Pyridine-Based Small-Molecule Fluorescent Probes as Optical Sensors for Benzene and Gasoline Adulteration
Thiago Jacobsen Peglow,
Marcelo Marques Vieira,
Nathalia Batista Padilha,
Bianca T. Dalberto,
Henrique de Castro Silva Júnior,
Fabiano Severo Rodembusch,
Paulo Henrique Schneider
Affiliations
Thiago Jacobsen Peglow
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Marcelo Marques Vieira
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Nathalia Batista Padilha
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Bianca T. Dalberto
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Henrique de Castro Silva Júnior
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Fabiano Severo Rodembusch
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Paulo Henrique Schneider
Laboratory of Molecular Catalysis (LAMOCA), Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), P.O. Box 15003, Porto Alegre 91501-970, RS, Brazil
Here we present simple fluorophores based on the pyridine core, obtained with straightforward synthetic methodologies. These compounds present in solution absorption maxima in the UV region and fluorescence emission of between 300 and 450 nm, depending on the solvent and chemical structure of the fluorophore. The nature of the solvent was shown to play a fundamental role in their excite-state deactivation, which allowed successful exploration of these compounds as optical sensors for benzene and fuel adulteration in gasoline. In ethanolic solution, upon the addition of benzene, in general the fluorophores presented fluorescence quenching, where a linear correlation between the emission intensity and the amount of benzene (quencher) was observed. In addition, the application of an optical sensor for the detection of fuel adulteration in commercial standard and premium gasoline was successfully presented and discussed. Theoretical calculations were also applied to better understand the solvent–fluorophore interactions.
