Nickel cobaltite micro-nano structures@PEDOT/graphene hybrid: A synthetical strategy constructed high performance biosensing interface

Nickel cobaltite (NiCo2O4) is a promising sensing material for H2O2. However, the poor electronic conductivity and agglomeration of NiCo2O4 in aqueous medium easily lead to poor sensitivity and selectivity, which are still two formidable challenges. Herein, the poly (3, 4-ethylene dioxythiophene)-coated NiCo2O4 rod-like micro-nano structures/reduced graphene oxide (NiCo2O4 RMNs@PEDOT2/RGO) hybrid is synthesized. The one-dimension hierarchical NiCo2O4 RMNs serve as a catalyst, while the RGO acting as support and charge collector. Particularly, the PEDOT is employed as a conductive wrapped layer and caking agent reduced interface resistance and quicken transport electrons from NiCo2O4 to the surface of RGO. Benefitting from the above synergistic effect of three components, the hybrid demonstrates high sensitivity (0.679 mA mM-1 cm-2), the low detection limit (it is estimated to be 0.031 µM), and a wide linear detection ranges of 0.388 µM–140.068 mM for H2O2 detection, which observably outperforms detection performances of previously reported other composites. The influence of morphology and interface structure of the hybrid towards performances is detailed. Besides, the practicality detection of H2O2 in merchant hydrogen peroxide disinfectant has been realized. The work provided a new strategy for improving the bio-sensing performance and accelerating the practical application of Co3O4. Keywords: Nickel cobaltite, H2O2 biosensor, Micro-nano composite, Reduced graphene oxide