In addition, Figure 5 shows a Tafel plot for the HCl[O.sub.4] media, revealing that the current density increases as a function of the imposed potential, which shows that detection of the faradaic current
began above 2.3 V, which is consistent with the response of the BDD because this type of electrode requires higher overpotentials to oxidize water .
In this potential region, no significant Faradaic current
was observed, and the current was proportional to the scanning rate.
Due to this property, the ionic adsorption on gold is low, thus lowering the faradaic current
transfer  and the electrical double layer (EDL) formation .
Carbon paste electrodes exhibit low faradaic current
, wide potential range for operation, low reactivity, easily renewable surface and suitability to the construction of relatively small electrodes.
The highest voltage of the initial light emission and intensity were thickness of 30 [micro]m due to the thickness more than 30 [micro]m cause the mean free path of the electron area on the surface of ZnS:Cu phosphor is suitable and the efficient faradaic current
flow through at ZnS:Cu phosphor are decreased [27-29].
The electrode modified with PMMA-block-PDMAEMA also showed a small contribution to the faradaic current
in the buffer solution, which seems to persisted even with the entrapped protein.
Nevertheless, below 2.5 g/L of FOS, no faradaic current
for the marker ion was observed (data not shown).