Figure 5.
DPV response of the immunosensor to the increasing concentrations of target cis P-tau, from A to L: 0, 0.05, 0.2, 1, 5, 20, 50, 100, 500, 1000, 2000, 3000 pM, added to PBS (A) or human serum (B) containing the [Fe(CN)6]3−/4− as a redox probe. The relationship between the current response suppression and cis P-tau concentration was calculated from the DPV analysis of PBS (C) and human serum (D) samples. The insets show the linear calibration curve of the DPV current decrement versus the logarithm of complementary cis P-tau concentration (D) and the error bars represent standard deviations of the measurements (n = 3). The regression equation was obtained as ΔI (μA) = 0.2136 + 0.4042 log C (pM) and ΔI (μA) = 0.23326 + 0.3713 log C (pM) for PBS and human serum samples, respectively, where ΔI is the current decrement and C is the concentration of cis P-tau.