Detection and Distinction of DNT and TNT with a Fluorescent Conjugated Polymer Using the Microwave Conductivity Technique

Abstract

We report the detection and distinction of dinitrotoluene (DNT) and trinitrotoluene (TNT) by the microwave conductivity technique using a cyclopentadithiophene-bithiazole-based polymer (CPDT-BT) as sensor. Although the conventional fluorescence quenching experiments showed just "turn OFF" of the polymer fluorescence for both DNT and TNT, time-resolved microwave conductivity (TRMC) revealed that the photoconductivity of the polymer, which is "turned OFF" in the pristine state became "ON" in the presence of DNT but remained "OFF" with TNT, allowing easy distinction between them. Moreover, the decay rate of the transient kinetics was found to be sensitive to the DNT concentration, implementing a unique method for the determination of unknown DNT concentration. The observations are discussed in viewpoint of charge separation (CS) and formation of charge transfer (CT) complex by considering deeper LUMO of TNT than DNT calculated from the DFT method. This study brings out a novel technique of speedy detection and distinction of environmentally important analytes, an alternative to the fluorescence quenching.

Strong Fluorescence Film of Dicyano Oligo(P‐Phenylenevinylene) Supramolecular Gel for Aromatic Amine Vapors Detection

“…Given these investigations, the organogelator fluorophores commonly possess low HOMO energy levels to allow electron transfer from organic amines at ground state to the fluorophore at excited state . While many fluorophores stack together to form one‐dimensional (1D) aggregates in their gel phases, the fluorescence of many adjacent fluorophores are quenched through exciton diffusion when an analyte molecule gives an electron to one fluorophore at the excited state . Then, the fluorescence quenching of the sensing film for organic amines becomes amplified, which induces a low detection limit.…”

Detection of high-energy compounds using photoluminescent silicon nanocrystal paper based sensors

“…6,7,9 Modern methods for detecting explosives include gas chromatography coupled with mass spectrometry, ion mobility spectrometry, surface enhanced Raman spectroscopy, and energy dispersive X-ray spectroscopy. [10][11][12][13] Unfortunately, all of these methods are infrastructure intensive and cannot be readily implemented in the eld or outside a laboratory setting.…”

UV-vis spectrophotometric determination of trinitrotoluene (TNT) with trioctylmethylammonium chloride as ion pair assisted and disperser agent after dispersive liquid–liquid microextraction

“…A c c e p t e d M a n u s c r i p t 5 liquid microextraction (DLLME) is considered a convenient and efficient ME technique that was first developed by Rezaee et al [24]. The basic principle of this method is the dispersion of extraction solvent assisted with a disperser solvent within an aqueous solution that generates a very high contact area between the aqueous phase and the extraction solvent.…”

“…Various methodologies have been reported for identification or determination of TNT, including optical colorimetric sensors [4], fluorescent polymers [5,6], electrochemical sensors [7,8] quartz crystal microbalance [9], solid phase microextraction (SPME)-HPLC…”