Ultrasensitive detection of forever chemical perfluorooctanoic acid using two-dimensional aluminum quasicrystal

Abstract

Per- and poly-fluoroalkyl substances (PFAS), specifically perfluorooctanoic acid (PFOA), often referred to as “forever chemicals,” are pervasive environmental pollutants and pose significant threats to human health, contaminating water sources globally. Here, we have demonstrated a simple and easily scalable electrochemical sensor based on two-dimensional (2D) aluminum-based multicomponent quasicrystals (2D-Al QC) for the ultrasensitive detection of PFOA. The linearity range extended from 1 μM to 1 pM, with the limit of detection (LOD) and limit of quantification (LOQ) achieved are 0.63 pM and 1.90 pM, respectively. The sensor was evaluated for selectivity with other interfering compounds, repeatability, and reproducibility for seven similar electrodes with a deviation of 0.8%. The stability of the sensor was analysed after ninety days and showed a minimal variation of 15%. The fluorine atoms of the PFOA molecules interacted with the Al atoms of the 2D-Al QC, which is observed in the Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. This interaction has been corroborated by the molecular dynamics simulation and confirms the defluorination of PFOA molecules during the electrochemical oxidation reaction. The current work demonstrates that the 2D-Al QC offers a promising platform for the rapid and highly sensitive detection of PFOA, potentially addressing current environmental monitoring challenges.