High-sensitivity and energy-efficient chloride ion sensors based on flexible printed carbon nanotube thin-film transistors for wearable electronics

• Published in: Talanta (Oxford) Vol. 276; p. 126285
• Main Authors: Li, Benxiang, Sui, Nianzi, Li, Min, Gu, Weibing, Yang, Wenming, Xu, Wanzhen, Zhao, Jianwen
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.08.2024
• Subjects: Chloride ion sensors; Flexible electronics; Health monitoring; Printed electronics; Single-walled carbon nanotube thin-film transistors (SWCNT-TFTs); Health monitoring; Flexible electronics; Single-walled carbon nanotube thin-film transistors (SWCNT-TFTs); Printed electronics; Chloride ion sensors
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2024.126285

The advent of flexible single-walled carbon nanotube thin-film transistors (SWCNT-TFTs) has transformed electronics, providing significant benefits like low operating voltage, reduced power consumption, cost-effectiveness, and improved signal amplification. This study focuses on leveraging these attributes to develop a novel flexible high-sensitivity and energy-efficient chloride ion sensors based on printed flexible SWCNT-TFTs utilizing polymers-sorted semiconducting SWCNTs (sc-SWCNTs) as the active layers and ion liquids-poly(4-vinylphenol as dielectric layers along with the evaporated deposition of aluminum electrodes and printed silver electrodes as the gate and source-drain electrodes, respectively. The sensors exhibit several operational advantages, including low voltage requirements (≤1 V), rapid response speed (5.32 s), significant signal amplification (Up to 702.6 %), low power consumption (0.31 μJ at 1 mmol chloride ion), good repeatability, high sensitivity for both low and high concentrations of chloride ion (up to 100 mmol/L) and excellent mechanical flexibility (No obvious changes after bending for 10,000 times with a 5 mm radius). The detection mechanism of chloride ions was analyzed using X-ray Photoelectron Spectroscopy (XPS). It was found that chloride ions react with silver nanoparticles (AgNPs) to form silver chloride (AgCl) on printed electrodes, impeding carrier transport and reducing the currents in SWCNT TFTs. Importantly, our sensors' compatibility with smart devices allows for real-time monitoring of chloride ion levels in human sweat, offering significant potential for daily health monitoring. High-sensitivity and energy-efficient chloride ion sensors based on flexible carbon nanotube thin-film transistors for real-time monitoring chloride ions in human sweat. [Display omitted] •Innovative design of high-sensitivity and energy-efficient chloride ion sensors.•Exhibiting rapid response speed and excellent mechanical flexibility.•Compatibility with smart devices for health monitoring applications.•Enabling real-time monitoring of chloride ions in human sweat.