Engineering Co3O4 with Co defects for highly sensitive nonenzymatic detection of glucose

Defect engineering was considered as an effective strategy to regulate electrocatalytic activities of transition metal oxides . However, there are seldom reports about metal defects in electrochemical sensing. In this work, Co-defected Co 3 O 4 was synthesized via thermal treatment of glycerolatocobalt (CoGly) precursor for constructing a novel electrochemical nonenzymatic glucose sensor. The obtained nanomaterials were characterized by transmission electron microscopy (TEM), powder X-ray diffractometry (XRD), Raman spectra , X-ray photoelectron spectroscopy (XPS) and electrochemical techniques . The presence of Co defects regulated electronic structure of Co 3 O 4 , which not only speeds up electron transfer rate but also exposes more high-valent Co sites, thus improving electrocatalytic activities. Under optimized conditions, Co-defected Co 3 O 4 electrode exhibited excellent performance for glucose analysis with a wide linear range of 0.2 µM to 0.5 mM, a low detection limit of 0.16 µM. Importantly, an ultrahigh sensitivity of 2595.7 µA·mM −1 ·cm −2 was also obtained, which was about 10 times higher than that of conventional Co 3 O 4 . Therefore, engineering Co 3 O 4 with Co defects is an effective strategy to tailor electrocatalytic activity, which sheds light on the potential applications of metal defects in the field of electrochemical nonenzymatic sensing.