@article{discovery10185432,
            note = {{\copyright} 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).},
       publisher = {Elsevier BV},
           month = {January},
            year = {2024},
           title = {An electroplated Ag/AgCl quasi-reference electrode based on CMOS top-metal for electrochemical sensing},
         journal = {Electrochimica Acta},
          volume = {477},
        keywords = {CMOS,
Reference electrode,
Electroplating,
Electrochemical,
Electroless},
          author = {Keeble, Lewis and Jaccottet, Arthur and Ma, Daryl and Rodriguez-Manzano, Jesus and Georgiou, Pantelis},
            issn = {0013-4686},
             url = {http://dx.doi.org/10.1016/j.electacta.2024.143780},
        abstract = {The integration and mass-production of reference electrodes for CMOS-based electrochemical sensing systems
pose a challenge for the accessibility and commercial-viability of such devices. In this paper, a method of
electroplating an Ag/AgCl quasi-reference electrode using CMOS top-metal as a base is presented for the first
time. The aluminium bond-pad of a CMOS microchip was zincated, an electroless nickel immersion gold layer
applied, and a thick silver layer electroplated and chemically chlorinated. The resulting reference electrode was
able to provide a stable potential with a drift rate of 0.3 mV/h for up to 18 h. This validates the approach of a
fully electroplated bond-pad reference electrode, which offers simplified post-processing and greater scalability
of production. Further work towards an entirely electroless process is envisaged}
}