Fig. 3. DPV curves of the modified electrode contained 5 mg ml⁻¹ Fc in PBS with SA (400 μM) plus IAA (125 μM, 200 μM, 300 μM, 400 μM, 600 μM, (a) to (e)) (A); IAA (400 μM) plus SA (125 μM, 200 μM, 300 μM, 400 μM, 600 μM, (a) to (e)) (B); IAA (400 μM), SA (400 μM) and Fc (1 mg ml⁻¹, 2.5 mg ml⁻¹, 5 mg ml⁻¹, 7.5 mg ml⁻¹, 10 mg ml⁻¹, (a) to (e)) (C).