Fig. 2. (A) UV–Vis spectra of (a) FNP-TBA and (b) TBA. Inserted TEM images of FNP@PEI (upper) and FNP-TBA (lower); (B) Plots of anodic peak current of the FNP-tagged E-AB sensor
vs. scan rate. Inset of CVs was a) before and b) after the incubation with 40 nM thrombin. (C) Nyquist plots of (a) Au, (b) FNP-TBA/Au, (c) FNP-tagged aptasenor, (d) c) after binding
with TMB. Inset of AFM images of FNP-tagged aptasensor c) before and d) after binding of TMB (40 nM). (D) Plots for the percentage of current suppression responsed with TMB at
different concentrations by DPV. Inset of DPV responses and Histograms of the selectivity of the aptasensor. Three different solutions contained: (1) 2.5 μM BSA, (2) 2.5 μM BSA and
20 nM TMB, and (3) 20 nM TMB. These data and error bars represented the average value and the standard deviation of measurements taken with three independently fabricated
sesnsors.