Fig. 1.

Evaluation of the candidate redox mediators. (A) CV responses obtained using GCE electrodes in 0.1 M PBS (pH 7.4) containing 2 mM different mediators. Inset: CV response of 2AP. (B) CV responses obtained using MWCNTs-PEI-AuNPs modified- or bare GCE electrodes in 0.1 M PBS (pH 7.4) containing 2 mM HQ or APAP. (C) Chronocoulometric curves obtained using GCE electrodes at 0.0 V in 0.1 M PBS (pH 7.4) containing 2 mM APAP, PBS containing 2 mM APAP and 3 mM H₂O₂, PBS containing 2 mM APAP and 40 µg mL^-1 HRP, and PBS containing 2 mM APAP, 3 mM H₂O₂, and 40 µg mL^-1 HRP. (D) Charge values at 100 s from chronocoulograms using GCE electrodes in 0.1 M PBS (pH 7.4) containing 2 mM mediators and 3 mM H₂O₂, and PBS containing 2 mM mediators, 3 mM H₂O₂, and 40 µg mL^-1 HRP