Ionogels Based on a Single Ionic Liquid for Electronic Nose Application

Abstract

Ionogel are versatile materials, as they present the electrical properties of ionic liquids and also dimensional stability, since they are trapped in a solid matrix, allowing application in electronic devices such as gas sensors and electronic noses. In this work, ionogels were designed to act as a sensitive layer for the detection of volatiles in a custom-made electronic nose. Ionogels composed of gelatin and a single imidazolium ionic liquid were doped with bare and functionalized iron oxide nanoparticles, producing ionogels with adjustable target selectivity. After exposing an array of four ionogels to 12 distinct volatile organic compounds, the collected signals were analyzed by principal component analysis (PCA) and by several supervised classification methods, in order to assess the ability of the electronic nose to distinguish different volatiles, which showed accuracy above 98%.

Tackling Humidity with Designer Ionic Liquid‐Based Gas Sensing Soft Materials

“…The response times of our electrical system to VOCs are in the order of 0.02–5 s, which are comparable to other works performed with different gelatin-based ionomaterials, [ 39 , 43 ] where response times of 5 s were obtained when the materials were exposed to similar VOCs to those tested in our work (e.g., acetone, ethanol, hexane toluene). This is a very fast response compared to that reported recently metal oxide gas sensors, that can range between 30 and 80 s [ 44 ] or even take a few minutes to respond [ 45 ] to ethanol.…”

Chemiresistive Sensor Arrays for Gas/Volatile Organic Compounds Monitoring: A Review

“…[ 62 ] In yet another example, Goncalves et al used the drop‐casting technique and designed an array (e‐nose) to detect acetone at room temperature, as seen in Figure 2C. [ 45 ] The e‐nose developed showed a high response to acetone in the presence of other cross‐reactive gases like chloroform, ethanol, toluene, and hexane.…”

“…C) Preparation of gas sensor array via-drop casting of ionic liquid in between copper interdigitated electrodes (IDE). [45] in Figure 2C. [45] The e-nose developed showed a high response to acetone in the presence of other cross-reactive gases like chloroform, ethanol, toluene, and hexane.…”

“…[45] in Figure 2C. [45] The e-nose developed showed a high response to acetone in the presence of other cross-reactive gases like chloroform, ethanol, toluene, and hexane.…”

“…Copyright 2019, American Chemical Society. C) Preparation of gas sensor array via-drop casting of ionic liquid in between copper interdigitated electrodes (IDE) [45].…”