Nanoporous CuO layer modified Cu electrode for high performance enzymatic and non-enzymatic glucose sensing

Nanoporous CuO layer on Cu foil with a thick Cu2O interlayer is synthesized via post annealing of previously fabricated Cu(OH)(2) nanowires at 500 degrees C under an oxygen flow. The formation of the thick sandwiched Cu2O layer is realized through the outward diffusion of Cu ions and subsequent oxidation. An O-2 pressure above the dissociation pressure of CuO is used to form a CuO layer at the outer surface of the structure, thus realizing a low cost structure having a porous and high isoelectric point layer. The Cu/Cu2O/CuO structure is used as an efficient electrode for glucose sensing. Sensitivities of 20.7 mA mM(-1) cm(-2) at 0.8 V versus Ag/AgCl and 1066 mu AmM-1 cm(-2) at 0.6 V versus Ag/AgCl are achieved in an enzymatic and non-enzymatic glucose sensing schemes, respectively. The improved electrochemical sensing ability might be attributed to the efficient electrocatalytic reaction on the high crystal quality CuO layer and the porous structure.