Enzymatic mimetics have been fabricated by loading Fe3O4 Nanos or Pt nanocatalysts onto the conductive carbon supports of hydrophobic carbon nanotubes (CNTs) dispersed by amphiphilic graphene oxides (GO) serving as the nanocolloidal "surfactant".The so prepared GCNT supports were first employed for covalently loading cubic Fe3O4 Nanos resulting in GCNT-Fe3O4 nanocomposites.