2026-04-17T10:26:11Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/76042023-04-20T11:32:57Zcom_10259_4313com_10259_5086com_10259_2604col_10259_4314

2023-03-28T08:09:51Z urn:hdl:10259/7604 Paper-Based Probes with Visual Response to Vapors from Nitroaromatic Explosives: Polyfluorenes and Tertiary Amines Aguado, Roberto Santos, A. Rita M. G. Vallejos Calzada, Saúl Valente, Artur J. M. Cellulose Explosive detection Meisenheimer complex Nitroaromatics Paper analytical devices Polyfluorenes Although it is well-known that nitroaromatic compounds quench the fluorescence of different conjugated polymers and form colored Meisenheimer complexes with proper nucleophiles, the potential of paper as a substrate for those macromolecules can be further developed. This work undertakes this task, impregnating paper strips with a fluorene-phenylene copolymer with quaternary ammonium groups, a bisfluorene-based cationic polyelectrolyte, and poly(2-(dimethylamino)ethyl methacrylate) (polyDMAEMA). Cationic groups make the aforementioned polyfluorenes attachable to paper, whose surface possesses a slightly negative charge and avoid interference from cationic quenchers. While conjugated polymers had their fluorescence quenched with nitroaromatic vapors in a non-selective way, polyDMAEMA-coated papers had a visual response that was selective to 2,4,6-trinitrotoluene (TNT), and that could be easily identified, and even quantified, under natural light. Far from implying that polyfluorenes should be ruled out, it must be taken into account that TNT-filled mines emit vapors from 2,4-dinitrotoluene (DNT) and dinitrobenzene isomers, which are more volatile than TNT itself. Atmospheres with only 790 ppbv TNT or 277 ppbv DNT were enough to trigger a distinguishable response, although the requirement for certain exposure times is an important limitation. 2023-03-28T08:09:51Z 2023-03-28T08:09:51Z 2022-05 info:eu-repo/semantics/article http://hdl.handle.net/10259/7604 10.3390/molecules27092900 1420-3049 eng Molecules. 2022, V. 27, n. 9, 2900 https://doi.org/10.3390/molecules27092900 info:eu-repo/grantAgreement/Portugal 2020//POCI-01-0247-FEDER-021874//Produtos e Tecnologias Inovadores a partir do Eucalipto/InPaCTus/ info:eu-repo/grantAgreement/FCT//UID%2FQUI%2F00313%2F2020/PT/ http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Atribución 4.0 Internacional MDPI