posted on 2024-01-23, 17:06authored bySalma Hafed-Khatiri, Andrés F. Quintero-Jaime, David Salinas-Torres, Francisco Montilla
Electrofluorochromism (EFC) is a phenomenon widely employed
for
the development of optoelectronic devices. In this work, we applied
EFC as a powerful tool in sensing applications. The ability to tune
the photoluminescence emission by controlling the applied potential
may help maximize the response to target molecules. We have explored
the EFC of the conjugated copolymer poly[9,9-dioctylfluorene-alt-benzothiadiazole] (F8BT) to design an electrofluorochromic
sensor able to detect emerging pollutants with a significant impact
in the marine ecosystems. In particular, a sulfonic acid-based chemical
sunscreen (Ecamsule) was used as a model molecule. The photoluminescence
emission modulation is affected by the presence of Ecamsule, which
is attributed to the enhanced quenching process of F8BT during the
p-doping process. The quenching is due to the formation of exciplex-like
within the conjugated film upon the insertion of the organic anionic
molecule in the polymer chain. The developed F8BT-based electrofluorochromic
sensor displays a low limit of detection and good selectivity in the
presence of interfering anions that are common in seawater.