Luminescence Lifetime-Based Sensing Platform Based
on Cyclometalated Iridium(III) Complexes for the Detection of Perfluorooctanoic
Acid in Aqueous Samples
posted on 2024-01-16, 16:05authored byKun Zhang, Andrew J. Carrod, Elena Del Giorgio, Joseph Hughes, Knut Rurack, Francesca Bennet, Vasile-Dan Hodoroaba, Stuart Harrad, Zoe Pikramenou
Luminescence lifetimes
are an attractive analytical method for
detection due to its high sensitivity and stability. Iridium probes
exhibit luminescence with long excited-state lifetimes, which are
sensitive to the local environment. Perfluorooctanoic acid (PFOA)
is listed as a chemical of high concern regarding its toxicity and
is classified as a “forever chemical”. In addition to
strict limits on the presence of PFOA in drinking water, environmental
contamination from industrial effluent or chemical spills requires
rapid, simple, accurate, and cost-effective analysis in order to aid
containment. Herein, we report the fabrication and function of a novel
and facile luminescence sensor for PFOA based on iridium modified
on gold surfaces. These surfaces were modified with lipophilic iridium
complexes bearing alkyl chains, namely, IrC6 and IrC12, and Zonyl-FSA surfactant. Upon addition of PFOA, the modified
surfaces IrC6-FSA@Au and IrC12-FSA @Au show the largest change in the red luminescence signal with changes
in the luminescence lifetime that allow monitoring of PFOA concentrations
in aqueous solutions. The platform was tested for the measurement
of PFOA in aqueous samples spiked with known concentrations of PFOA
and demonstrated the capacity to determine PFOA at concentrations
>100 μg/L (240 nM).