Effective Strategy for Colorimetric and Fluorescence Sensing of Phosgene Based on Small Organic Dyes and Nanofiber Platforms

Abstract

Three o-phenylendiamine (OPD) derivatives, containing 4-chloro-7-nitrobenzo[c][1,2,5]oxadiazole (NBD-OPD), rhodamine (RB-OPD), and 1,8-naphthalimide (NAP-OPD) moieties, were prepared and tested as phosgene chemosensors. Unlike previously described methods to sense this toxic agent, which rely on chemical processes that transform alcohols and amines to respective phosphate esters and phosphoramides, the new sensors operate through a benzimidazolone-forming reaction between their OPD groups and phosgene. These processes promote either naked eye visible color changes and/or fluorescence intensity enhancements in conjunction with detection limits that range from 0.7 to 2.8 ppb. NBD-OPD and RB-OPD-embedded polymer fibers, prepared using the electrospinning technique, display distinct color and fluorescence changes upon exposure to phosgene even in the solid state.

Colorimetric Detection of Thiophenol Based on a Phenolphthalein Derivative and Its Application as a Molecular Logic Gate

“…Among the various analytical methods, colorimetric chemosensors or chemodosimeters can provide the most convenient and effective way of sensing a specific analyte, since naked‐eye detection is possible without any aid of an instrument …”

“…[4][5][6][7][8][9][10][32][33][34][35][36][37][38] Among the various analytical methods, colorimetric chemosensors or chemodosimeters can providet he most convenient and effective way of sensing as pecific analyte, since nakedeye detection is possible without any aid of an instrument. [11][12][13][14][15] On the other hand, molecularl ogic gates using chemosensors or chemodosimeters have drawn al ot of attention. [16][17][18][19][20][21][22][23][24][25] Fluorescent and colorimetric chemosensors or chemodosimeters using variousi nputs were developedt oc onstruct various types of molecular logic gates.…”

Colorimetric Nanofibers as Optical Sensors

“…Nevertheless, the authors also successfully applied their sensor to seawater samples, proving the applicability of the colorimetric nanofibers. Much faster response times (1 to 2 minutes) combined with low detection limits (0.7 to 2.8 ppb) were achieved by Yoon et al for the detection of phosgene vapors by doping polyethylene oxide nanofibers with three different o ‐phenylendiamine derivatives containing 4‐chloro‐7‐nitrobenzo[c][1,2,5]oxadiazole (NBD‐OPD), rhodamine (RB‐OPD) and 1,8‐naphtalimide (NAP‐OPD) . Only NBD‐OPD and RB‐OPD showed a clear visual color change respectively from orange to pale yellow and from colorless to pink due to the formation of the benzimidazolene derivatives upon detection of triphosgene gas.…”

A Powerful Turn‐On Fluorescent Probe for Phosgene: A Primary Amide Strategically Attached to an Anthracene Fluorophore

“…The development of portable test strips for real time sensing has made this method all the more attractive and given it an edge over other sensing methods targeted toward phosgene. It is no surprise thus that a plethora of fluorescent chemodosimetric sensors for phosgene exist many of which have utilized the phosgene mediated acylation of amines . In each of these cases the acylation reaction has culminated in a measurable fluorescence spectral change through the involvement of a fluorescence signalling species such as courmarin, rhodamine, benzothiazole etc.…”