Selective colorimetric sensors and diagnostic microfiber yarn for carbonyl groups via ion-pairing dyes with plural chromatic behaviors

Abstract

An ideal chemo-responsive dye requires several essential features, including a facile preparation method, a broad range of dynamic color changes, and colorimetric responses to multiple stimuli. Herein, we present a simple and reliable procedure for synthesis of chemo-responsive dye from ion-pair formation of oppositely charged dyes. The ion-pairing dye exhibits various colorimetric responses to pH levels and amine concentrations, indicating that the dye has plural chromatic behaviors and wide visible spectrum: ‘halochromism’ and ‘solvatochromism’. Due to this, our colorimetric sensors can selectively identify various carbonyl groups such as ketone, aldehyde, and carboxylic acids, in which the detection limits range from a minimum of 0.019 to a maximum of 2.506 ppm. Furthermore, the sensing array composed of a single ion-pairing dye enables the generation of easily identifiable color-patterns as unique fingerprints for each carbonyl groups across a range of gas levels. Based on these colorimetric responses to carbonyl groups, we develop dye-loaded microfiber yarn for biomarker diagnosis, which can check for the presence of acetone gas in the exhaled breaths and confirm whether an individual is in the optimal ketosis state or not.