fig5

Figure 5. (A) Effect of applied potential on amperometric response of the sensor to 1 mM glucose in 0.5 M Na₂SO₄; (B) Amperometric response curves of the ACO electrode for different glucose concentrations in 0.5 M Na₂SO₄ under an applied potential of -0.4 V (vs. Ag/AgCl); (C) Calibration plot of current response vs. different glucose concentrations with fitted lines of 1-100 µM, 100 µM-1.6 mM, 1.6-10 mM (the inset image corresponds to the concentration ranges of 1 µm-10 mM); (D) Amperometric responses of the ACO electrode to successive dropwise additions of glucose and interfering species (AA, UA, Sucrose, and NaCl) at -0.4 V (vs. Ag/AgCl); (E) EIS results of ACO and GaO_x-Ga electrodes in 0.5 M Na₂SO₄. The inset shows the equivalent impedance circuit; (F) Amperometric response curves of flexible sensors with ACO electrode in bent states of 0°, 60°, and 90° to glucose in 0.5 M NaCl-PVA electrolyte under the applied potential of -0.7 V. AA: Ascorbic acid; ACO: annealed Cu-Oxide; EIS: electrochemical impedance spectroscopy; UA: uric acid.