Fig. 6. Differential pulse voltammetry (DPV) results at 20 μg mL⁻¹, 40 μg mL⁻¹ and 60 μg mL⁻¹ concentration of Aβ antibodies: (a–c) DPV plots of 20 μg mL⁻¹, 40 μg mL⁻¹ and 60 μg mL⁻¹ antibodies at each stage of sensing; (d–f) corresponding calibration curves of Ip as against log Aβ(1–42) concentrations. All data points are mean values of three independent electrodes. The error bars (calculated as the standard deviation) provide a measure of repeatability of the system (n = 3).