Facile electrodeposition of environment-friendly Cu2O/ZnO heterojunction for robust photoelectrochemical biosensing

A novel environment-friendly all oxide semiconductor Cu2O/ZnO heterojunction was first applied in photoelectrochemical biosensing. The heterojunction was prepared by facile two-steps of electrodeposition and characterized by scanning electron microscopy, X-ray diffractometry, and ultraviolet and visible spectrophotometer. The enhancement of photocurrent is attributed to the rapid and efficient electron transition and the inhibition of photo-induced electron–hole pairs recombination, which stems from the formation of energy level matching Cu2O/ZnO heterojunction. Using glutathione (GSH) as a model, the fabricated photoelectrochemical sensor showed good performances with a rapid response, facile preparation, wide concentration range, excellent stability and low detection limit (0.8 μmol L−1). It had been successfully applied to the detection of GSH in glucose injection and the result agreed well with that given in the instruction. This strategy opened a new channel for Cu2O/ZnO heterojunction in photoelectrochemical sensing.