Nitrogen-doped graphic carbon protected Cu/Co/CoO nanoparticles for ultrasensitive and stable non-enzymatic determination of glucose and fructose in wine

Food safety has always been a very serious and global concern. Content determination of each component is one of the most routine analyses in food testing. Here, nitrogen-doped graphic carbon (NGC)-coated Cu/Co/CoO nanoparticles (Cu/Co/CoO/NGC) show excellent performance for glucose and fructose detection in wine. The high sensitivity (1,035 μA mM⁻¹ cm⁻²), low determination (0.2 μM) and large linear range (10-9,300 μM) characteristic of the Cu/Co/CoO/NGC sensor are attributed to the synergistic effect between the Cu, Co and CoO nanoparticles coated by NGC and the catalytically active M-Nx moieties (M = Cu and Co). Importantly, the good stability and antioxidation of the Cu/Co/CoO/NGC electrode result from the protection provided by the NGC shell. In addition, disposable, low-cost, and compact screen-printed carbon electrodes (SPCEs) modified by the Cu/Co/CoO/NGC (Cu/Co/CoO/NGC/SPCEs) were used to detect the sugar content in wine samples with a good reliability (R.S.D. = 1.7%) and recovery (103.2%). Thus, Cu/Co/CoO/NGC/SPCEs will be popular in the detection of real samples.