Scheme 1.

Schematic of (A) fabrication of the immunosensor and (B) reaction occurring at the working electrode surface in 1 × PBS solution at pH 7.4 containing 1 mM[Fe(CN)6]3−, 0.1 M KCl, and 100 μM EDTA at scan rate 50 mV s−1.

Schematic of (A) fabrication of the immunosensor and (B) reaction occurring at the working electrode surface in 1 × PBS solution at pH 7.4 containing 1 mM[Fe(CN)6]3−, 0.1 M KCl, and 100 μM EDTA at scan rate 50 mV s−1.