The amperometric responses were measured at the OSi@CS/GCE
and Pt-Au-OSi@CS/GCE. The corresponding typical current–time
curves were shown in Fig. 5. As can be observed, drastic increases
in the response currents were observed at the Pt-Au-OSi@CS/GCE
with the addition of the CC (Fig. 5A curve a) and HQ (Fig. 5B
curve a). The reduction currents linearly increased with the concentration
increasing. The sensor showed linear responses for
wide ranges of concentrations of CC 0.06–90.98 M and HQ
0.03–172.98 M with the detection limits of 0.02 M and 0.01 M,
respectively. The linear equations for CC and HQ were expressed
as ICC (A) =
−2.956–0.06080 CCC (M) (R = 0.9966) and IHQ
(A) =
−2.943–0.03964 CHQ (M) (R = 0.9979), respectively. Inset
showed the corresponding calibration curve, respectively. However,
the OSi@CS/GCE showed relatively small current responses to CC