The development of advanced electrode materials based on hollow metal hydroxide nanosheets/carbonaceous nanostructures that have unique chemical/physical properties and sizeable inherent cavity to load specific chemical, has attracted immense attention. Herein, novel metal hydroxide nanosheets/carbonaceous nanostructures based on hollow mesoporous Ni(OH)2 nanosheet double shelled on hollow nitrogen doped carbon nanotubes (Ni(OH)2@Nsingle bondC n-Tube) were designed. The Nsingle bondC n-Tube skeleton was derived from its corresponded Fe2O3 nanorod with a simple self-polymerizing method, followed by an annealing and etching method. This advanced core-double shell array with ordered hierarchical Ni(OH)2 nano-architectures was successfully used as a high performance surface substrate for cortisol (COR) aptasensing. The Ni(OH)2@Nsingle bondC n-Tube shows unique characteristics including high surface area with rich functional group for bonding and fixing aptamer when used as a surface substrate. This proposed aptasensor can detect COR in a linear concentration between 1 pM to 80 pM and 0.1 nM to 25 nM with a detection limit of 0.3 pM and good selectivity in the presence of various interferences.
