The GC/AuNPs/E was characterized using AFM and SEM analyses.
The AFM topographic image of GC/AuNPs/E (Fig. 1a) shows the homogeneous distribution of AuNPs, which had a cross section(Fig. 1b) with an average size of 75 nm and a roughness of 24.7 nm.
The SEM analysis indicated a homogeneous distribution of AuNPs with an average size of 75.82 ± 20 nm, which is similar to the results obtained using AFM and EDX confirming the presence of gold on the electrode surface (Fig. 1c and d).