Multianalytes Sensing Probe: Fluorescent Moisture Detection, Smartphone Assisted Colorimetric Phosgene recognition and Colorimetric Discrimination of Cu2+and Fe3+ ions

Abstract An organic molecule-based sensor 4-((4-(dimethylamino)phenyl)diazenyl)-N-(quinolin-8-yl)benzenesulfonamide(MASP)able to detect multiple analytes such as moisture, warfare reagent (phosgene), divalent (Cu2+), and trivalent (Fe3+) has been reported. These analytes belong to the different classes of chemicals and barely interfere in the real sample. Fluorescence emission of MASP was observed due to the ESIPT mechanism, but it was inhibited by water. This phenomenon was utilized for moisture detection in DMSO and THF with the detection limit of 0.0032 % w/w and 0.0014 % w/w, respectively. The MASP was also employed for the colorimetric sensing (yellow to red) of phosgene in solution and gas with good selectivity and high sensitivity (LOD = 23 nM). The naked eye detection of MASP was incorporated with RGB color value to make use of MASP for the practical application using a smartphone as a portable analytical device. The distinct color change of divalent Cu2+ (yellow to colorless) and trivalent Fe3+ (yellow to red) observed with MASP also helps discriminate Cu2+ and Fe3+ among various cations.