A glassy carbon electrode modified with ordered nanoporous Co3O4 for non-enzymatic sensing of glucose

Ordered porous Co3O4 materials with pore sizes of 5 nm (Co3O4-5), 20 nm (Co3O4-20), and 70 nm (Co3O4-70) have been synthesized via a hard-template method and were studied as catalysts to bring insight into non-enzymatic electrochemical sensing of glucose. A glassy carbon electrode modified with Co3O4-70 responds more quickly and sensitively to glucose than those modified with Co3O4-5 or Co3O4-20. The sensor based on the use of Co3O4-70 and operated at a working voltage of 0.6 V (vs. Ag/AgCl) in 0.1 M NaOH solution shows a lower detection limit of 0.025 mu M, good repeatability and high selectivity over ascorbic acid, uric acid, dopamine, and KCl. These results suggest that ordered porous Co3O4 is a promising material for quantitative electrochemical determination of glucose, and that the pore size has a strong effect on performance.