Ion-transfer electroanalytical detection of perfluorooctanoic acid at a liquid–liquid micro-interface array†

Abstract

Per- and polyfluoroalkyl substances (PFAS) are synthetic materials that bioaccumulate and are environmentally persistent. Due to their serious health threats, including to humans, new methods for the sensing of PFAS are needed. Here, we report the electrochemical behaviour of perfluorooctanoic acid (PFOA) via ion transfer voltammetry at an array of microinterfaces between two immiscible electrolytic solutions (μITIES). Investigation of electrochemical sensing of PFOA at the μITIES array by voltammetry showed that differential pulse stripping voltammetry (DPSV) with a 300 s preconcentration time was the most sensitive approach. This enabled a limit of detection (LOD) of 1.2 nM. Matrix effects of different types of samples, like tap water, and aqueous phases spiked with a protein (bovine serum albumin) or complexing reagent (β-cyclodextrin), on the analytical performance of PFOA were evaluated. The findings presented here provide a basis for sensing of PFOA using ion transfer voltammetry.