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Amperometric analysis systems with two or three require a potential of reference electrode stable in function of time. In this work we developed an Ag/AgCl pseudo-reference onto gold film on silicon substrate. The amperometric electrodeposition method utilized (constant potential) provided a uniform deposited film and a controlled process characterization. It allows us to obtain electrodes with excellent performance during fourteen consecutives day. The characterization in function of the chloride concentration and time were also presented.

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Adherence, homogeneity and chemical stability are key fabrication process parameters for Ag/AgCl reference pseudo-electrode. In this work, we were able to achieve reference electrodes over platinum, using an intermediated layer of gold to promote adhesion. The gold bath was prepared using sulfide and formaldehyde. The concentration of formaldehyde was adjusted to prevent electroless deposition during the electrodeposition. The obtained gold deposit was yellow, flat, 200 nm thick with good adherence and resistivity(6.02 μohms cm). Silver and silver chloride layers were deposited with a home-made galvanostatic equipment. The current density was ranged from 0.4 to 8.0 mA cm-2. Finally, a Nafion® 117 membrane was used to recover the AgCl film to avoid corrosion and to maximize lifetime of the reference electrode.