Photoelectrochemical and Non-Enzymatic Glucose Sensor Based on Modified Fehling's Test by Using Ti/TiO2 NTs-rGO-Cu2O Electrode

Herein, semiconductor Cu2O/reduced graphene oxide (rGO) coated TiO2 nanotubes (NTs) arrayed titanium foil was used as a photoelectrochemical (PEC) glucose sensor. The concentration of Cu2O nanoparticles (NPs) obtained by Fehling's solution is directly proportional to glucose amount, and the sensor combined the sensitive feature of PEC analysis and low-cost production of enzymeless sensors with the modified Fehling's test for the first time. The greatly enhanced photocurrent can be attributed to the p-n heterojunction formation between Cu2O NPs and TiO2 NTs, combined with the excellent conductive rGO, which can simultaneously enhance the charge separation efficiency and facilitate electron transfer. Also, rGO caused Cu2O NPs to cohere with each other on the electrode surface. The wide linear measurement range was found to be 0.0007-20 mM, with a sensitivity of 0.87 mu AmM-1 at 0 V vs Ag/AgCl. The proposed nanocomposite can be used for the glucose measurements in beverages. (C) 2019 The Electrochemical Society.