Electrospun ZnO Nanofiber Based Resistive Gas/Vapor Sensors -A Review

Abstract

Resistive zinc oxide (ZnO) sensors play a pivotal role in detecting various gases and vapors due to their high response, low cost, stability, tunability, and simple fabrication. Hence, it is necessary to know the recent status of research in resistive ZnO sensors. The sensitivity is determined by the reactions at the surface of the nanofiber (NF); therefore, the surface area defines the foremost sensor characteristics. Electrospun metal oxide NFs exhibit a high surface area and unique electrical properties that can be tuned, and they are highly sought as the materials for resistive gas sensors. So far, various strategies are adopted to improve the sensitivity and the selectivity of ZnO NFs. This review summarizes the recent methods utilized by various researchers to improve the sensitivity of the ZnO electrospun metal oxide NF-based resistive gas sensors. Also, it discusses the influence of process parameters on the structure and morphology of ZnO NFs, the mechanism of gas sensing and highlights its improvement through advanced methods. The sensitivity of the NF has been improved through tuning the structure and morphology of NFs and doping. Further, modification of NF sensitivity through functionalization, the addition of carbon nanomaterials, and high-energy irradiation are also discussed. Based on the recent literature, the performance of doped ZnO NF for various gas sensing is highlighted. The outcome of this review gives insight to academic researchers and industry for further investigation and development in resistive gas sensors and its applications.

High strength and anti‐freezing piezoresistive pressure sensor based on a composite gel

“…Flexible sensors have tremendous adhibitions in various different fields of energy storage devices, health‐care monitoring system, motion signal collection, robotic control, etc 1–10 . The pressure sensor is an integral part of flexible sensors with the ability to transduce pressure into directly observable or recordable electrical signals, 11–15 such as current, capacitance, and resistance, which makes an important role to monitor human movements and physical conditions 16–20 . Piezoresistive pressure sensors can discovered the regular change of the devices when pressure is applied by forming more conductive pathways 21 .…”

Controlled release of curcumin from coaxial electrospun nanofiber mats

“…[4][5][6][7][8][9][10] Finally, a nanofiber mat with a very large surface area per weight is formed on the surface of the collector, which can be used in several research fields such as biotissue engineering, composite materials, and sensors. [11][12][13][14][15][16][17][18][19] To date, nanofibers have been used to prepare DDSs. 20,21 However, fabricating DDSs with electrospun nanofibers using a single concentric nozzle is challenging because target drugs are released in large quantities at the initial stage of drug delivery.…”

“…In these devices, the polymer solution is extruded into an electric field that is subjected to a high voltage, forming nano‐ (nm) and micro‐sized (μm) fibers 4–10 . Finally, a nanofiber mat with a very large surface area per weight is formed on the surface of the collector, which can be used in several research fields such as biotissue engineering, composite materials, and sensors 11–19 …”

Highly Sensitive and Selective Sulfite Ion Sensor Based on Biochemically Stable Iodo‐Functionalized Coumarin Fluorophores

“…Since sulfites, in addition to behaving as an important signalling bio‐molecule, are being popularly employed globally as an essentially commercial “sulfiting” ingredient for the preservation of certain foods, beverages and pharmaceutical products against enzymatic and/or microbial spoilage, a strict monitoring of prescribed levels of this potent allergen is highly warranted [4] . A plethora of analytical techniques like titrations, electrochemistry, flow injection analysis and chromatography, for instance, have been deployed to detect sulfites and other polluting analytes in ecological samples [5–10] . Since such techniques usually warrant sophisticated and high‐maintenance instrumentation as well as complicated preparation procedures.…”

“…[4] A plethora of analytical techniques like titrations, electrochemistry, flow injection analysis and chromatography, for instance, have been deployed to detect sulfites and other polluting analytes in ecological samples. [5][6][7][8][9][10] Since such techniques usually warrant sophisticated and high-maintenance instrumentation as well as complicated preparation procedures. However, fluorescent probe assays are garnering an overwhelming demand primarily due to their quickness, exceptional discrimination, compassion, little price, uncomplicated recognition, respectable biocongenial performance and instantaneous detection power towards ecologically pertinent analytes.…”