The strong collaboration between the Centre for Textile Science and Engineering (CTSE) of the Department of Materials, Textiles and Chemical Engineering (MaTCh) and the Supramolecular Chemistry (SC) group of the Department of Organic and Macromolecular Chemistry (Faculty of Sciences) has led to a breakthrough in the development of colorimetric nanofibrous sensors for the detection of acid and alkaline compounds in safety as well as biomedical contexts, which was published as a cover article in the leading journal Advanced Functional Materials (IF: 18.808), entitled “Eco-Friendly Colorimetric Nanofiber Design: Halochromic Sensors with Tunable pH-Sensing Regime Based on 2-Ethyl-2-Oxazoline and 2-n-Butyl-2-Oxazoline Statistical Copolymers Functionalized with Alizarin Yellow R”.

Colorimetric nanofibrous sensors are highly porous coatings or membranes consisting of sub-micron fibers that are functionalized with dyes to change color upon the presence of specific acid or alkaline compounds such as biogenic amines, thereby providing the user with a visual warning about these compounds. Prof. Karen De Clerck, dr. Ella Schoolaert, prof. Richard Hoogenboom, Ronald Merckx and the other UGent authors*  worked together to design a universal platform, based on 2-n-butyl-2-oxazoline and 2-ethyl-2-oxazoline statistical copolymers and derivatives of the alizarin yellow dye, that allows to manipulate the pH at which the color change is triggered. The colorimetric nanofibers were produced by ecological friendly electrospinning, one of the core research activities within MaTCh-CTSE. The combination of understanding the underlying chemical mechanisms and clever material design resulted in the unprecedented possibility to produce, from a single dye-polymer system, a wide variety of colorimetric nanofibrous sensors of which the colorimetric response can be tuned to match the needs of a specific application. For example, the authors showed that the sensor sensitivity can be tuned to detect trimethylamine at concentrations as low as 5 ppb. These visual sensors could potentially be used for personal breath analysis, as trimethylamine in breath might be a marker for underlying diseases.

*The authors: dr. Ella Schoolaert (CTSE), Ronald Merckx (SC group), Jana Becelaere (CTSE), Serge Rijssegem (CTSE), prof. Richard Hoogenboom (SC group) and prof. Karen De Clerck (CTSE). The cover was designed by Timo Meireman (CTSE).