PEDOT:PSS-Facilitated Directionally 3-D Assembled MXene-Based Aerogel for High-Performance Chemoresistive Sensing & Breath Analysis

Sara Mohseni Taromsari; Meysam Salari; HaoTian Harvey Shi; Saeed Habibpour; Zia Saadatnia; Omid Aghababaei Tafreshi; Aiping Yu; Chul B Park; Hani E Naguib

doi:10.1002/adma.202406349

PEDOT:PSS-Facilitated Directionally 3-D Assembled MXene-Based Aerogel for High-Performance Chemoresistive Sensing & Breath Analysis

Adv Mater. 2024 Dec 20:e2406349. doi: 10.1002/adma.202406349. Online ahead of print.

Authors

Affiliations

¹ Department of Mechanical & Industrial Engineering (MIE), University of Toronto, Toronto, Ontario, M5S 3G8, Canada.
² Department of Mechanical & Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9, Canada.
³ Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
⁴ Department of Mechanical and Manufacturing Engineering, Ontario Tech University, Oshawa, Ontario, L1G 0C5, Canada.
⁵ Department of Materials Science & Engineering (MSE), University of Toronto, Toronto, Ontario, M5S 3E4, Canada.
⁶ Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, M5S 3E3, Canada.

PMID: 39707652
DOI: 10.1002/adma.202406349

Abstract

MXene has garnered growing interest in the field of electrochemistry, thanks to its unique electrical and surface characteristics. Nonetheless, significant challenges persist in realizing its full potential in chemoresistive sensing applications. In this study, a novel unidirectional freeze-casting approach for fabricating a Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-facilitated vertically aligned MXene-based aerogel with enhanced chemoresistive sensing properties was introduced. Firstly, the persistent challenge of poor gelation in MXene was addressed by formulating a nanohybrid of MXene and PEDOT:PSS, which acted as flexible conductive nanobinder. Employing a unique freeze-casting method, MXene flakes interconnected by PEDOT:PSS, were stabilized into a flexible, vertically aligned structure, leading to maximum surface exposure and enhanced robustness. The resulting 3-dimentional (3-D) aerogel exhibited a fast, heightened chemoresistive response of 7 to 50 parts per million (ppm) acetone and expanded the working range to between 10 parts per billion (ppb)-8000 ppm. Interfacial heterostructures formed between MXene and PEDOT:PSS, provided active sites, reduced activation energy, and enhanced selectivity. Modulated MXene bandgap, and its electron mobility further facilitated electron transfer, and enhanced signal strength. The sensor showed excellent biocompatibility and was also successfully employed as a breathalyzing tool, for on-demand alcohol consumption monitoring.

Keywords: MXene; PEDOT:PSS; aerogels; breath analysis; chemoresistive sensing; directional freeze‐casting.

Abstract

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