A "turn-off" fluorescent sensor based on electrospun polycaprolactone nanofibers and fluorene(bisthiophene) derivative for nitroaromatic explosive detection

Anna Paula L A Santos; Gerard O Deokaran; Cristiane V Costa; Lillia I L M Gama; Edu G Mazzini Júnior; Alexandro M L de Assis; Johnnatan D de Freitas; William R de Araujo; Roberta P Dias; Júlio C S da Silva; Ligia M M Costa; Adriana S Ribeiro

doi:10.1016/j.forsciint.2021.111056

A "turn-off" fluorescent sensor based on electrospun polycaprolactone nanofibers and fluorene(bisthiophene) derivative for nitroaromatic explosive detection

Forensic Sci Int. 2021 Dec:329:111056. doi: 10.1016/j.forsciint.2021.111056. Epub 2021 Oct 14.

Affiliations

¹ Chemistry and Biotechnology Institute, Federal University of Alagoas, Campus A. C. Simões, 57072-970 Maceió, AL, Brazil.
² Chemistry and Biotechnology Institute, Federal University of Alagoas, Campus A. C. Simões, 57072-970 Maceió, AL, Brazil; Criminalistics Institute of Alagoas, 57020-070, Maceió, AL, Brazil.
³ Portable Chemical Sensors Lab, Institute of Chemistry, State University of Campinas, 13083-970, Campinas, SP, Brazil.
⁴ Chemistry and Biotechnology Institute, Federal University of Alagoas, Campus A. C. Simões, 57072-970 Maceió, AL, Brazil; Technical and Scientific Section of Alagoas, Federal Police, 57025-080, Maceió, AL, Brazil.
⁵ Federal Institute of Alagoas, Campus Maceió, 57020-600, Maceió, AL, Brazil.
⁶ Federal University of Pernambuco, Campus Agreste, 55014-900 Caruaru, PE, Brazil.
⁷ Chemistry and Biotechnology Institute, Federal University of Alagoas, Campus A. C. Simões, 57072-970 Maceió, AL, Brazil. Electronic address: aribeiro@qui.ufal.br.

PMID: 34736045
DOI: 10.1016/j.forsciint.2021.111056

Abstract

The preparation of fluorene(bisthiophene)-based fluorescent nanofibers for nitroaromatic explosive detection provides a convenient rapid and low-cost strategy aiming at forensic applications. Polycaprolactone (PCL) and fluorene(bisthiophene) derivative (FBT) nanofibers were obtained by electrospinning technique as a free-standing mat and characterized by SEM, FTIR, thermal analysis and fluorescence spectroscopy. The PCL/FBT nanofibers presented high sensitivity towards 2,4,6-trinitrotoluene (TNT) and picric acid (PA), with fluorescence quenching (turn-off mechanism), and selectivity to another kind of explosives. The free-standing mats were used as a cloth strip that was swiped on surfaces contaminated with TNT traces allowing its visual detection under UV light source. These findings are particularly important for the development of a facile and promising strategy to assembly portable optical devices for nitroaromatic explosive detection.

Keywords: Electrospinning; Explosives; Fluorene derivative; Fluorescence.