Photo-Assisted Barrier Effect for Improving the Sensing Performance to Copper Ions

Copper ions (Cu 2+ ) pollution poses a serious threat to Marine ecology and fisheries, but the online detection is difficult due to seawater interference. Herein, photo-assisted barrier effect is introduced into electrochemical detection as a driver to generate electrochemical response. The n–n junction barrier exhibits excellent adjusting effect on electrochemical response under photoexcitation and could effectively drive electrochemical response by Cu 2+ adsorption. The prepared Ti/TiO 2 /In 2 O 3 /Chitosan wire is used for direct Cu 2+ detection, and the trace detection with the low detection limit (59.08 n m ) is achieved. The strong interference of seawater is resisted effectively by using photo-assisted barrier effect, and the good recovery rate (94.9–107.1%) in the actual seawater detection make it promising for practical applications. It is a new approach to develop electrochemical sensors by using photo-assisted barrier effect to resist interference.