Highly sensitive detection of glucose at a novel non-enzyme electrochemical sensing based on Mo-doped CoO Nanosheets

Graphical Mo−CoO nanosheets grown on nickel foam was used as a non-enzymatic glucose sensing electrode with a high sensitivity (89.3 mA cm −2 mM −1 ) and a low detection limit (0.43 μM). DFT calculations results confirmed that the lower adsorption free energy (−1.79 eV) for glucose adsorbing on Mo−CoO-1 surface promoted the glucose electrochemical oxidation reaction and then enhanced the sensing performance. In this work, a Mo doped CoO nanosheet grown on nickel foam (labeled as: Mo−CoO) with defect-rich and improved electron transfer capacity was designed to be used as a novel non-enzyme electrode material. Physical characterizations demonstrated the Mo elements were doped inside of the samples and they were mutually stabilized with each other, resulting in a high structural stability electrochemical catalytical activity even if the content of Mo was low. For non-enzymatic glucose electrochemical sensing, the prepared Mo−CoO-1 showed a remarkable sensitivity of 89.3 mA cm −2 mM −1 , and a low detection limit of 0.43 μM. Density functional theory (DFT) studies revealed that the doped Mo atom exhibited a higher d-band center compared to the Co atom. A stronger p-d orbital hybridization between the glucose and the Mo atoms indicated the enhancement of glucose adsorption and activation. Importantly, Mo−CoO-1 provided a good selectivity and long-term stability, which can be expected to be used in future practical applications.