Wireless, Flexible, Ion-Selective Electrode System for Selective and Repeatable Detection of Sodium

• Type of Material: Article
• Authors: Hyo-Ryoung Lim, Georgia Institute of Technology; Yun-Soung Kim, Georgia Institute of Technology; Shinjae Kwon, Georgia Institute of Technology; Musa Mahmood, Georgia Institute of Technology; Young-Tae Kwon, Georgia Institute of Technology; Yongkuk Lee, Wichita State University; Soon Min Lee, Yonsei University; Woon-Hong Yeo, Emory University
• Language: English
• Date: 2020-06-01
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2020 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/s20113297
• Title of Journal or Parent Work: SENSORS
• Volume: 20
• Issue: 11
• Start Page: 1
• End Page: 11
• Grant/Funding Information: This work was partially supported by the American Heart Association (grant 19IPLOI34760577) and a faculty research grant of Yonsei University College of Medicine (6-2019-0169).; Electronic devices in this work were fabricated at the Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure, which is supported by the National Science Foundation (grant ECCS-1542174).; We acknowledge a research fund from the Marcus Foundation, the Georgia Research Alliance, and the Georgia Tech Foundation through their support of the Marcus Center for Therapeutic Cell Characterization and Manufacturing (MC3M) at Georgia Tech.
• Keywords: Engineering, Electrical & Electronic; Science & Technology; Physical Sciences; GRAPHENE; Technology; SOLID-CONTACT; Instruments & Instrumentation; wireless flexible sensor system; POLYMER; COPPER(II); TRANSDUCER; Engineering; Chemistry, Analytical; SILICONE-RUBBER; LAYER; PLATFORM; POTENTIOMETRIC SENSORS; ion-selective electrode; sodium detection; CARBON; Chemistry; carbon-polymer composite transducer
• Research Categories: Engineering, Biomedical

Abstract

Wireless, flexible, ion-selective electrodes (ISEs) are of great interest in the development of wearable health monitors and clinical systems. Existing film-based electrochemical sensors, however, still have practical limitations due to poor electrical contact and material–interfacial leakage. Here, we introduce a wireless, flexible film-based system with a highly selective, stable, and reliable sodium sensor. A flexible and hydrophobic composite with carbon black and soft elastomer serves as an ion-to-electron transducer offering cost efficiency, design simplicity, and long-term stability. The sensor package demonstrates repeatable analysis of selective sodium detection in saliva with good sensitivity (56.1 mV/decade), stability (0.53 mV/h), and selectivity coefficient of sodium against potassium (−3.0). The film ISEs have an additional membrane coating that provides reinforced stability for the sensor upon mechanical bending. Collectively, the comprehensive study of materials, surface chemistry, and sensor design in this work shows the potential of the wireless flexible sensor system for low-profile wearable applications.