In situ fabrication of Co(OH)2 by hydrothermal treating Co foil in MOH (M = H, Li, Na, K) for non-enzymatic glucose detection

Cobalt hydroxides, Co(OH)2, was in situ fabricated taking metal-cobalt as both conductive substrate and cobalt source by a facile hydrothermal method. It is found that the Co(OH)2 morphologies is highly depended on the solution including H2O, LiOH, NaOH and KOH. All the Co(OH)2 shows potential application for non-enzymatic glucose detection. Especially, nanosheets after hydrothermal treating Co foil in KOH shows linearly amperometric signals to glucose concentration up to 3 mM with a detection limit of 0.5 μM, fast response time (6.5 s–100 μM), and an excellent sensitivity of 1646 μA mM−1cm−2 (R2 = 0.9904). These findings provide a new opportunity to directly fabricate Co(OH)2 on Co foil for glucose detection, which does not only simplify the electrode fabrication procedure to enhance the electron transport, but also favor the full utilization of active nanocatalysts to improve the electrochemical performance.