BNG/Co as a catalyst and [Fe(CN)(6)](3-/4-) as a redox probe, the catalytic current signal was 3.8 times higher than that of the bare glassy carbon electrode, which can better monitor the electron conduction on the electrode surface and then improve the sensitivity. The as-fabricated electrochemical aptasensor displayed a wide detection range (0.1-1000 pmol L-1), low detection limit (0.03 pmol L-1), good sensitivity, and repeatability, which has potential applications for the protection of the ecological environment and human health.