Characterization of Room-Temperature Ionic Liquids to Study the Electrochemical Activity of Nitro Compounds

Abstract

Over the past few years, room-temperature ionic liquid (RTIL) has evolved as an important solvent-cum-electrolyte because of its high thermal stability and excellent electrochemical activity. Due to these unique properties, RTILs have been used as a solvent/electrolyte/mediator in many applications. There are many RTILs, which possess good conductivity as well as an optimal electrochemical window, thus enabling their application as a transducer for electrochemical sensors. Nitroaromatics are a class of organic compounds with significant industrial applications; however, due to their excess use, detection is a major concern. The electrochemical performance of a glassy carbon electrode modified with three different RTILs, [EMIM][BF4], [BMIM][BF4] and [EMIM][TF2N], has been evaluated for the sensing of two different nitroaromatic analytes: 2,6-dinitrotoluene (2,6 DNT) and ethylnitrobenzene (ENB). Three RTILs have been chosen such that they have either a common anion or cation amongst them. The sensory response has been measured using square wave voltammetry (SQWV). We found the transducing ability of [EMIM][BF4] to be superior compared to the other two RTILs. A low limit of detection (LOD) of 1 ppm has been achieved with a 95% confidence interval for both the analytes. The efficacy of varying the cationic and anionic species of RTIL to obtain a perfect combination has been thoroughly investigated in this work, which shows a novel selection process of RTILs for specific applications. Moreover, the results obtained from testing with a glassy carbon electrode (GCE) have been replicated using a miniaturized sensor platform that can be deployed easily for on-site sensing applications.

ZENose (ZIF-Based Electrochemical Nose) Platform for Noninvasive Ammonia Detection

“…[BMIM]­[BF 4 ] was used as an electrolyte for gas sensing, and 100 μL was drop-cast on the electrode surface such that it covered all three electrodes. A thin layer of room temperature ionic liquid (RTIL)-Fc@ZIF-8 over the electrode surface allows for the easy diffusion of the target gas and reduces interference, thereby performing as an excellent transducer for signal transduction . CV was performed to understand the interaction of the ammonia gas with the modified electrode interface, and CV was performed at −1 to +1 V with an increasing scan rate from 25 to 250 mV/s for ammonia sensing at 400 ppb (Figure ).…”

“…A thin layer of room temperature ionic liquid (RTIL)-Fc@ZIF-8 over the electrode surface allows for the easy diffusion of the target gas and reduces interference, thereby performing as an excellent transducer for signal transduction. 47 CV was performed to understand the interaction of the ammonia gas with the modified electrode interface, and CV was performed at −1 to +1 V with an increasing scan rate from 25 to 250 mV/ s for ammonia sensing at 400 ppb (Figure 6). The peaks of CV at 0.25 and 0.45 V represented the reduction/oxidation of ferrocene, respectively.…”

E.Co.Tech-electrochemical handheld breathalyzer COVID sensing technology

“…The electrode sensor design employed in this study has previously been used by our group for studying amperometric gas sensing phenomenon 29 , 30 , 36 – 38 . A gold interdigitated electrode (IDE) design was chosen for sensing of target gas analyte as gold offers increased electric field confinement owing to the reduced microelectrode geometry.…”

“…Room Temperature Ionic Liquids (RTILs) are widely employed as a sensing material for surface modification of electrodes to allow sensing of various gases and VOC 26 – 28 . We have demonstrated the use of RTIL as a signal transducer for the detection of trace VOCs and gases 21 , 29 , 30 . Moreover, the current breath analyzer-based technology developed for COVID-19 detection include magnetic sensors 31 , optical sensors 32 and electrochemical sensors 33 .…”

ZEUS (ZIF-based electrochemical ultrasensitive screening) device for isopentane analytics with focus on lung cancer diagnosis

“…Electrochemical transduction mechanism is used for the development of Point of Care (PoC) platforms as they are robust, sensitive and specic in nature especially for gas and VOC sensing applications. 19,21,53,58 We used commercially available carbon SPE as the electrode system for sensing application as it can be easily integrated into a microelectronics platform. The electrode design involves concentric three electrode system wherein the WE and the CE are made of carbon and the RE is made of Ag/AgCl.…”