Detection of Chemical Warfare Agents by Colorimetric Sensor Arrays

Abstract

We report the successful use of colorimetric arrays to identify chemical warfare agents (CWAs). Methods were developed to interpret and analyze a 73-indicator array with an entirely automated workflow. Using a cross-validated first-nearest-neighbor algorithm for assessing detection and identification performances on 632 exposures, at 30 min postexposure we report, on average, 78% correct chemical identification, 86% correct class-level identification, and 96% correct red light/green light (agent versus non-agent) detection. Of 174 total independent agent test exposures, 164 were correctly identified from a 30 min exposure in the red light/green light context, yielding a 94% correct identification of CWAs. Of 149 independent non-agent exposures, 139 were correctly identified at 30 min in the red light/green light context, yielding a 7% false alarm rate. We find that this is a promising approach for the development of a miniaturized, field-portable analytical equipment suitable for soldiers and first responders.

Recent Advances on Detection of Insecticides Using Optical Sensors

“…The colorimetric sensing technique has been proven to be an efficient analytical sensing of metallic cations, anions, drugs, pesticides, organic dyes and other toxic pollutants due to its easy fabrication [ 35 ], high sensitivity and selectivity [ 36 ], quick detection [ 37 ], as well as easy naked-eye sensing [ 38 ]. Since the colorimetric involved quantification of color from the reaction, then converting reaction behavior into visual color change is the key challenge for colorimetric platform manufacturing.…”

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

“…surface-enhanced Raman scattering (SERS)-based sensors, that recognize the target analytes utilizing the electromagnetic field enhancement of plasmonic substrates in combination with the chemical specificity of vibrational Raman spectroscopy; [69] iv) supramolecular sensors, involving the occurrence of non-covalent interactions between the sensing system and the analyte; [8] v) biosensors, in which the biological recognition component should be immobilized and have intimate contact with the transducer upon binding with the analyte, yielding ultimately qualitative and quantitative responses; [85] vi) liquid crystal-based sensors, that, upon contact with the analyte, yield orientational (and thus optical) responses; [86] vii) colorimetric and fluorescence sensors, more investigated than the previously mentioned ones, enabling gas detection through the measurement of color/luminescence variations. [4,9,12,[15][16][17]23,25,59,87] In this broad context, chemoresistive gas sensors based on nanostructured semiconducting oxides yield various important advantages, encompassing moderate processing costs, compatibility with silicon technology, miniaturization possibility, simple operation, and high sensitivity. [29,30,47,56,57,60,75,[88][89][90][91] The general working principle of such sensors has already been well described in the literature.…”

“…[28,91] The latter is indeed a very critical requirement not only to prevent the occurrence of false alarms, but also because the missed CWA detection may result in health damages and eventually lead to death. [4,23,24,39,58,70,87,112] As a matter of fact, it is difficult to identify general guiding principles/strategies enabling to improve these parameters, and, in particular, the sensor selectivity, without adopting the use of electronic noses/sensor arrays. So far, research efforts performed in this direction have been mainly performed on an empirical basis.…”

“…[ 1 ] The line from the very famous song sounds like a perfect slogan for the actual crusade toward a peaceful world, but, even after a so long time, this goal is unfortunately still far from being achieved. Chemical weapons [(chemical warfare agents (CWAs)] developed to kill or incapacitate potential enemies [ 2–5 ] were introduced for military purposes in World War I (1915–1918) and killed over 90 000 people. [ 6,7 ] Subsequently, during the 1930s, Germans manufactured nerve agents [ 8 ] which were further targeted by the British (1950s) and weaponized by the Americans.…”

“…[8,13,[23][24][25][26][27] Examples in this regard include nerve agents release in Japan (Matsumoto, 1994 andTokyo, 1995), [2][3][4][36][37][38][39][40] Al Qaeda threats, [41] the assassination of Kim Jong-Nam, the half-brother of North Korean leader Kim Jong-un, at Kuala Lumpur Airport (Malaysia) in 2017, [42,43] and the poisoning of the Russian spy Sergei Skripal and his daughter in Salisbury (UK) in 2018. [44] Highly lethal CWAs, that can be classified into four main categories (see Table 1; nerve, blood, vesicant, and choking agents [2,4,5,10,17,28,[45][46][47][48] ) can burn and blister skin/eyes, enter into the body in blood and attack the nervous system. [9,12,15,16,36,38,[49][50][51][52][53] As a consequence, increasing worldwide efforts have been aimed at their disposal, destruction [10,11,19,…”