Figure 35.

(A) PSA immunosensor using AuNPs–PAMAM for signaling and MWCNT/IL/CS as substrate, and transduction with HRP and thionine as immobilized mediator; (B) CVs of the immunosensor after incubation with PSA from O up to 80 ng mL⁻¹ in PBS, pH 7 + 2.5 mM H₂O₂. Insets, plots of the immunosensor response vs. PSA concentrations; (C) Nyquist curves for 2.5 mM [Fe(CN)₆]^3−/4− in 0.1 M KCl recorded at anti-PSA/AuNPs–PAMAM-dendrimer/MWCNTs/IL/Chit/GC after incubation with 5, 10, 15, 20 and 25 ng mL⁻¹ PSA. Insets are plot of R_ct vs. PSA concentration and the equivalent circuit used to fit the experimental impedance data. On the right, Nyquist curves for the immunosensor in the presence of 15 ng mL⁻¹ PSA and in serum spiked with 15 ng mL⁻¹ PSA. Adapted from [176], Copyright 2014, with permission from Elsevier.