Ability of various materials to detect explosive vapors by fluorescent technologies: A comparative study.
ABSTRACT For the development of fluorescent sensors, one of the key points is choosing the sensitive material. In this article, we aim at evaluating, under strictly identical experimental conditions, the performance of three materials for the detection of dinitrotoluene (a volatile marker of trinitrotoluene) through different parameters: response time, fluorescence intensity, sensitivity, reversibility, reaction after successive exposures and long-term stability. The results are discussed according to the nature of the sensitive materials. This first study rendered it possible to select a conjugated molecule as the best sensitive material for the development of a lab-made prototype. In a second part, the selectivity of this particular sensitive material was studied and its ability to detect TNT could be demonstrated.
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ABSTRACT: Nanofibers with distinct luminescent property were facilely fabricated by electrospinning from porphyrinated polyimide and demonstrated as a kind of novel sensory material for trace detection of TNT vapor (10 ppb). Covalently bonding of porphyrin fluorophores into the polyimide main chains reduces the aggregation-caused fluorescence self-quenching of porphyrin and improves the physicochemical stability of the polyimide nanofibers. The large surface area-to-volume ratio and hence good gas accessibility endow the porphyrinated nanofibers with much more remarkable fluorescent quenching behavior toward trace TNT vapor than its spin-coating dense film counterparter. Besides TNT, 2,4-dinitrotoluene (DNT), 2,4,6-trinitrophenol (PA) and nitrobenzene (NB) could also quench the fluorescence of the porphyrinated nanofibers, but the quenching efficiency is much lower than that of TNT. An apparent binding affinity constant of (2.37 ± 0.19) × 107 L/mol was calculated from SPR analysis, confirming that the porphyrinated nanofibers is a promising alternative for TNT detection.Sensors and Actuators B: Chemical. 184:205–211.