Noble metal nanoparticles are directly and homogeneously grown onto graphene-oxide (GO) sheets in oleylamine. After the oleylamine is removed, the GO sheets are exfoliated by the nanoparticle pillars to further form hierarchical GO nanostructures with molecule accessible nanopores. With specific sensing-groups modified, the porous-layered nanostructure can be constructed onto resonant microcantilevers for chemical sensing.