Electrospun Nanofibers for Quartz Crystal Microbalance Gas Sensors: A Review

Abstract

In recent years, electrospun nanofibers made of various materials (e.g., polymers, composites, and semiconductors) have been extensively studied for the development of highly sensitive and selective gas sensors. These nanofibers possess unique three-dimensional (3D) interconnected porous structures that result in a large surface-area-to-volume ratio and high porosity. These properties have led to the widespread use of nanofibrous mats as active materials for mass-sensitive sensors, which use the gravimetric effect to measure the mass concentration of the adsorbed gases on their active surfaces. For this purpose, quartz crystal microbalance (QCM) has been considered as one of the most favorable mass-sensitive platforms because of its mature technology, low-cost production, fast sensing response, and highly flexible sensing area modification. This paper provides an overview of state-of-the-art QCM-based gas sensors that integrate electrospun nanofibers as their active materials. Several key parameters determining the sensor performance (e.g., sensitivity and limit of detection (LOD)) are summarized and discussed in relation to the current challenges. Finally, the outlook for future technological development is also provided.

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

“…Depending on their working principles and materials, several thin-film and micro-/nanoscale gas sensors can be employed as the main detecting components in the electronic nose, which include gravimetric sensors (e.g., surface acoustic wave resonators, resonant micro-/nanocantilevers, and quartz crystal microbalances) 31 – 40 , chemoresistive sensors (e.g., metal oxide semiconductor, polymer, two-dimensional material, and carbon-based sensors) 41 – 46 , colorimetric sensors (e.g., printable pastes and optical dye-functionalized washable threads) 47 , 48 , and optical sensors (e.g., visible and infrared micro-/nano-light-emitting diodes (micro-/nanoLEDs), plasmonic lasers, and femtosecond lasers) 49 – 56 . Among them, chemoresistive metal oxide semiconductor gas sensors have been favorable, especially for VOC detection, due to their excellent characteristics (i.e., low cost, short response time, simple measurement setup, high durability, and long lifetime) 57 .…”

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] .…”

Facile Fabrication of ZnO-ZnFe2O4 Hollow Nanostructure by a One-Needle Syringe Electrospinning Method for a High-Selective H2S Gas Sensor

“…In this study, the ZnO-ZnFe 2 O 4 hollow nanofibers were fabricated by the electrospinning process. The hollow nanofiber structure has advantages of high surface-to-volume area for inner/outer structure, high porosity, and good chemical/mechanical stability [21,22]. Furthermore, the fabrication route provides facile nanomaterial manipulations, high productivity, and controlled stable outputs from the homogeneous mixture of the metal precursor solution.…”