biostudies-literatureUnknown10(10)Briggs EMIn this study, we present a re-envisioned design of an ion-sensitive field-effect transistor (ISFET)-based solid-state sensor for measuring pH and total alkalinity of seawater with electrolytically generated titrant. The original design requires either custom nanofabrication of ISFET wafers or back-end processing of fully fabricated ISFETs. Instead, we assembled all "off-the-shelf" parts to demonstrate the same measurement principle but with the titrant-generating electrode suspended orthogonal to the pH-sensing region of the ISFET rather than being physically deposited on the face of the chip. This offers many benefits including (1) avoiding disruption the pH functionality of the ISFET; (2) enabling the assessment of anode-gate distance sensitivity from a single ISFET; and (3) explorationACS sensors8045-8052https://www.ebi.ac.uk/biostudies/studies/S-EPMC12560134biostudies-literatureFine-Tuning an ISFET-Based Dual pH-Total Alkalinity Sensor for Operation in Seawater Using an Adjustable, Suspended Anode.PMC12560134Martz TRBriggs EMfalseFine-Tuning an ISFET-Based Dual pH-Total Alkalinity Sensor for Operation in Seawater Using an Adjustable, Suspended Anode.In this study, we present a re-envisioned design of an ion-sensitive field-effect transistor (ISFET)-based solid-state sensor for measuring pH and total alkalinity of seawater with electrolytically generated titrant. The original design requires either custom nanofabrication of ISFET wafers or back-end processing of fully fabricated ISFETs. Instead, we assembled all "off-the-shelf" parts to demonstrate the same measurement principle but with the titrant-generating electrode suspended orthogonal to the pH-sensing region of the ISFET rather than being physically deposited on the face of the chip. This offers many benefits including (1) avoiding disruption the pH functionality of the ISFET; (2) enabling the assessment of anode-gate distance sensitivity from a single ISFET; and (3) exploration2025-01-01T00:00:00Z2025 Oct2026-05-14T03:18:51.038Z2026-05-14T03:12:27.774ZS-EPMC125601344101605710.1021/acssensors.5c02765