Mesoporous gold nanoparticles supported cobalt nanorods as a free-standing electrochemical sensor for sensitive hydrogen peroxide detection

The performance of an electrochemical sensor for detecting small biomolecules can be greatly upgraded by properly controlling the chemical nanostructure of electrocatalyst. In this study, we successfully prepared a unique hierarchical three-dimensional nanoarchitecture based on gold nanocrystals supported cobalt nanorods on foam substrate via a facile synthesis approach. The Au-Co NRs/3DNF hybrid has been effectively utilized as a novel binder-free self-supported electrochemical sensor for hydrogen peroxide detection with wide linear detection range of 2–799 μM, low limit of detection of 1.42 μM, long-term stability, and very excellent selectivity. Besides, the hybrid precisely detected hydrogen peroxide in real samples. The achieved results can be explained by the synergistic effect produced by the combination between gold and one-dimensional Co NRs. In addition, the 3D nanostructure with self-supported ability, large surface area, and without the use of any polymer binder, leads to the enhanced electroactive sites, conductivity, electrolyte penetration, and ion diffusion, thereby promoting the sensing performance. The results imply that the hybrid may open a prospective way for developing electrochemical sensor towards efficient detection of hydrogen peroxide.