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Abstract
Current potentiometric sensing methods are limited to detecting nitrate at parts-per-billion (sub-micromolar) concentrations, and there are no existing potentiometric chemical sensors with ultralow detection limits below the parts-per-trillion (picomolar) level. To address these challenges, we integrate interdigital graphene ion-sensitive field-effect transistors (ISFETs) with a nitrate ion-sensitive membrane (ISM). The work aims to maximize nitrate ion transport through the nitrate ISM, while achieving high device transconductance by evaluating graphene layer thickness, optimizing channel width-to-length ratio (RWL), and enlarging total sensing area. The captured nitrate ions by the nitrate ISM induce surface potential changes that are transduced into electrical signals by graphene, manifested as the Dirac point shifts. The device exhibits Nernst response behavior under ultralow concentrations, achieving a sensitivity of 28 mV/decade and establishing a record low limit of detection of 0.041 ppt (4.8 × 10−13 M). Additionally, the sensor showed a wide linear detection range from 0.1 ppt (1.2 × 10−12 M) to 100 ppm (1.2 × 10−3 M). Furthermore, successful detection of nitrate in tap and snow water was demonstrated with high accuracy, indicating promising applications to drinking water safety and environmental water quality control. (Figure presented.)
Original language | English (US) |
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Article number | 137 |
Journal | Microsystems and Nanoengineering |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Dec 2024 |
Bibliographical note
Publisher Copyright:© The Author(s) 2024.
MRSEC Support
- Shared
PubMed: MeSH publication types
- Journal Article
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Dive into the research topics of 'Ultra-sensitive nitrate-ion detection via transconductance-enhanced graphene ion-sensitive field-effect transistors'. Together they form a unique fingerprint.Projects
- 1 Active
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University of Minnesota Materials Research Science and Engineering Center (DMR-2011401)
Leighton, C. (PI) & Lodge, T. (CoI)
THE NATIONAL SCIENCE FOUNDATION
9/1/20 → 8/31/26
Project: Research project