Figure 4

SWV responses of the modified procedure of electrodes in 0.1 M PBS and 5 mM H₂O₂ (pH 7.0). (a) bare GCE; (b) poly(thionine)-Au nanocomposite modified GCE; (c) anti-CYFRA21-1/poly(thionine)-Au nanocomposite modified GCE; (d) blocked with 1% BSA; (e) modified glassy carbon electrode after incubation with 0.5 ng mL⁻¹ CYFRA21-1.