A highly sensitive non-enzymatic glucose sensor based on Cu/Cu2O/CuO ternary composite hollow spheres prepared in a furnace aerosol reactor

A novel ternary composite, Cu/Cu2O/CuO hollow spheres (HSs), synthesized using an aerosol furnace reactor (FuAR) was investigated for the first time as a non-enzymatic electrochemical biosensor for glucose detection. The composite HSs were synthesized by aerosolizing a mixture of copper nitrate, citric acid, and ammonia through a FuAR. Interestingly, the addition of ammonia played a crucial role in the in-situ formation of hollow Cu/Cu2O/CuO ternary composites. The HSs modified electrode was employed for non-enzymatic glucose detection where it exhibited a detection limit of 0.39 μM and an outstanding sensitivity of 8726 μA cm−2 mM−1 which is superior to existing Cu/Cu2O HSs and CuO HSs modified electrodes. The high sensitivity was attributed to the synergy arising from the ternary composition’s interfacing with multiple Cu redox couples and high surface area. The Cu/Cu2O/CuO HSs modified electrode also showed excellent selectivity in detecting glucose in the presence of interfering species, including chloride salts of Na+, K+, Ca2+, and anions of ascorbic acid (AA), dopamine (DA), and uric acid (UA). This simple and scalable FuAR technique will attract interest and enable in designing other high-performance metal/metal oxide composites for commercial glucose sensing applications.