Room-temperature ppb-level trimethylamine gas sensors functionalized with citric acid-doped polyvinyl acetate nanofibrous mats

Abstract

Conventional chemoresistive gas sensors based on inorganic metal oxide semiconductors work typically at an elevated temperature (200 – 500 °C) to facilitate the chemical reaction between the target gas molecules...

Fast and noninvasive electronic nose for sniffing out COVID-19 based on exhaled breath-print recognition

“…This gas sensing con guration utilizing microsyringe for vapor injection has already been used in our former experiments for other VOC sensor types (e.g., nano berfunctionalized QCMs). 36,70,71 Acetone was chosen as a VOC model because it is not only produced in the rebreathed breath (0.8 to 2.0 ppm) 72 but also indicated as one of the signi cant breath-borne COVID-19 biomarkers based on the study by Chen et al 62 Moreover, in the clinical practices, breath-containing acetone has also been extensively examined to diagnose some other diseases (i.e., lung cancer, diabetes mellitus, starvation, and ketogenic diet). 73 From the obtained measurement results shown in Figures S2b and c, the S3 and S7 sensors (or their extracted features of F3 and F7) demonstrated the poorest responses toward acetone vapors.…”

Hybrid learning method based on feature clustering and scoring for enhanced COVID-19 breath analysis by an electronic nose

“…It is a device combining broad-spectrum chemical sensor array with a gas sampling chamber and machine learning to mimic human olfactory perception and provide a digital breathprint of the VOCs. Among other various gas sensor types (e.g., gravimetric microelectromechanical system (MEMS) and optical, capacitive, and photoacoustic gas sensors [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] ), chemoresistive gas sensors based on the metal-oxide semiconductor (MOS) have been widely used as the main components of the e-nose considering their advantageous properties (i.e., high sensitivity, mature material synthesis technology, high robustness, low fabrication cost, short response time, and simple sensing method) [41] .…”

Tailoring the molecular weight of polymer additives for organic semiconductors

“…29,30 The enhanced π–π stacking in TIPS pentacene is attributed to higher charge transport. 31 These research endeavors have opened up vast opportunities for organic semiconductors to be applied in high performance organic electronic devices such as organic thin film transistors, 32–35 organic gas sensors, 36–38 photovoltaic devices 39–41 and logic circuits. 42–44 In this section, we will review the important studies that investigated the solution processability and charge carrier mobility of organic semiconductor based thin film transistors, as well as their application in fabricating organic gas sensors.…”