Nanofiber-shaped Co3O4@In2O3 composite for high-performance enzymeless glucose sensing

Abstract

Cobalt tetraoxide (Co3O4) holds great potential for enzymeless glucose detection due to its strong redox capabilities. However, its poor electrical conductivity limits the charge transfer and hence weakens its catalytic activity when utilized as the electrode of electrochemical sensors, such as enzymeless glucose sensor. In this study, we developed an indium oxide (In2O3)-wrapped Co3O4 nanofibers (Co3O4@In2O3 NFs) based electrochemical sensor for the enzymeless glucose detection, with an ultra-low limit of detection (LoD) of 8.85 nM (S/N = 3), a wide detection ranging from 10 nM to 118 μM, and a high sensitivity of 1197.5 μA mM-1cm-2. In addition, this sensor exhibits good selectivity, reproducibility, and long-term stability for over 30 days. The sensing performance of bare Co3O4 NFs towards glucose has been significantly enhanced by incorporating in high conductive In2O3, which is mainly attributed to the synergistic combination of the electrocatalytic activity of Co3O4 NFs, as the delicately designed core, and the excellent conductivity of In2O3, as the shell. Thus, this novel Co3O4@In2O3 NFs composites modified electrochemical has a huge potential to be further developed for the enzymeless glucose analysis in practical clinical settings.