Table 3.

The data of the redox peaks of 10 mM K₃[Fe(CN)₆] in 0.1 M KCl at pH ≈ 7 on the bare SPE, SPCE/GPE/ZnO NPs, SPCE/LPE/ZnO NPs and SPCE/OPE/ZnO NPs at the scan rate of 100 mV/s.

Electrode	Ipa(µA)	Epa(V)	Ipc(µA)	Epc (V)	${\mathbf{E}}^{1/2}= \frac{{\mathit{E}}_{\mathit{p}\mathit{a}}+{\mathit{E}}_{\mathit{p}\mathit{c}}}{2}\left(\mathbf{V}\right)$	$\frac{{\mathit{i}}_{\mathit{p}\mathit{a}}}{{\mathit{i}}_{\mathit{p}\mathit{c}}}$	∆Ep(V)
SPE	85.17	0.19	−108.13	−0.02	0.09	0.79	0.21
SPE/ZnONPs/GPE	106.97	0.23	−94.98	0.06	0.15	1.13	0.17
SPE/ZnONPs/ LPE	125.03	0.32	−123.19	0.05	0.19	1.01	0.27
SPE/ZnONPs/OPE	175.08	0.38	−149.32	0.01	0.195	1.17	0.37