Metal Oxide Nanosystems As Chemoresistive Gas Sensors for Chemical Warfare Agents: A Focused Review

Abstract

The early and efficient detection of chemical warfare agents (CWAs), hazardous compounds resulting in fatal and irreversible health damages, is an issue of primary importance for security safeguard. Despite the efforts undertaken to date, the quest of lower detection limits, higher selectivity/stability, and faster recognition still represents a main bottleneck to effectively counteract such dreadful threats. This review aims at providing a survey on the developments undertaken in chemoresistive gas sensors based on metal oxide nanosystems for CWA recognition. The sensing mechanisms proposed in the literature, as well as the main reasons underlying the performance enhancement for functionalized/composite systems, are reviewed and discussed. The work summarizes key results achieved so far, and attempts to provide guidelines to overcome the main open problems. Efforts are devoted to delivering information on material properties/performance interplay, highlighting challenges in their fabrication and functional characterization. In fact, despite the advances made, a rational design and understanding of interfacial properties, as well as a perfect control over system growth, mandatory for commercial applications, are still missing. At the conclusion, a brief outlook on development prospects for future advancements is presented, endeavoring to provide a vision on the next necessary steps for an eventual technological implementation.

Molybdenum Carbide MXenes as Efficient Nanosensors toward Selected Chemical Warfare Agents

“…In this regard, various sensitive techniques including ion mobility spectrometry, , proton transfer reaction, and Raman spectroscopy have been developed to identify different CWAs in air. However, the above-mentioned techniques are mostly delicate, stationary, and expensive equipment confined to sophisticated labs, with time-consuming sample preparation protocols for CWA detection . The current need looks for a practically “field-able”, highly robust, portable, fast, simple-to-operate, and inexpensive detecting method to selectively identify the CWAs in both aqueous and non-aqueous media.…”

“…However, the above-mentioned techniques are mostly delicate, stationary, and expensive equipment confined to sophisticated labs, with time-consuming sample preparation protocols for CWA detection. 7 The current need looks for a practically "fieldable", highly robust, portable, fast, simple-to-operate, and inexpensive detecting method to selectively identify the CWAs in both aqueous and non-aqueous media.…”

Semiconductor Gas Sensors for Detecting Chemical Warfare Agents and Their Simulants

“…In the available literature, you can also find several review articles published in recent years on semiconductor sensors for detecting CWAs [ 19 , 20 , 21 , 22 ]. All of the above works concern only resistive sensors, mostly with metal oxide semiconductors (MOS sensors).…”

High-performance metal-oxide gas sensors based on hierarchical core–shell ZnFe2O4 microspheres for detecting 2-chloroethyl ethyl sulfide

“…The threat of chemical warfare remains a major concern, as indicated by the sarin attack that occurred in 1995 in a Japanese subway, [1][2][3] Syrian chemical weapon crisis in 2013, 4 assassination of Kim Jong-nam in Kuala Lumpur in 2017, 5 and Anglo-Russian "double agent" poisoning in 2018. 6 Therefore, the rapid and accurate detection and identication of chemical agents are essential for protecting human lives and property. Sulfur mustard is a vesicant that emits a garlic-like odor.…”