eprintid: 10185432 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/18/54/32 datestamp: 2024-01-15 16:13:42 lastmod: 2024-01-15 16:13:42 status_changed: 2024-01-15 16:13:42 type: article metadata_visibility: show sword_depositor: 699 creators_name: Keeble, Lewis creators_name: Jaccottet, Arthur creators_name: Ma, Daryl creators_name: Rodriguez-Manzano, Jesus creators_name: Georgiou, Pantelis title: An electroplated Ag/AgCl quasi-reference electrode based on CMOS top-metal for electrochemical sensing ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F45 keywords: CMOS, Reference electrode, Electroplating, Electrochemical, Electroless note: © 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/). 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 date: 2024-01 date_type: published publisher: Elsevier BV official_url: http://dx.doi.org/10.1016/j.electacta.2024.143780 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2139534 doi: 10.1016/j.electacta.2024.143780 lyricists_name: Jaccottet, Arthur lyricists_id: AJACC75 actors_name: Jaccottet, Arthur actors_id: AJACC75 actors_role: owner full_text_status: public publication: Electrochimica Acta volume: 477 article_number: 143780 issn: 0013-4686 citation: Keeble, Lewis; Jaccottet, Arthur; Ma, Daryl; Rodriguez-Manzano, Jesus; Georgiou, Pantelis; (2024) An electroplated Ag/AgCl quasi-reference electrode based on CMOS top-metal for electrochemical sensing. Electrochimica Acta , 477 , Article 143780. 10.1016/j.electacta.2024.143780 <https://doi.org/10.1016/j.electacta.2024.143780>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10185432/1/Keeble%20%282024%29%20-%20An%20electroplated%20AgAgCl%20quasi-reference%20electrode%20based%20on%20CMOS%20top-metal%20for%20electrochemical%20sensing.pdf