Fine-Tuning an ISFET-Based Dual pH-Total Alkalinity Sensor for Operation in Seawater Using an Adjustable, Suspended Anode.

ABSTRACT: 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) exploration

SUBMITTER: Briggs EM 

PROVIDER: S-EPMC12560134 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature