Self-template formation of porous Co3O4 hollow nanoprisms for non-enzymatic glucose sensing in human serum.

Abstract

A novel type of porous Co3O4 hollow nanoprism (HNP) was successfully prepared using tetragonal cobalt acetate hydroxide [Co5(OH)2(OAc)8·2H2O] as precursor by a facile solvothermal process and a subsequent calcination treatment. The morphology and structure of the Co3O4 HNPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD) and N2 adsorption–desorption measurements. An enzyme-free glucose sensor was constructed based on the Co3O4 HNPs, and the electrochemical performance was tested by cyclic voltammetry (CV) and chronoamperometry. The as-prepared sensor exhibited a good electrocatalytic activity for glucose oxidation at the applied potential of 0.6 V in alkaline solution, with a high sensitivity of 19.83 μA mM−1 cm−2 and a high upper limit of 30 mM, which provide the potential for direct determination of blood glucose without any dilution pretreatment. The Co3O4 HNPs had a porous and tubular structure with a large amount of accessible active sites, which enhanced the mass diffusion and accelerated the electron transfer. Moreover, the sensor also demonstrated a desirable stability, selectivity and reproducibility, and could verify the non-enzymatic analysis of glucose in real samples.