The SWASVs were recorded at different modified glassy carbon
electrodes. Fig. 1 shows the relevant voltammograms, obtained
by square wave anodic stripping voltammetry at the Bi–SbFE (a),
SbFE (b), BiFE (c), and the bare GCE (d) in hydrochloric acid solution
(pH 2.0) containing 50.0 g L−1 Cd(II). It can be seen that the
stripping peak current of Cd(II) at the SbFE (b), BiFE (c), or bare GCE
(d) was lower than that at the Bi–SbFE, illustrating that the Bi–SbFE
exhibited the sharpest and the highest stripping signal. The SWASV
response at the Bi–SbFE in the absence of Cd(II) is also shown in
Fig. 1 (see curve e) and there was no response at the Bi–SbFE in
the absence of Cd(II). Therefore, it demonstrated that Bi–Sb film
possesses very attractive electrochemical characteristics with high
sensitivity, compared with other three electrodes in this work. In
particular, the Bi–SbFE offers a well-defined stripping peak with
favorable signal-to-background characteristics, and is not prone to
oxygen interference.