Inventors: Dino Villagran, Paul Westerhoff, Jonathan Josue Calvillo Solis, Michael Wong
Description:The study presents a sensing platform using a glassy carbon electrode (GCE) coated with gold nanoparticles (AuNPs) for the electrochemical detection of perfluorooctanoic acid (PFOA) in water. The AuNPs were electrodeposited onto the GCE using chronoamperometry and characterized through cyclic and linear sweep voltammetry, as well as scanning electron microscopy. PFOA quantification was achieved through Square Wave Cathodic Stripping Voltammetry, showing linearity in the 1-25 ppb concentration range. The method exhibited a low limit of detection (0.228 ppb) and quantification (0.759 ppb), with potential for further improvement using electrodes with larger surface areas. Standard addition experiments in tap water samples demonstrated precision (2.36-3.08% RSD), and the modified electrodes exhibited consistent and reproducible results over 100 cycles with only a 2.4% current drop.
Abstract:A glassy carbon electrode (GCE) functionalized with gold nanoparticles (AuNPs) was used to electrosense perfluorooctanoic acid (PFOA) aqueous media. Gold nanoparticle electrodeposition is controlled via chronoamperometry (CA) and the gold nanoparticle properties (including electrode coverage, size, morphology, etc.) was characterized by analytical methods such as cyclic and linear sweep voltammetry, and Scanning Electron Microscopy. Quantification of PFOA was performed by Square Wave Cathodic Stripping Voltammetry (SWCSV) in a concentration range of 1-25 ppb. Calibration curves shows linearity between the concentration and the striping current (Δi). The limits of detection (LOD) and quantification (LOQ) were 0.228 ppb and 0.759 ppb respectively. These limits can be enhanced with electrodes with larger surface area. Standard addition of PFOA to tap water samples show that these modified electrodes have a relative standard deviation range of 2.36-3.08%, which is considered precise. These modified electrodes show consistent and reproducible data with a current drop of only 2.4% over 100 cycles.
Issue Date: 03/04/2025
Application Date: 06/15/2023
Post Date: 12/05/2023
UTEP Docket No: 2022-008
